ABP yr 2
ESS assumptions
• Infinite population size • Asexual (haploid) reproduction • All strategies are specified • Either pairwise contests occur or one individual competes against a group
implications for psychiatric diseases
• circadian disorganisation, alzheimer's v disrupted, degeneration in SCN • Disruption to circadian rhythm as indicator?
Transitive inference
E.g. if... Alan is taller than John, John is taller than Sarah- who is tallest?
Conwy Lloyd Morgan
Lloyd Morgan's canon 1894 Find the simplest explanation
Behavioural genetics
does behavioural variation have a genetic basis meaning of 'genes for behaviour' EVIDENCE for genetic basis Single gene mutations spontaneous induced transgenic genetic transformation of Arrhythmic fruit flies The per gene controls circadian rhythms. The protein PER is produced early on and then another enzyme produced by another gene degrades it so it gradually decreases throughout the day. Wildtype have a consistent pattern of daytime activity, arrhythmic mutants have an inconsistent pattern of stopping and starting activity across the 24 hours. There is a mutant in humans that shifts the activity time forwards, so that people with the mutation fall asleep at 7:30pm and wake at 4:30am genetic transformation of species-typical song song types transformed by inserting the genes from another species. A is the normal melanogaster song, and C is the normal simulans song, B and D are the swapped versions genetic transformation of behaviour in mice Normal maternal behaviour (fosB+) Inactive fosB gene, female does not retrieve pups (fosB-) The fosB gene and maternal care - affects development of the preoptic area of the brain and thus sensory integration DOESN'T demonstrate single gene determines maternal behaviour Olfactory stimuli activate neurons, causing chemical changes that trigger fosB gene activity; when the gene's information is expressed, a chemical product is made, which then is available as an environmental trigger to affect the activity of other genes and thus, the biochemistry of cells and the development of the individual. ALSO The Oxt gene and social 'amnesia' - affects oxytocin secretion in the brain and the ability to remember social odours MORE EVIDENCE FOR GENETIC BASIS Inbred strains (lower genetic diversity than wt so potentially less material for behavioural adaption to work w) Chromosomal changes euploidy aneuploidy breakage (all these changes can express themselves as an altered BEHAVIOURAL phenotype) Hybridisation polygenic traits Selection experiments Geographical variation (these are ways you can test for evidence of genetic basis for behaviour) e.g. hybridisation and song in crickets (cross breeding 2 spp. disrupts courtship song of hybrids) can also select behavioural traits/strains artificially can even select for something as complicated as territoriality. This was done in Drosophila by selecting lines that were housed with patchy food resources that needed guarding, or by leaving them with a continuous food source that there was no competition for. The ones housed with patchy food resources (food cups) had to become territorial to survive and breed Neuroanatomical correlates species-specific learning, memory, locomotion sexual dimorphism C. elegant touch-insensitive mutants Mutations in mec-7 mean that there is no touch sensitivity on the body wall and normal locomotion activity is impaired. mec-1 being mutated means that the touch receptor processes are not attached properly to the body wall. If unc-86 is mutated then the differentiating neuronal lineages will not be correctly determined, and the neurons are not present. If mec-3 is mutated the differentiation and maturation of the mechanosensory neurons is stopped and the worm is insensitive to weak and strong touches. ALSO cross eyed siamese decussation: crossing of millions of axons, needs to be accurate or errors occur, this process accounts for the 180deg inversion in the visual syst of mammals/can make for a more robust structure in siamese it's gone wrong' bunching up of neuronal inputs in visual cortex relates to coat colour in some pedigree lines To sensitive allele for tyrosinase > Localised melanin production (lack of melanin in pigment epithelium, impaired development of retinal ganglion cells) > Impaired decussation and visual perception same mutation that leads to pigment being expressed only in the extremities of the cat also leads to the retinal ganglion cells in the eyes developing incorrectly genetic pathway from having to cope behaviourally with impaired vision is very indirect and stems from the mutation that also produces a different coat colour
Cognition
"...the mechanisms by which animals acquire, process, store, and act on information from the environment." Darwin behaviour and psychology also subject to evolution Darwin observed commonalities between species' mental characteristics comparative psychology
territory
"A more or less exclusive area defended by an individual or group" Davies & Houston 1984 why defend a territory? survival benefits e.g. acorn woodpeckers mating benefits e.g. dickcissels (bird) feeding benefits e.g. surgeonfish costs Testosterone implants increase territorial activity by males, but they reduce survival unless additional food is made available e.g. Yarrow's spiny lizard optimal territory size 'economic defendability' territory size should be adjusted to max energy gain e.g. rufous hummingbird too large a territory to defend easily- decreases size adjusts size of defended territory according to economic defendability of it doesn't waste energy territory size should depend on resource availability e.g. flower density more dense- smaller territory Territories should occur at intermediate resource densities e.g. honeycreepers (l'iwi) only seriously defend territories when there are some flowers to defend and they are still a bit limited in numbers. If there are no or too many flowers, it is pointless to hold a feeding territory Territory size should respond to competition e.g. sanderling bird Increased intruder pressure decreases territory size, not prey density
what is a group?
"Any set of organisms...that remain together for a period of time interacting with one another to a distinctly greater degree than with (others)" Wilson Degree of proximity over time Sufficient proximity to permit information exchange and coordination ('elective group size') Proximity sought actively - based on social attraction (as opposed to incidental proximity due to e.g. shared environmental requirements)
Salience and 'constraints on learning'
'Garcia effect' What is relevant to the animal in it's natural habitat? Animals can only associate stimuli that is relevant to their world. Rats can associate a taste with nausea that sets in later, even hours later, and form a conditioned response, but they cannot associate a taste with a shock or a noise as it is not relevant to foraging. They can form an association between a noise and a shock because a noise might precede injury in the wild.
Encephalisation quotient
(EQ) is a comparison of that ratio against a typical animal of that group (e.g. class or order). Calculation: C = E/Sr Where C = EQ; E = brain weight; S = body weight; r = exponential constant (depends on animal group)
intersexual selection
-non-genetic / direct benefits in kind - e.g. territory owner with crucial resources, nuptial gifts, fertilisation capacity e.g. Spermatophylax gifts in bush crickets viability indicators ('good genes') - e.g. health, developmental stability, immunocompetence -non-genetic / direct Benefits in kind - e.g. territory owner with crucial resources, nuptial gifts, fertilisation capacity do females benefit from choosing?e.g. barn swallows- males with longer tails were paired up to females faster, their chicks had fewer mites even when being raised by different parents, and males that were mitey in general had mite-ridden offspring, regardless of who was raising them. The second set of graphs show that mites have an effect on male ability to feed chicks and on chicks ability to fledge the nest.
neuronal circuit for driving adductor muscle motor neurones and behaviour
1. photoreceptor 2. photoreceptor axon 3. 2nd order I-cell, in supra-oesophageal ganglion 4. circumeosophageal connective DIAGRAM
History of animal behaviour
1930s: Simple automated machines that we can understand provided we can work out the pathways. Little machines that blindly follow fixed action patterns in response to external stimuli. 1970s: scheming tacticians, weighing up the costs and benefits of every course of action and always choosing the best (or most optimal) one. Today? Something between the two views
roundworms/nematodes
4 nerve cords running body length dorsal associated w motor control 2 lateral associated w sensory input ventral associated w both nerve ring and ganglia in head surrounding pharynx sensory nerves extending forwards towards anterior end Neurons do not produce a voltage-sensitive sodium current. They seem to manage with just voltage-gated calcium channels. May pre-date voltage-gated sodium channels. C. elegans Neurons do not produce a voltage-sensitive sodium current. They seem to manage with just voltage-gated calcium channels. May pre-date voltage-gated sodium channels. roller mutants 14 diff genes 'bag of worms' - numerous genes involved in vulval muscle control/development
Plasticity mediated via 5-HT (serotonin)
5-HT addition can mimic habituation also increase S-cell excitability Pharmacological block of certain 5-HT receptors can eliminate sensitization 5-HT depletion severely modifies these behaviors 5-HT neurotransmitter release from sensory cells to Interneurons responsible for shortening (C-cells above) 5-HT is a neuromodulator S-cell controls local response as well as that of other segments Revisit with Aplysia californica
history of NS
580mya nerve nets 520mya fish w distinct lobes assisted by Cambrian explosion? Another 0.5 billion years to arrive at the human nervous system with extreme cephalisation.
patch choice solution: marginal value theorem
A is arrival. T opt is the optimal time for departure, G is maximum gain. B to B''' are different travel distances between patches, B for between. As travel time to patches becomes longer, optimal stay time in a patch also increases. DIAGRAM patch choice predictions diagram Optimal search time in a patch is greater when travel time between patches is longer DIAGRAM S=short dist, L=long
Learning sets and concept formation
A learning set implies that if we have encountered similar problems in the past we are often better at solving the current problems. We can apply general rules but the details will differ. The animal understands the basic principles of the task. Win-stay lose-shift means if the behaviour is rewarded, the animal will make the same choice next time, if not, he will shift to the other option. So if the food is not under the blue cup, he will shift to the red cup. He can also be taught to go the other way, if he wins with the food under the red cup, he can learn that the next time it will be under the blue cup. The graph shows the formation of a learning set in a rhesus monkey. As a monkey encountered more variants of an object discrimination problem, it became quicker at solving new versions of the problem, meaning that performance improved faster in later discriminations. In this case the monkey learned to adopt a win-shift, lose-stay strategy. So the objects continually changed, but the monkey had worked out the principle of the task, regardless of how many different objects were presented. The African grey parrot in the picture can tell you several things about the two objects, he can separate out that they are red and green, small and big, AND that they are both keys! Mammals have differing abilities, monkeys do best in these discrimination tasks; rats and squirrels do the worst. Intelligence not a hierarchy. The species might need to be tested in different ways. Problems: performance in learning sets still highly dependent on task modality concept/category learning does not necessarily imply the same as in humans
classical conditioning
AKA: conditioned reflex Type 1, respondent or Pavlovian conditioning Pavlov's dog 1920s performed his famous experiment using dogs and meat powder. When the dog hears the CS it expects the US and produces the CR when he hears the bell ring. In other words, the dog has learned to predict food when it hears the bell. If it were not restrained it might wag it's tail or beg, but here what was measured was salivation. The important relationship in classical conditioning is the relationship between the two stimuli. Almost anything, even pain, can become a conditioned stimulus. Quite seemingly complex behaviours can be the product of classical conditioning, and not based on complex cognition. (UR) < unconditioned stimulus (US) - meat powder >< conditioned stimulus (CS) - bell > conditioned response (CR) -salivation >< unconditioned response (UR) - salivation classical conditioning conditioned eye-blink response in rabbits The rabbit is held in an apparatus and given a shock behind the eye (the US) which causes it to blink (the UR) and a CS of a sound. The conditioned response is an eyeblink upon hearing the sound. The CR can become extinct after a break in training or if the rabbit was only partially reinforced (say the shock was not very strong). Classical conditioning can be easily reversed, which we can see in the rat example. If the CS is presented with no US, or there is a break in training, after a time, the animal will stop responding with the UR. Factors affecting efficacy 1 Relative timing of US and CS CS preceding the US generally works best, but CS can appear long after US (flavour and resulting sickness) or even become a time of day (temporal conditioning) Degree of 'overtraining' persistence in pairing of US and CS beyond needed to establish a CR reduces the tendency to extinction Blocking - if an animal has learned that a light predicts food, then later the light is paired with a tone, the animal is unlikely to learn that the tone also predicts food, it is blocked by the light stimulus. Overshadowing - If an animal is trained to expect a shock when it sees a light and hears a tone, it will react less intensely to either a light or a tone presented on their own. This relies on the fact that both stimuli have equal salience to the animal Salience/'constraints on learning' - is how much a stimulus stands out against the background of the environment it is presented in. A bright light is more salient than a dim light, a loud tone more salient than a soft tone. It also depends on the sensory capabilities of the animal in question, so that some stimuli may be more relevant to some species than others eg: odours are more salient than colours for rats (who are nocturnal). We will have some examples later on.
operant conditioning
AKA: conditioned reflex Type 2, instrumental conditioning or 'trial-and-error' learning Mechanism of learning is very similar to classical conditioning, but here the animal makes it's own associations. There are two traditional techniques: the puzzle box and the skinner box, this time without the electrified grid. The puzzle box, the animal opens a latch to escape and get to food, invented in 1898 by Thorndike. In the Skinner box in this setup, the animal gets hungry, explores the cage and eventually presses the button that makes food appear. The animal makes it's own association between it's actions and the reward. The Skinner box is similar, the pigeon explores the space and pecks at the key when it is lit up, then some food appears, the bird makes it's own associations between it's actions and rewards. In the video, the pigeon has to peck the key a certain number of times to get the food. Rats in a maze get better over time as they make the association with taking a particular course and getting to the food reward at the end. Performance, in terms of time it takes, latency to get going and reducing errors all improve as the associations between behaviour and reward are made. efficacy of operant conditioning continuous reinforcement (each performance rewarded) > variable-ratio schedule (Random variation in the number of performances needed for reward) ALSO > fixed-ratio schedule (rewarded after a certain number of performances) Continuous reinforcement produces the strongest and most consistent responses. Every performance is rewarded. Fixed-ratio schedules mean the animal has to perform the behaviour a certain number of times to get the reward. A variable ratio means that the behaviour has to be performed a random number of times to get the reward, a good real life example is a slot machine. This type of reward makes it very hard for the behaviour to go extinct, which is why gambling is addictive.
social behaviour
Aggregation versus territoriality Interacting effects of different selection pressures Social organisation why live in groups? Genes, selection and aggregation e.g. single gene diffs in C. elegans Mutations (NPR1) affecting nociceptive neurons mediate social vs. solitary activity in the presence of bacterial food if they have the highly active allele of the gene, they are solitary, and if it is very low in activity, they feed in groups. it is theorised that under adverse environmental conditions they clump together to feed, like many invertebrate and vertebrates Costs and benefits of group living Relationships between foraging and anti-predator benefits ('many eyes' effect and 'double benefit' of grouping e.g. eastern grey kangaroo- less time needed to be vigilant in bigger groups, higher feeding rate)
aphid alarm pheromone
Alarm pheromone in aphid Identified as (E-Ɓ-farnesene Alarm response (dispersal) of Myzus persicae to volatiles released by transformed and wild-type Arabidopsis thaliana The pheromone also acts as a kairomone and attracts the parasitoid wasp Diaeretiella rapae (cabbage aphid parasitoid) which can reduce the population of aphids. parasitoids spent more time on transformed Arabidopsis thaliana plants Many plants also make EβF but the co-synthesis of inhibitory compounds allows aphids to overcome the potential repellancy Transgenic plants making EβF are less attractive to aphids and more attractive to aphid parasitoids transformed wheat tested, not conclusive • Aphids, more EBF, more antennae stimulation • V sensitive to this chemical • More EBF, higher response %
signalling and communication
All pieces of information are sent by senders and received by receivers Cues are incidental sources of information detected by unintended receivers Eg: The noise an animal makes as it moves through undergrowth Signals have evolved specifically to alter a receiver's behaviour Eg: The vibration of a psyllid against a plant stem to attract mates
Group selection (Wynne-Edwards 1963)
Animals are variously adapted to control their own population densities The mechanisms work homeostatically to adjust population densities to changing levels of resource The mechanisms depend partly on the substitution of conventional 'prizes' for resources as proximate objects of competition Prizes are things like territories or dominance status Groups of animals adopting such conventional rules of competition constitute a society Selection chooses between societies, not individuals. Leads to evolution of social behaviour through group selection Individuals sacrifice themselves for the good of the group out of favour w many modern biologists Non-Darwinian, not at gene level shown experimentally w flour beetles in bottles of grain in the lab. The flour beetle experiment was to produce two types of populations, one large and fast growing, and the other small and slow growing. The small slow-growing populations out-competed the larger faster-growing populations in taking longer to go extinct when competing with each other for an un-renewed food resource. The small slow-growers produced fewer adults and also cannibalised each other more so that the population remained small. Not likely to work in a natural population, because it requires effective genetic and ecological isolation, and no possibility of a cheating mutant to crop up, this is rarely the case in natural animal populations.
Clever Hans
Answer qs/arithmetic never looked at the people/objects needed to count or at the words needed to read responding to external signs, even when experimenter unknown Presence of experimenters is important to think about in animal studies (experimenter should not be sensed or should be blind to answers)
parent-offspring conflict
Assume fixed total resources for offspring Parents want to distribute resources equitably to all n offspring Offspring want more than 1/n but not all since they are related to siblings Difference between parent and offspring optima increases as relatedness decreases e.g. wallaby e.g. brown-headed cowbird brood parasite begging loudness increases as relatedness within nest decreases Indirect evidence that parent offspring conflict is greater in nests with low relatedness. The brown headed cowbird is a brood parasite that does not eject or kill the chicks of it's host. But it does beg more loudly than them time of weaning predict that offspring in families with mixed paternity should demand more care than offspring in monogamous families If reproductive value declines with maternal age, then older females should be willing to expend more on parental care. e.g. red deer Kidney fat ratio is an indicator of how healthy and well-fed the calf is. Increases with increasing maternal age, as each calf could be her last and she wants to make sure it will survive. When you are young, you can always have more.
2 action procedure
Atkins and Zentall (1996) Trained Japanese quail to manipulate a treadle for a food reward Peck with beak or step with foot Observers made more responses with the same part of their body as used by the demonstrator Not stimulus enhancement Also, quail more likely to copy behaviour if they observed the demonstrator get a reward Chimps and children Horner & Whiten (2005) Chimpanzees and young human children shown demonstrations of how to open a puzzle box Demonstrations included unnecessary behaviours When box was opaque, chimps and children imitate sequence When box was transparent, only children imitated. However, chimpanzees didn't perform the unnecessary behaviours Imitation employed at the expense of efficiency in humans? Emulation employed at the expense of true copying in chimps?
Personality and foraging
Barnacle geese The boldest birds, as ranked in a novel object test, were also given the highest dominance scores after observations of their behaviour in the flock. Novel object score was the minimum distance the goose approached the novel object (green plastic mat) in a 10 minute trial. The birds that were approached the closest to the novel object were also more likely to lead the flock in another trial and to arrive at the food first in another trial. Bolder birds reaped foraging rewards by getting access to resources first, but also led the flock to these resources.
Latent learning
Behavioural responses to stimuli that occur without reinforcement of the learning formation of associations that appear to bring the animal neither reward nor punishment (although novel experiences may themselves constitute a reward). There is a delay between exposure to the learning situation and the performance of a behaviour pattern that demonstrates the effect of learning. For example, rats will explore a maze without apparent reward or punishment and will remember the information they obtain; later, when rewards are presented, those rats will perform better at finding their way through the maze than rats with no exploratory experience.
Inclusive fitness
Benefit of behaviour = (benefit to self - cost to self) + (0.5 benefit to brother - 0.5 cost to brother) + (0.25 benefit to grandchild - 0.25 cost to grandchild) + (0.125 benefit to first cousin - 0.125 cost to first cousin) + ... Phenotypic altruism Haplodiploidy in hymenoptera - bees, wasps and termites. Sisters are more closely related to each other than they are to their mother, or would be to their own offspring, so help you mother make more sisters and feed them when they are larvae.
One of two parents
Birds are more likely to exhibit biparental care as both parents can feed and protect young and two often do better than one Fish and amphibians typically only guard eggs and don't feed. One parent can do this as well as two why male only parental care? care can cost females more St. Peter's fish Mouthbrooding results in weight loss due to feeding reduction males lose less weight A female-biased sex ratio increases cost of brood care for males because parental care detracts from mating.
e.g. choice associated w appropriate adaptive 'skills'
Blue tits prefer deciduous woods, Coal tits prefer coniferous woods adaption? artificial forest, tested how much time wild/hand reared birds spent in preferred habitats spent most time in habitats they originated from each habitat requires diff feeding skills? Deciduous - pull and tear leaves to get insects, and hang off the end of springy thin branches to reach the tips. Coniferous - poke and probe in crevices. feeding trials Types of containers in which food was hidden to test adaptive 'skills' Coky, Hacky and Springy were deciduous and Proby, Pully and Hoppy were coniferous. coal tits were more successful than blue tits in getting food when conditions simulated a conifer forest time taken to get food- longer=less efficient blue tits took longer to get the food when conditions simulated a conifer forest, and coal tits took longer to get the food when conditions simulated a deciduous forest HABITAT SPECIFIC FORAGING SKILLS
costs/benefits of group living
COSTS competition e.g. fieldfare bird- bigger colony, lower nesting survival increased transfer of pathogen cliff swallows BENEFITS anti-predator ('many eyes' e.g. white fronted geese; dilution effect-chance of an individual being captured by a predator decreases as group size increases, since predator only takes a single or a limited amount of prey in each attack e.g. water skaters; confusion effect; selfish herd effect e.g. starlings) foraging (local info about food e.g. pigeons learning to pierce a coloured lid on box of food by observing others; producers-scroungers e.g. pigeons- need almost equal ratio of producers to scroungers, scroungers suppress activity of producers if too many, and dom animals more likely to be scroungers)
Teaching
Caro and Hauser (1992) Teacher must modify its behaviour in the presence of naïve observer There is a cost to the teacher (or no immediate benefit) The pupil acquires knowledge or learns a skill earlier or faster or more efficiently than it otherwise would have/not learn at all Meerkats Thornton & McAuliffe (2006) Helpers modify their behaviour in the presence of pups Helpers adjust killing or disabling prey depending on pup age Monitoring pups, nudging behaviour Helpers gained no direct benefit and incurred costs Monitoring time Prey might escape Helper provision is important in pups developing prey handling skills Experiment: 3 days training four dead scorpions four live, stingless scorpions an equivalent mass of hard-boiled egg (control) 6 tests: pup trained on live scorpions was the only successful handler, or had fastest handling time. All dead scorpion and control pups were pincered or pseudo-stung (only occurred once for live scorpion trained pups) Ants Franks and Richardson (2006), Richardson et al. (2007) Tandem running in temnothorax albipennis Ants show naïve ants where food is located Teacher modifies behaviour: runs slowly Cost to teacher: runs are much slower (x4 slower) Pupil learns skills: route is learned (but need more direct evidence)
Leech swimming - rhythmic behaviour/role of CPG
Central Pattern Generator Collection of interneurons that oscillate in activity Can be spontaneous, occur in isolation Can have multiple CPGs for different functions -Networks can be shared or discrete Can be imitated/modulated by higher centers or/and sensory input -Neuromodulation -Alter frequency and phase CPGs underlie rhythmic behavior Swimming -Leech, tadpoles, sea angels Walking -millipede Flying -locust Breathing Feeding intrinsic mechanism or rhythm generation • Only when coupled synchronous • Different to pacemaker • Collection of cells, not single cell • Multiple cells involved in controlling swimming body wave of swimming behaviour muscle tension alternates between dorsal and ventral surface Synchronous with neural activity in dorsal posterior nerve interactions of several, not one, neuron form pacemaker flat neuronal recording at rest, waves when swimming
Generic properties of receptor potential (RP)
Changes in ion channel activity Change in membrane permeability Account for virtually all RPs Different sensory receptors, different mechanisms of opening channels Direct effects Mechanosensitive Heat sensitive Ligand gated e.g. H+, capsaicin Indirect effects Light - cascade of biochemical events - channel events All belong to Transient Receptor Potential channels (TRPs) Transient receptor potential channel (TRP): VR1, polymodal 1 subunit of 4, tetramer
olfaction = basis for chem-eco
Chemical ecology examines the role of chemical interactions between living organisms and their environment, as the consequences of those interactions on the ethology and evolution of the organisms involved. Focus on the biochemistry of ecology and the molecules termed semiochemicals that function as signals to affect biological processes. Typically molecules which are readily diffusible organic substances of low molecular mass from secondary metabolic pathways, but also include peptides and other natural products. Chemical ecological processes mediated by semiochemicals include ones that are intraspecific) or interspecific (occurring between species). Various functional subtypes of signals are known.
Drug addiction
Conditioned tolerance Siegel, Hinson, Krank, and McCully (1982) Control group: dextrose in room A, dextrose in room B Experimental group: heroin in room A, dextrose in room B Test: overdose of heroin in A or B Less mortality in conditioned exp Esp. w heroin Cue exposure therapy Uses extinction (exposure to drug stimuli without drug) Mixed results (context important)
Learning
Classical conditioning (associations of stimuli) Operant conditioning (learning through consequences)
Phylogenetic tree of photoreception
Comparative physiology of photoreceptors Rhabdomeric (microvillar) and ciliary invert - rhabdomeric (R*=retinal activation, hv at r-Opsin>(arrestin) > Gq(>PIP2>DAG(phototransduction)) > TRP channels open (signal amp, current increase), TRPL > membrane potential, depolarise, histamine release increase) vert - ciliary (R*, hv at c-Opsin >(RK arrestin)> Gt >(PDE>cGMP(signal amp)> Na channels close, current decrease > membrane potential, hyper polarise, glutamate release decrease CNG) overview of phototransduction: rod > discs/rhodopsin mols > photon > 11-trans-retinal > bleaching > opsin > opsin > 11-cis-retinal and opsin are reassembled to form rhodopsin 11-trans-retinal > ATP >(enzyme)> ADP > 11-cis-retinal DIAGRAM
sperm competition
Competition between males to fertilise the same ovum Prevalent across the animal kingdom, including humans 2 ways to compete: Defensively (eg: behaviourally) Offensively (superior ejaculate/sperm) defensive: mate guarding e.g. blueband goby, king eider, bighorn sheep genital armoury e.g. penis scoops in insects (scoops out the first male's ejaculate, but also rips up the female's genital tract so she will be reluctant to mate again) strategic ejaculate investment offensive superior sperm e.g. passerine birds, polygamous (superior); bullfinch, monogamous (poorer quality)
assumptions of ideal free distribution
Competitors are free to sample all resource patches Competitors have perfect (ideal) knowledge of resource availability at each patch At the equilibrium distribution all competitors will be doing equally well (experience an equal rate of increase in reproductive potential) can occasionally be violated, esp. assumption that all competitors will do equally well in reproductive potential assumption that all competitors are equal/free to move around what about diff sizes? Small animals take up relatively fewer resources, so it becomes an ideal free distribution of competitive weights.
Limulus polyphemus (Atlantic horseshoe crab)
Compound (e.g. lateral) and simple (e.g. ventral) eyes Living fossils little change in 445 million years Ventral photoreceptor one of the most studied
who should receive care?
Concorde fallacy: past investment should not determine future investment - only prospects for future success
Alternative hypotheses for providing care in fishes and herptiles (amphibians and reptiles)
Confidence of paternity - parental care from parent with highest certainty - internal fertilisation - 86% maternal care - external fertilisation - 70% paternal care Order of gamete release - first to deposit gametes can leave - simultaneous fertilisation (most species) 78% paternal Association - whoever is closest to offspring when they need care - territorial males have external fertilisation
Usefulness of Leech bending and shortening behavior
Coordination of both excitatory and inhibitory outputs to achieve simple behavior Utilize minimal number of neurons Mapping of sensory to motor space Network calculate population vector for overall response Extrapolate to a wide variety of other behaviors: Eye movement in mammals Escape responses in crickets and cockroaches Flight orientation in insects Command neurons Model of habituation and sensitization Neuromodulation by 5-HT
Imitation
Copying another's behavior exactly to reach the same goal Capable of social traditions > culture?
why signal food location
Costs: Increases competition Signal production takes time and energy Potential benefits: Increasing number of foragers improves foraging success and/or decreases predation risk for individual Increases reproduction of relatives Food may allow long-term survival of group which increases chance of discovering sites in future (group selectionist?)
suprachiasmatic nucleus (SCN)
DIAGRAM Suprachiasmatic nucleus (SCN) - master clock in mammals, synchs all other body clocks < coupling of 10,000 neurons • Eclosion rhythms in Drosophila, time of eclosion normally constant across dark light cycle • Mutant strains identified and isolated per+ (short period, earlier each cycle), per(s) (later), per0 (no rhythm) • Encoded transcription factor • Genomic clock model built - negative/pos feedback, also regulate transcription of output genes • Lots of diff clock genes, feedback in nucleus transgenic mouse > clock gene promotor/flurorescent reporter > imaging of brain slice in vitro > rhythms in SCN DIAGRAM OF GENOMIC CLOCK MODEL output from "clock" gene Circadian Pacemaking in Cells and Circuits of the Suprachiasmatic Nucleus DIAGRAM A schematic view of the core molecular feedback loop that sits at the heart of the mammalian pacemaker. The definition of circadian time pivots around the activation of Per and Cry genes by Clock/Bmal1 heterodimers (acting at E‐box enhancer sequences), alternating with repression of the same genes by their protein products. Clock‐controlled output genes carrying E‐boxes are also subject to daily activation and repression, generating downstream transcriptional cascades that ultimately encode circadian cycles of physiology and behaviour.
sink fishing behaviour
DIAGRAM what controls feeding cycle? Sinking passively tentacles extended to fish Feeding inhibits swimming so sinks Exhaust food supply? Feeding stops so swimming resumes But upside down → tilts to swim upwards Swims upward, contract tentacle to feed Encounters new food source, inhibits swimming But right side up → tilts to drift downwards • Catches copepod, goes to manubrium/mouth • Mouthpiece moves towards tentacle with prey • Motorgiant axons conduct much faster for escape response - how? • Detect predator by hair cells- vibration (triggers intracellular EPSP) • Trigger AP in giant nerve ring (not inner nerve ring) • Induces bigger action potential, neurotransmitter release • Don't need hair cell structure • 2 diff behaviours by same nerves • BIGGER FOR PREDATOR • SWAMPS PACEMAKER AP • NT RELEASE Contact with object or predator Deflection of hair cells-mechanoreceptor on (60-80) tentacles Detect vibration in water by approaching predator Tentacles rapid conduction giant axon Ring coordinates subumbrellar myoepithelium (muscle) contraction via giant motor neurons Short chemical synaptic delay (amongst fastest in invertebrates) Aglantha anatomy, hair cells DIAGRAM hair cell stimulation elicits EPSPs in ring giant how can 2 diff behaviours be elicited by same nerves? ionic basis of slow swimming behaviour Slow rising and decaying EPSP of pacemaker on motor giants Activate low threshold ~-50 mV Ca2+ action potentials (spikes) Small amplitude 30 mV Depolarization: T-type Ca2+ channels, low threshold transient Repolarization fast V-sensitive K+ channels curtails AP height Slow propagation along motor giants > slow swimming Ca2+ AP fails to elicit faster Na+ spike due to low magnitude Fast rising and decaying EPSP of hair cells on motor giants Activate high threshold ~-33 mV Na+ action potentials (spikes) High amplitude 100 mV Fast propagation along motor giants fast swimming giant axons in escape behaviour Mollusca - long veined squid annelida - earthworm arthropoda - freshwater crayfish transducers > sensory pathway > integration (<rhythms) > effector pathway > effector muscles
Detecting tilt- statocysts
DIAGRAM • Statocysts involved in orientation • Subumbrellar - muscle sheet • Mesogloea - jelly-like material • Pacemaker, Action Potential travels round ring nerve, radial muscles, goes to motorgiants • Neurons 80microns in diameter (big), rapid contraction • Chemical synapses • Statolith rolls around and detects shift Mechanoreceptor of statocyst respond to setae deflection by gravitational action on statolith Output to ring giant axon > motor giant axon Signal routing as to coordinate subumbrellar myoepithelium contraction required directional swimming Statocysts output control myoepithelium independently asymmetric contraction and righting response
sensory receptors
DIAGRAM/TABLE chemosensory- gustatory
insect olfactory receptors
DIAGRAMS Many genes coding odorant receptors (341 in Tribolium flour beetle). Orco - highly conserved forms Heteromer with other Ors. 7 TM proteins used to be thought to be GPCRs. Orco/Or complexes act as Odorant-gated ion channel. role of G-proteins unclear. CO2receptors part of gustatory receptor family. Irs are ionotropic glutamate receptors may detect acids and aldehydes sensillum odorant-binding proteins (OBPs) bind pheromones and host odours OBPs can be extracted from antennae of some insects OBPs and CSPs have been reported in many insects similarity/dissimilarity between spp. predicting OBPs from genome databases DIAGRAM It is possible to use OBPs or CSPs to look at interactions with specific odorant molecules. This can use advanced chemical analysis techniques or ligand binding studies It may then be possible to make synthetic molecules to affect the responses and maybe manipulate behaviours
patch choice model
Decision - when is the optimal time to leave a patch? - example: bumblebee visiting flowers Currency - maximise profitability (E/T) Constraints time spent searching in patches and travelling between patches are independent foragers encounter patches sequentially perfect knowledge, i.e. energy gain in a patch and patch locations are known energy gain in patches shows diminishing return more time in patch, less gain after a while- diminishing returns due to patch depletion or prey evasion
Proposed combinatorial code for behavioural decision making.
Decision making trajectories Repeated recordings from several identified neurons in response to stimulus No unique set of neurons for behaviour subject to statistical and neuromodulator influences • proposed combinational code for behavioural decision making • if certain neurons fire you get certain behaviours • no unique set of neurons for behaviour • motor neurons recording in leech • same stimuli results in diff behaviours - degree of randomness goes into integration: motivation, rhythms, inhibition, hormones
optimality model elements
Decision variable - behavioural option, e.g. crack mussel or not Currency - must correlate with fitness (LRS) LRS = Lifetime Reproductive Success - often maximize rate of net energy intake (E/T) Constraints - intrinsic - limitations in ability (bill hardness) - tolerances (nutrition requirement) - extrinsic - imposed by environment (prey density) e.g. oystercatchers again constraints, extrinsic: large muscles only- bill damage Among free-living oystercatchers the prevalence of bill damage was correlated with mean cockle size near the capture site.
Types of food location signals
Discoverer broadcasts signal from resources and receivers recruit to the site Discoverer goes to receivers (often at nest or colony) communicates discovery and then leads receivers to site Discoverer goes to receivers and provides directional information about the site e.g. dance of honeybee Apis bees waggle includes sound in enclosed hives, visual signal in open dance angle indicates direction can perform the dance on the horizontal plane, where direction information with respect to the sun is easy to interpret can ALSO translate this to the vertical and the receivers can convert it back to a horizontal direction dance duration indicates distance direction of straight run correlates w dist to food source dance speed/rate indicates quality dances can also signal new hive choice Evolution: Meliponini - stingless bees Apini - honeybees (dances w dist and directional info OR just distance) Bombini - bumblebees dance w/o either info Euglossini - orchid bees (loss of sociality & dances)
feeding in a group
Distribution of resources can lead to social interaction Intentional or not? - sociality or incidental proximity? Sociality may increase or decrease foraging success degree of proximity with neighbours is unlikely to be a matter of chance social aggravation vs. territoriality not mutually exclusive e.g. gannets
Why don't animals cheat in fights/why fight conventionally
ESS: evolutionary stable strategy Strategy: the behavioural response of an individual ESS: a strategy which, if adopted by all members of a population, cannot be invaded by an alternative strategy The ESS is found using game theory. Game theory is invoked when the consequences of a behaviour depend on what others are doing: i.e. it is frequency dependent e.g. of freq dependence Perissodus microlepis If the majority of scale-eating attacks come from the left, a prey-fish will be more vigilant on it's left side and left-jawed fishes (that attack on the right) will be at an advantage. They will leave more offspring, who will have left-jaws, but over time, the prey-fish will expect an attack on the right, and then the right-jawed fishes will have the advantage. Measured over 10 years, you can see how the frequency changes over time of left and right jaws, and how how well your phenotype does depends on what everyone else in the population is doing, or what the frequency of different phenotypes are in your population.
development and genetic determinism
Easy to demonstrate interactions between genotype and environment in behaviour e.g. maze learning in different strains of mice, effects of in utero hormonal environment Male-typical behaviour (aggression) in mice depends on the hormonal environment in utero. Males that were gestated between 2 other male pups had lower levels of circulating female hormone, estradiol, in the amniotic fluid around them. They also absorbed more testosterone from their neighbours. The males gestated between 2 other male pups, were significantly more aggressive than males gestated between two females.
neurobiology/no. of neurons
Electrical signalling within a unicellular organism Swimming and avoidance in Paramecium No neurons, ion channels, membrane and intracellular signals Chemical signalling within and between cells Response to light in barnacles and horseshoe crabs ~1000 neurons Bees ~1,000,000 neurons Complicated Nerve circuitry Coordination of swimming in Jelly fish and leeches ~10,000 neurons Modulation of neuronal activity Sea slugs and leeches ~10-20,000 neurons
eusociality- why don't workers reproduce?
Eusociality probably evolved in response to ecological conditions that made dispersal and independent reproduction difficult This favoured the formation of defended permanent nests and the helping of parents to reproduce Inclusive fitness and kin selection allowed for the maintenance of non-reproductive workers... kin selection and inclusive fitness diploid queen -> daughter r=0.5 diploid sisters r=0.75 (more closely related than offspring) haploid drone -> haploid gametes drone/daughter r=1 Parental manipulation -reproductive suppression Bullying by queen and other group members increases stress hormones and suppresses reproduction in helpers. e.g. banded mongoose Works in societies classified as cooperatively breeding as well as eusocial animals like the naked mole rat. Anarchistic honeybees and worker policing Worker bees can increase their own reproductive success by laying their own eggs (haploid) Other workers sense this is not a queen egg and eat it, forming a police force that protects the stability of the hive This form of cheating occurs in low levels in the wild More common when queen mates multiply
How to answer behavioural questions
Experiment manipulate the system and see if you're right Observation observe outcomes in existing situations Comparative approach compare behaviour within species in different situations compare behaviour between species that differ in relevant ways Modelling explore systems theoretically to test assumptions and predictions e.g. EXPERIMENTAL/MECHANISM rats and feeding behaviour suspected that the feedback mechanism occurred in the hypothalamus knock out the regulation (destroy that part of the brain) of feeding behaviour and rats are less likely to moderate their food intake and become hyperphagic (eats too much) the rats that had their hypothalamus operated on lost their appetite at first but then consumption increased rapidly and stabilised at a much higher level than rats with a brain that had been operated on but nothing had been ablated e.g. EXPERIMENTAL/FUNCTION Why do some magpies lay 4 eggs and some lay 8 eggs? Why don't they all lay lots of eggs every time they nest? found magpie nests that naturally had small clutch sizes and ones that had large clutch sizes and then manipulated the numbers of hatched young in the nest. They showed experimentally that magpie pairs that had small clutch sizes were less able to fledge large numbers of chicks, and those that had naturally large clutch sizes were better at fledgling large numbers of chicks. So the magpies were laying apparently optimal clutch sizes, sizes that they had a good chance of feeding well and fledging a reasonable proportion of. Therefore, the function of laying a particular clutch size appears to be to ensure survival of most of those young produced. e.g. COMPARATIVE/FUNCTION Exploring differences between individuals of the same species. Ground squirrels live in groups and a preyed upon by various animals like foxes and birds of prey. There is often one individual that spots the predator before the others, and it can give a sharp alarm call but giving that call delays its own escape response. 'Why do individual Belding's ground squirrels sometimes give alarm calls and sometimes they don't?' They looked at the genetic makeup of the groups of ground squirrels and found that they are most likely to call if there are descendent kin, like offspring in the area, in order to enhance their survival. Modelling: explore systems theoretically to test assumptions and predictions these often involve very simple 'rules' e.g. 'quit when time spent on activity = x or when energy expended = y'
mammals
Extensive cephalisation. Especially primates. Learning/training. Reasoning. Strategy, e.g. hunting. Emmotions. Curiosity. Play
range of receptor systems and modalities
Exteroceptors - external environment: spatial (vision), chemical (olfaction), physical (touch) Interoceptors - internal environment homeostasis (osmolarity, pO2, energy, temperature) Proprioceptors - position in space posture (muscle spindles, vestibular system) Information about internal & external environment essential to organism survival Integrated for appropriate physiological response Integrated for appropriate behavioural response
Jelly fish: Aglantha digitale
Feeding behaviour 1. sinking passively tentacles extended to fish 2. bottom of feeding cycle, righting behaviour starts to swim 3. swims upward, contract tentacle to feed 4. cycle restarts escape swimming Aglantha anatomy, umbrella DIAGRAM feeding swimming behaviour nerve net Giant inner nerve ring innervated by pacemaker neurons Pulses every 2 seconds Ring coordinates subumbrellar myoepithelium (muscle) contraction via 8 radial symmetrical giant motor neurons giant as 30-40 µM diameter rapid AP conduction Form chemical synapses with muscle Subumbrella contracts expels water to propels medusa Followed by relaxation before cycle restarts Outward expansion force by mesogloea non-living gel 85% water muscle contracts (myoepithelium contracts) CNS and pacemaker activity MG motor giant axon MGR motor giant rootlets P pacemaker system R relay system C carrier system RG ring giant axon TS tentacle slow TG tentacle giant axon -fast H hair cells Arrows show output direction DIAGRAM
making decisions
Finding a place to live Finding food Social behaviour Mating Communication The way decisions can be made depends partly on the characteristics of the environment. But you do not have to stay in the environment you were born in Aphids - how do female aphids decide whether to share a leaf with others or move to a new leaf on their own? How do they select the size of the leaf they settle on? Arctic hares - why would you stay in such an inhospitable environment? Why don't they migrate south for the winter like other arctic animals do? Great tits - why do they live in the kinds of forests they are found in? Isn't one type of forest as good as another?
vertebrates
First appeared in fish about 520 million years ago Autonomic vs somatic system Autonomic split into sympathetic and parasympathetic somatic=muscles DIAGRAMS? vertebrate evolution- brain becoming enlarged, most obvious in cerebrum
VNO
Flehman's position in horses increases access of scents to vomeronasal (VNO or Jacobson's) organ (curl lips) VNO is an auxiliary olfactory sense organ found in many animals. The VNO is the first stage of the accessory olfactory system and contains sensory neurons that detect chemical stimuli. The axons from these neurons project to the accessory olfactory bulb, which targets the amygdala. The vomeronasal organ is mainly used to detect pheromones. The neurons in the VNO express receptors from three families which are distinct from each other and from the large family of receptors in the main olfactory system. snake tongue/VNO sample the air with their tongues and then wipe the sample in Jacobson's organs which are chemosensory pits in the roof of the buccal cavity
adaption to light in barnacles
Given constant release of histamine in bright light then why not fatigue adaptation Modulation of release and recycling maintain an apparent infinite histamine supply As ambient light increases A B C the photoreceptor depolarizes however due to adaptation the I-cell can still hyperpolarize and remains capable of responding to changes in light Maintain high gain and sensitivity, necessity for many sensory systems response shifts
consequences of anisogamy
Greater variance in male reproductive success in Elephant seal Female dispersion governed mainly by the distribution of resources, male dispersion by the distribution of females e.g. extreme resource defence, lek, harem territory, male matrix (group of females move between male territories), sublease territory (females separated within male territory), pair territory
'types' of learning
Habituation Classical conditioning AKA: conditioned reflex Type 1, respondent or Pavlovian conditioning Operant conditioning AKA: conditioned reflex Type 2, instrumental conditioning or 'trial-and-error' learning Imprinting Latent learning Insight learning
domestication of social cognition
Hare, Brown, Williamson, and Tomasello (2002) Object choice tasks GPT = Gaze, point, tap GP = Gaze, point P = Point C = Control (no cue) Dogs found more food than wolves in the visual cue conditions No difference between puppies that had lived with human families and those who were litter-reared
Crows (corvids)
High EQ (4) solve puzzles
Matthews' sun-arc hypothesis
How do some animals like pigeons, use the sun to navigate? Matthews figured that birds must track the movement of the sun throughout the day. So birds that need to fly in a certain direction can extrapolate the highest point of the sun in the sky and then compare that highest point with where they need to go and decide which direction to fly in not proven but lots of other spp. use sun's azimuth (position relative to themselves) to navigate
Limulus: lateral inhibition (horseshoe crab)
ID/detection of movement- mating? depending upon mutual inhibition of neighbours lateral inhibition: -edge detection enhancement of contrast -removes redundant information -not just intensity but spatial pattern of illumination -not just light: also tactile/auditory -universal in vertebrates -allow detection of small differences in modality against background (effect of time of day, weather, season- compare to adaption) • Lateral inhibition - capacity of excited neuron to reduce activity of its neighbours • Disables spreading of action potentials from excited neurons to neighbouring neurons in lateral direction; creates contrast in stimulation that allows increased sensory perception • Increases contrast/sharpness in visual response • In dark, small light stimulus will enhance diff photoreceptors (rods) and rods in centre of stimulus will transduce "light" signal to brain, whereas diff rods on outside of stimulus will send "dark" signal to brain due to lateral inhibition from horizontal cells • Mate seeking in dark (horseshoe crab), beach white sand • Concrete slabs that look like females - probability of successful "hit" real female • Diff sizes (bigger, easier to find) • Contrasts mean more hits transducers > sensory pathway > integration > effector pathway > effector muscles
when to be polygamous?
Ideal free theory: the polygyny threshold model Polyandry and sex role reversal Switching between mating systems Social versus covert mating systems: extra-pair copulations Orians-Verner-Willson model polygyny threshold model DIAGRAM Prothonotary warbler Poly/mono depending on no. of territories/no. of nest sites per territory more nest sites- more likely to be polygynous Ideal free theory: the polygyny threshold model Polyandry and sex role reversal African jacana (Actophilornis africanus)
assumptions of optimality theory models
Identify the problem/s to be solved (decision variable) Choose the right currency (currency variable) Identify the available alternative solutions and constraints (constraint variable) Quantify the costs and benefits accruing from the available alternatives Assume appropriate genetic variation has arisen How evolution shapes decision-making in the context of the problems of survival and reproduction set by the animal's environment e.g. the problems of: - prioritising goals - finding a place to live - finding food - communicating - social behaviour Can be v difficult to determine what problem an animal is trying to solve w a particular behaviour All assumptions limited by what we can hope to know about our organism Last one concerned w adaptiveness of organism- does its genotype allow it to do what we are assuming it's trying to do OPTIMALITY CURVE DIAGRAM
the lek paradox
In lekking species, males only provide sperm. Therefore, only indirect benefits are possible. If males differ in genetic quality, then females should always prefer the highest quality male. Over time, such intense selection will deplete and possibly eliminate genetic variation. what do females gain by choosing? solution: Genetic variation must persist for ornamental traits and genetic quality Ornament expression depends on good condition. Only males in good condition are able to fully express ornament, condition can fluctuate year to year. Condition is likely influenced by many genes. Consequently, deleterious mutations constantly replenish genetic variation.
Sender-receiver arms races and receiver psychology
Incidentally or ancestrally useful information likely to lead to sender-receiver arms race -receiver attempting to 'read' the sender to its own advantage -sender attempting both to avoid being 'read' to its disadvantage, but at the same time manipulate the receiver Leads to elaboration of traits into distinctive signals to manipulate receivers, and enhanced discrimination by receivers to read them accurately -ritualisation E.g. ritualisation of courtship 'feeding' display in phasianids (pheasants) Elements of signal design: strategic design - what the signal has evolved to communicate (e.g. stamina and good health) tactical design - maximise efficacy in relation to: (a) transmission and detectability in the signaller's environment and (b) exploitation by the receiver's CNS and psychological 'landscape' (receiver psychology) Components of receiver psychology: detectability - while signal detectability is likely to be heavily shaped by the environment, it also depends on thresholds of discrimination and information integration in the receiver's CNS discriminability - rules for recognising stimuli making up a signal as belonging to some discrete category memorability - effective responses to signals often depend on learning: striking and memorable stimuli are likely to be favoured Implications of receiver psychology: Unintended receivers Eavesdroppers and audience effects Multicomponent displays to focus attention e.g. Vogelkop bowerbird Widespread common features of warning colouration and mimicry - based on memorability? e.g. hoverflies (Syrphidae) mimicking Hymenopteran wasps
Using the Earth's magnetic field
Inclination (angle with the horizontal) Declination (angle between magnetic and true north) e.g. magnetic compass in robins migrate spring robins have gone further south (come in from the continent) Helmholtz coil that can change the local magnetic field follow the North south migratory paths from the altered magnetic field, not the actual one e.g. earth's magnetic field as a backup cue in homing pigeons Pigeons that had small magnets attached to them were very bad at navigating on cloudy days compared with control pigeons who only had small brass weights attached as a navigational map in homing pigeons? disorientating effects of magnetic anomalies if pigeons fly over a magnetic anomaly they go in all directions, but once past it they can usually recover, this indicates it more of a cue than a map, because they should be able to use it as a landmark and go around it.
Adaptive decision-making and migration
Information and calculated migration Is there a genetic basis for migratory behaviour? Intraspecific variation and game theory models
pain and withdrawal reflex
Input:Transduction (external stimulus to bio signal) Encoding (amplitude modulation- appropriate response size) Transmission (action potential) Interpretation (computation- forwards/backwards, appropriate response direction) Output: Response (effector, motility) Association, learning, adaptation injury > peripheral nociceptors > peripheral nerve > dorsal root ganglion > dorsal horn > spinal cord > descending/ascending pathway > brain > PAIN
Personality
Inter-individual differences in behaviour were dismissed as 'noise' around a mean response Now some of these differences are termed 'personality' Evidence from more than 60 species across animal kingdom Do not confuse this definition with the common usage of 'personality' Personality: behavioural responses that differ between individuals, but are consistent across time and contexts within an individual behavioural syndromes diagram AKA 'coping styles' or 'temperaments' Correlated suites of behavioural traits Shy often correlates with low aggression and subordinate behaviour in social animals Bold often correlates with high aggression and dominance in social animals Evolutionary puzzle: How can multiple personality types co-exist in a population? Shy: Reduce risk Slow explorers Slow to leave refuge Neophobic Can discover hidden resources/last to access resources
honesty and handicaps - intersexual selection
Intersexual selection - heritability of underlying fitness traits penalising females choosing males dishonestly signalling high quality Developmental stability - fluctuating asymmetry e.g. male barn swallow w ornamental tail streamers elongated- fewer days before mating Arms races driving honesty push up cost of signalling so that high cost signals can be borne only by high quality individuals Therefore, pays high quality individuals to possess high cost signals to indicate quality - the 'handicap principle' Zahavi's handicap principle: Exaggerated secondary sexual traits are detrimental to survival Males with the largest traits must be high quality in order to survive them Females secure good genes by mating with these males Adaptationist in contrast to Fisherian selection, but what is the mechanism? Immunocompetence Handicap model might work by the endocrine system both producing secondary sexual characters and influencing immune system function, which determines how well parasites can be managed. The parasites in turn attack the secondary sexual characters DIAGRAM red junglefowl Lymphocytes, or white blood cells, increase in numbers when the animal is actively fighting off an infection, they decrease in response to testosterone circulating through the body. Testosterone is responsible for the production of the comb on top of the head. There is a relationship between testosterone, comb length and amount of circulating white blood cells carotenoid-based secondary sexual characters as indicators of immunocompetence Three-spine stickleback male body colouration Zebra finch male beak colouration House finch male plumage RED=more attractive dietary carotenoids - tradeoff between immune defence (like antioxidants, catalysts or irreversibly depleted) and ornament
honesty and handicaps - intrasexual selection
Intrasexual selection - signalling competitive ability; assessor-cheat arms races driving honesty through probing and punishment of dishonest signallers selection pressures driving honesty? e.g. assessor-cheat arm races Intersexual selection - heritability of underlying fitness traits penalising females choosing males dishonestly signalling high quality Males were silenced and a high (small body size) or a low pitched (large body size) croak was played. The males with the high pitched calls played got the highest number of attacks but there is still an element of physical assessment from tactile and visual stimuli, so that smaller males generally got attacked more overall e.g. Assessment of competitive ability ('resource holding potential') in male cichlids If there is no difference between weights of competitors (0), then contests take longer to settle and more aggressive behaviours employed as they are closely matched in competitive ability. Status badges e.g. harris sparrows black patch house sparrows - higher variance in badge size reduced aggression in groups, and more within-moult aggression led to larger mean badge sizes also linked to age (old male is a good male) escalation of aggression in red deer chance at every stage for the weaker male to back down and retreat
Semiochemicals in chemical ecology
Intraspecific: Pheromones - induce specific reaction such as special behaviour or developmental process. Interspecific: Allelochemicals - Allomones : benefit the originator but not the receiver. Kairomones : benefit the receiver but not the emitter. Synomones : benefit both parties. PHEROMONES: sex, alarm, aggregation, oviposition ALLOCHEMS: kairomones (host location), allomones (antifeedants), synomones
neurobiology in inverts/verts
Ion channels -Types and forms Neurotransmitters -Chemical signalling within and between cells Nerve circuitries -Reflex arc -Pacemakers -CPGs -Command neurons Neuromodulation Transducers Effectors -Muscles -Exocrine and endocrine secretion
sun compass in captive starlings
Kramer deflect the light from the sun into the cages of captive starlings, to make them think the sun was at an angle to them 90 degrees different to reality the starlings flew at an angle 90 deg from the true path they were meant to fly
eavesdropping
Male frogs producing chuck calls during courtship also attract the Fringe-lipped bat, a predator The female frogs are attracted to the males with the most complex calls, that have the most 'chuck' notes. The bats are also attracted to the most complex calls, they will find more males and more females gathered around the most attractive males and increase their chances of successful predation.
Ovarian follicle: source of estradiol
LH > FSH > androgen > E2 > behaviour+reproductive tract DIAGRAM • Androgens precursors to estrogens • Androgens > estradiol • Estrogen then used in behaviour/reproductive tract • E1 estrogen, E2 estradiol • Ovulation when E2 reaches peak, signal to brain
Chemotaxis in Paramecium
Locating and maintaining an optimum pH If a source of Carbon dioxide is added to their tank of water, the Paramecuim will move to where the pH s the correct one for survival. They are responding to directional signals from a chemical source, so this is known as chemotaxis
optimal foraging behaviour
Logic - natural selection generates behavioural responses that maximise fitness by balancing benefits against costs - "evolutionary economics" Advantages - makes assumptions explicit - generates testable predictions - suggests new hypotheses if model doesn't fit Criticisms - behaviour may not always be optimal
integrating cues
Magnetic cues and the sun compass in pigeons Young pigeons that have seen the sun during rearing require it to orientate correctly on first release - disorientated when overcast where experienced birds aren't Bar magnets disrupt the ability of first flight pigeons to use the sun compass (experienced birds can use the sun and magnetic field independently) Young pigeons reared with no view of the sun orientate correctly on first release even in overcast conditions Use of the sun compass appears to be learned e.g.: clock-shifting experiments show that young pigeons have to learn the relationship between the sun's position and time of day The sun compass thus seems to be a derivative compass that requires initial calibration, probably using the magnetic field magnetic compass- primary cue sun compass calibrated from it
chemical weapons
Many target fast signalling proteins in the nervous system leading to rapid effect. Ion channels and receptors in neurotransmission: Potassium channels - (re)polarization Voltage-gated sodium channels - conduction Voltage-gated calcium channels - neurotransmitter release Nicotinic acetylcholine receptors - synaptic transmission (including NMJ) Ionotropic glutamate receptors - synaptic transmission (NMJ in arthropods) neurotoxins- peptides usually quite small with multiple disulphide bridges - "three-fingered toxins" and "cysteine knot peptides" Target all major neurotransmission ion channels: Voltage-gated sodium channels - loss or gain of function Loss of function > inhibits action potentials > flaccid paralysis Gain of function > prolonged or more action potentials > rigid paralysis Voltage-gated potassium channels - loss of function > prolonged action potentials > rigid paralysis Voltage-gated calcium channels - loss of function > inhibits neurotransmitter release and thus synaptic transmission > flaccid paralysis Nicotinic acetylcholine receptors - loss of function > inhibits synaptic transmission (esp. at NMJ) > flaccid paralysis e.g. sydney funnel web δ-atracotoxins 41 aa peptides with 4 disulphide bridges Delay VGSC inactivation like ATX-II e.g. α-bungarotoxin - Banded krait 62 aa peptide with 4 disulphide bridges Inhibits ACh binding to nAChR non-peptide neurotoxins Low molecular weight, usually <1000 Da. Target some major neurotransmission ion channels: Voltage-gated sodium channels - loss of function > inhibits action potentials > flaccid paralysis Voltage-gated calcium channels - loss of function > inhibits neurotransmitter release and thus synaptic transmission > flaccid paralysis Nicotinic acetylcholine receptors - loss of function > inhibits synaptic transmission > flaccid paralysis Ionotropic glutamate receptors - loss of function > inhibits synaptic transmission (esp. at arthropod NMJ) > flaccid paralysis e.g. blue ringed octopus tetrodotoxin blocks pore of voltage-gated sodium channel e.g. Philanthus triangulum wasp Catches and paralyses honeybee in flight Puts paralysed bee in a hole Lays eggs on bee Eggs hatch on fresh food Philanthotoxin-433 blocks nAChR pore - use-dependent Wasp blocks core region of nicotinic acetylcholine receptors
when to be monogamous
Mate-guarding hypothesis - males remain with fertilised mates to prevent access by other males e.g. monogamy in clown shrimp (Receptive females are widely dispersed and rare) Female-enforced monogamy - females aggressively deter males from approaching other females e.g. burying beetle (Females are aggressive to members of their own sex intruding into the site where they male and female have just buried a food ball to lay eggs into. When finished, the male climbs to a perch high up and releases a sex pheromone. The female does not want another female to be attracted and lay extra eggs in the food ball that will compete with her larvae when they hatch, so she shoves the male off his perch and stops him releasing the signal. If the female is restrained by researchers, the male signals for longer) Parental care hypothesis - in some environments it may pay males to help females rear offspring rather than go off and sire more Mate-assistance monogamy e.g. White's seahorse (durable relationship between mated pairs, greet every morning, forage separately, male accepts several clutches from his female as he's unlikely to find another mate-ready female as soon as one clutch is completed)
mating systems and parental care
Mating systems are determined by ecological factors, so is parental care Parental care ranges from none, to uniparental to biparental care. Uniparental care - mammals Biparental care - birds Understanding these systems comes through a cost-benefit analysis Life history traits of the species play a big part, but ultimately, life history traits are determined by what the environment a species lives in can bear. So, longevity plays a part, but longevity is partly determined by the environment, how stable it is and how much food is available.
mating systems- polyandry
Mating with multiple males to ensure good genes or genetic complementarity Mating with more than one male to secure additional parental care or reduce infanticide Constraints on incubatable clutch size, so that female reproductive success is increased with more partners Female competition for access to males can lead to sex role reversal in appearance and behaviour e.g. pseudoscorpion more nymphs if more males to mate with Sex role reversal e.g. red-necked phalarope spotted sandpipers females are often larger and more brightly coloured than males, and females fight for the 'best' parental males males still mate guard in this species and even though it is female dominant, there still sexual conflict and in order for the system to remain stable, females are required to provide males with eggs that are predominantly genetically theirs or they will not incubate them
Are monkeys logical?
McGonigle & Chalmers (1977) squirrel monkeys value transfer reinforcement history matters, e.g. certain colours have high value/are always rewarded, some never rewarded could transfer to diff colours and their values (infer one worth more than another) why? social ranking? Paz-y-Mino et al. (2004) pinyon jays Social groups of birds: Letter group (A > B), Number group (1 > 2). Experimental group: observes member of own group losing Control group: observes member of other group losing Test observer (3) against member of other group Experimental group: show more submissive behaviour than control group social influence Social facilitation Increase in behavior due to presence of others performing that behaviour (e.g., humans yawning, migration of sea turtle hatchlings, herd behaviour) Stimulus and local enhancement Increase in tendency to interact with object (stimulus) or approach location (local) because of presence/actions of others. Affordance learning Learning about what can be done with objects or the environment - not necessary to have observed from another. Learning that results from the behaviour of other animals Quicker and less risky than trial and error learning
Tinbergen's 4 questions
Mechanism answers in terms of internal and external causal factors (anatomical/physiological mechanisms, external cues). Birds sing in spring because increasing daylength triggers hormonal changes in the body (neuroscience - Pavlov) Development answers in terms of developmental processes (maturation, learning). Birds sing in spring because they learned to from their fathers (experimental psychology - WD Hamilton: the evolution of altruism and spite and the maintenance of sex ratios) (ethology) Function answers in terms of the reproductive (adaptive) value of the behaviour. Birds sing in spring in order to attract mates (behavioural psychology - Konrad Lorenz: ethologist who studied geese with Tinbergen. Imprinting behaviour and development and, to an extent, mechanistic questions) Evolution answers in terms of evolutionary history. Birds sing in spring because singing in spring was favoured in their ancestors (evolutionary psychology - Tinbergen)
learning and intelligence - The problem of comparative measures
Mechanosensory constraints on designing equivalent tests across species species biases in: manipulative skills, memory specialisation, reward priorities... Adaptive specialisation in learning Tests are necessarily selective rather than global Macphail's 'null hypothesis' (1982) - all non-human vertebrates are of equal intelligence. While they are specialised in lots of different ways, all share the same fundamental abilities to learn i.e.: the principles of associative learning are the same across taxa sometimes compare spp. whose abilities aren't equal e.g. Hyenas are better at solving a problem that requires cooperation to obtain food than chimpanzees are Non-human primates are not obligated to hunt, only some will Non-human primates that hunt often target smaller, harmless prey Hyenas target large, dangerous prey that require a coordinated attack Hyenas are social carnivores they do better in a cooperative test of pulling on a rope to obtain food with two animals cooperating than chimpanzees do. This is because the rope-pull action is similar to the move they use when hunting to pull down large prey, and chimps are much less cooperative when hunting, it is usually just the dominant male who subdues and kills the prey. Shift away from measuring 'ability' in basic learning tasks to comparing 'higher level' aspects i.e.: the ability to generalise learned rules to different tasks and contexts: learning sets/concept formation Or: to perceive the solution to a problem through a spontaneous novel reorganisation of existing experience: Insight
observational conditioning
Mineka and Cook (1988) Monkeys fear of snakes Laboratory-reared monkeys observed a wild-reared monkey's reactions to a real snake (boa constrictor), a model snake, and a toy snake After the observation, the observer monkeys displayed more avoidance and fear behaviors than before the observation. CS (snake) + US (model's fear response) > UR (fear) CS > UR
Mating systems
Monogamy Polygyny - polygamy Polyandry - polygamy Polygynandry - polygamy Promiscuity - promiscuity -gamy: gamete -andry: male -gyny: female
Quantitative trait loci
Much current work aims to locate and estimate the effect of 'quantitative trait loci'(QTLs) Use F2 or backcross individuals Genotype each individual at multiple genetic markers Construct linkage map Measure association between markers and trait Quantitative trait locus (QTL) analysis is a statistical method that links two types of information—phenotypic data (trait measurements) and genotypic data (usually molecular markers)—in an attempt to explain the genetic basis of variation in complex traits E.g. aggression in mice need continuous polygenic trait, start by mating individuals either ends of bel-shaped dist for that trait QTL mapping requires parental strains that differ genetically for the trait, such as lines created by divergent artificial selection. The parental lines are crossed to create F1 individuals, which are then crossed among themselves to create an F2, or crossed to one of the parent lines to create backcross progeny. Both of these crosses produce individuals or strains that contain different fractions of the genome of each parental line. The phenotype for each of these recombinant individuals or lines is assessed, as is the genotype of markers that vary between the parental strains. Statistical techniques such as composite interval mapping evaluate the probability that a marker or an interval between two markers is associated with a QTL affecting the trait, while simultaneously controlling for the effects of other markers on the trait. The results of such an analysis are presented as a plot of the test statistic against the chromosomal map position, in recombination units (cM centimorgans). Positions of the markers are shown as triangles. The horizontal line marks the significance threshold. Likelihood ratios above this line are formally significant, with the best estimate of QTL positions given by the chromosomal position corresponding to the highest significant likelihood ratio. Thus, the figure shows five possible QTL, with the best-supported QTLs around 10 and 60 cM
nerve conduction
Nerves unmyelinated NCV ring giant axon 2.6 m.s -1 NCV motor giant axon Slow feeding swimming 0.4 m.s -1 Fast escape swimming 3 m.s -1 How can same axon conduct at different speeds for different behaviours? Slow swimming Pacemaker drives MG via EPSP Coordinated Swimming and synchronisation of MG firing mediated by rootlets system Gap junctional coupling within rootlet allow synchronisation Act like "ring"
navigation
Orientation - taking up a particular bearing with respect to the current position or a 'landmark' - compass mechanisms Navigation - finding the way from the present position to a given destination - navigational maps Kineses - orientation towards a location without reference to any directional stimulus altered rate and/or direction of movement in relation to the strength of a non-directional stimulus NON-DIRECTIONAL Taxes - orientation (usually towards or away) with respect to a directional stimulus DIRECTIONAL
Avoidance and the single cell Electrical signalling and ion channels
Paramecium caudatum Phylum Ciliophora Single cell Protozoa Exhibit complex behaviours Feed, motility, escape predation and reproduce Jennings early 20thC thought conscious Electrical activity explains behaviour Universal communication mechanisms avoidance behaviour/electrical signalling Physical Chemical? Temperature? pH? Light? Salinity ciliary movements in locomotion > direction of locomotion < propulsion of water effective stroke < recovery stroke > metachronal wave measure membrane potential (Vm) responses Mechanosensitive receptor potentials transduction and amplitude modulation Control ciliary movement w calcium + for anterior stimulation, more calcium - for posterior stimulation, decease in calcium calcium moves in, depolarisation increase in calcium to speed up ?
how much care to provide?
Parental investment: 'any investment by the parent in an individual offspring that increases the offspring's chance of surviving at the cost of the parent's ability to invest in other offspring.' Costs of parental care include - reduced future survival - reduced mating opportunities e.g. willow tit parental care decrease adult survival
Quantitative genetics
Partitions genetic and environmental effects • Assumptions: - each locus contributes additively to the trait - environmental effects are independent • Definitions: p = phenotypic value g = genotypic value e = environmental effect p = g + e
Perceptual worlds
Perceptual abilities vary between species The world you experience is due to the processing ability of your brain This is important when researching animal behaviour
Evolution of display: hawks vs. doves
Possible behaviors: Display Fight but risk injury Retreat • Possible strategies: Hawk: fight until injured or opponent retreats Dove: display initially but retreat if opponent attacks (display takes a long time) DIAGRAMS
modelling foraging behaviour
Prey profitability: calories vs. handling time = (Energy/Time) Model the profitability of different prey items Consider real life... Test the model against reality e.g. oystercatcher measured the mussels available on the shoreline and the mussels the birds selected why not go for most common type? or biggest? biggest are tough and hard to pry open because they are also coated in barnacles. Might be a waste of time? Also, there is evidence that the oystercatchers could damage their bills by tackling prey that is too hard, and that could lead to starvation. feed on v specific type- big enough for a decent meal but small enough to open is it optimal foraging?
transduction
Process of converting modality into a biological signal Modality Physical Pressure, osmolality, vibration Chemical: pH, salinity, O2, CO2, Electromagnetic: light, heat, magnetism, electrical Transducer: protein Can be ion channel Direct e.g. mechanotransduction Modified GPCR Indirect e.g. rhodoposin and photoreception
How to study a behaviour
Proximate causes (how questions) Ultimate causes (why questions) e.g. monogamy in prairie voles most voles polygynous proximate: receptor for vasopressin is coded for by avpr1a. There is a different version of this gene in prairie voles It might increase receptors in the brain. Researchers inserted extra copies of the prairie vole avpr1a gene into the ventral palladium (VP) of test voles and they spent more time with their partners than strangers ultimate: How is the behaviour influenced by natural selection, i.e. related to reproductive success? Females could mate with monogamous males to reduce infanticide, subsequent offspring survive better with two parents. What is the evolutionary origin of the behaviour? Polygynous ancestors gave rise to monogamous species, dependent on selective pressures. Look at genetic relatedness between lots of vole species using the comparative method and compare the older species and their mating systems with the more derived or younger species.
signals as handicaps
Qualifying handicaps Condition-dependent handicaps Revealing handicaps Strategic choice handicaps
habitat associations
Random settlement and differential mortality? Selective choice of habitat? Heritability of adaptive preferences Choice associated with appropriate adaptive 'skills' Choice leading to increased reproductive success
who benefits from communication
Signals should become more obvious when there is chance that they will cost either the sender or the receiver
Gill withdrawal reflex habituation
Repeated stimulation reduced response Reduction in glutamate exocytosis Homosynaptic depression (HSD) Habituation
Sexual selection
Reproductive advantage through competition to mate
Natural selection
Reproductive advantage through competition to survive
Maturation and behavioural development
Salmon embryo is adapted to it's environment, it is not an imperfect adult waiting to happen progressive wiring-up of the neural connections as the embryo develops that shapes the animal's behavioural capabilities. At first movements are totally muscular in origin, they happen before the nervous system has fully formed. As neurons are formed the embryo is able to flex it's body Chicks improve pecking accuracy If you hood them so that their vision is slightly deflected 7 degrees by a small mirror, they still improve their aim, but it is skewed by the action of the hood (the environment) on their visual information. This shows they are integrating environmental feedback from their visual system into their development of their feeding behaviour. Because they are never getting any food reward with this set-up, this demonstrates that it is a maturation of ability rather than practice-based learning. effect of practise on attack behaviour (Sepia) slight difference between attacking a prey item and succeeding, and attacking, but not getting the environmental feedback of getting a meal. 'Latency to attack' means the time it took for them to initiate an attack, so a longer time is a worse attack, they got faster quickly when they were not rewarded or they were really hungry because they had more incentive to try again, but all types of 'training' improved with practice
sun compass and time compensation in homing pigeons
Schmidt-Koenig If you are using the sun to navigate, you must also have an idea of what time of day it is birds were clock-shifted by six hours, which has the same effect as deflecting the light by 90 degrees only works on sunny days, on cloudy days the birds navigated as normal, which shows that pigeons have at least one more navigational mechanism up their sleeve
Cat human communication
Schötz and van de Weijer (2014) Human's ability to classify meows (food related and vet related) Accuracy was above chance (65%), humans who reported experience with cats (70%) were better than inexperienced humans (54%) Cats use different intonation patterns
Aplysia learning, memory and behaviour
Simple <20,000 neurons <100 involved in simple behaviours Cell easy to identify, record, label and revisit Large mRNA to make cDNA library Stereotypical behaviours, topologically mapped Gill withdrawal reflex behaviour modified by three different forms of learning: habituation, sensitization, and classical conditioning Short and long term memories Strengthened by repetition Learning and behavioural changes occurs through changes in synaptic strength and plasticity Mantle-covered gill used for respiration Siphon used of expelling water and waste Gill withdrawal occurs when siphon is touched Defensive mechanism
somatosensory behaviour in leech
Semi-intact preparation (skin with attached ganglia) to record and identify of mechano-sensory neurones Topologically and functionally typical Identified neurons T- touch, 6 of (3 in each ganglion) P-pressure, 4 of (2 in each ganglion) N-noxious, 4 of (2 in each ganglion) Determined by excitation and ablation outline-motor neurons ~20 per ganglia Inhibitory and excitatory Determined by excitation and ablation • One muscle (dorsal or ventral) contracts, the other relaxes - alternating behaviour • One excited, one inhibited • Stimulate dorsal side, dorsal excitation, contract and vice versa • Interneuron important • Animal move in opp direction of touch • Shortening - s command neuron, connects ganglia • Sensory - Touch/pressure/noxious - slow->fast, more prolonged, maybe multiple Aps T-cells required for light touch habituation, S-cell for Sensitization Subscript indicates number of neurons, C interneuron, L motorneuron DE dorsal excitatory motor neuron DI dorsal inhibitory motor neuron VE ventral excitatory motor neuron VI ventral inhibitory motor neuron bending behaviour neural path importance of the interneuron PD Dorsal Pressure sensory neuron PV ventral Pressure sensory neuron INs Interneurons Habituation and sensitization of whole-body shortening, role of S-cell (Modney 1997) • Habituation • Less excitable- loss in presynaptic S • Sensitisation postsynaptic Sensory input is provided by stimulating electrodes Motor output is measured via a tension Posterior electrical stimulation weak→ habituation Strong → sensitization Lesion -S-cell ablation
Maize stem borers in Sub-Saharan Africa - the application of push-pull
Semiochemicals can be effective but may need an integrated approach Chilo partellus and Busseola fusca - moth species whose larvae eat maize stems Crop also infested with Striga- witch-weed costs lots of money trap crop attracts moths (Sudan Grass or Napier grass) intercrops attract natural enemies, push moths away (molasses grass/silver leaf -Desmodium) stem borer larvae survive better in maize than Napier grass Melinis minutiflora molasses grass reduces stem borers in maize more effectively than other intercrops, increases parasitism air entrapment from crops coupled gas chromatography-electrophysiology (GC-EAG) Electrophysiologically active compounds identified in host plant volatiles dissemination of info Striga removal by hand Striga hermonthica damage to maize before emergence Desmodium intercrop also controls Striga (seen by leaching experiment) structure elucidation by various NMR techniques mass spectrometry techniques microreaction UV spectroscopy economic payoffs of push-pull tech livestock/dairy production household food security and income soil fertility improvement commercial seed (Desmodium)
pheromones in insects
Sexual attraction, trail-following, territorial boundaries, alarm, aggregation... Sub nanogram to a few micrograms emitted 1000 molecules/ml of air to elicit a behaviour 7000 species and 3500 semiochemicals Different functions : hydrocarbon, alcohol, aldehyde, ketone, acetal, epoxide, ester, lactone, terpene, peptide, steroid... Chirality is important for bioactivity plants use chems for protection against herbivores e.g. glucosinolates in cruciferous crops have been reduced by plant breeding as humans also find them distasteful (cabbages) e.g. nicotine in tobacco Pyrrolizidine alkaloids such as senecionine in ragwort Isoprenoids or terpenoids aromatic compounds found in many plants including eucalyptus, ginger as well as cannabinoids from cannabis and many others. Cyanogenic glycosides stored in a vacuole and release HCN when attacked e.g sorghum, barley, flax, cherry kernels Lachrymatory factors in onions and other allium species Vanilloids in Chili peppers Essential oils such as citrus oils
exercise: calc profitability
Should a lion hunt Thompson's gazelle, buffalo or both? Decision - when a lion encounters a prey item, should it attack or keep searching? Currency - max profitability = (Energy/Time) Constraints - prey are encountered sequentially - time spent searching and handling are independent - lions have perfect knowledge (i.e. profitabilities and densities of prey are known) Define variables Ei = energy provided by prey i hi = time required to catch and consume (handle) prey i Si = search time required to find prey i (depends on relative abundance) Profitability = Pi = Ei/hi Assume Eb = 40 kcal, hb = 2h Eg = 10 kcal, hg = 1h Profitability of buffalo = 40/2 = 20 kcal/h = most profitable Profitability of gazelle = 10/1 = 10 kcal/h Catch and eat current prey only if the energy gained exceeds that expected if lion searches for alternative prey. Ecurrent / hcurrent > Eother / (Sother + hother) If buffalo is encountered: Eb / hb > Eg / (Sg + hg) = 40/2 > 10/ (Sg + 1) This is always true, even when Sg = 0 So lions should always eat buffalo... why don't they? If lion finds a gazelle: Eg / hg > Eb / (Sb + hb) Rearranging gives: Sb > (Eb / Eg)(hg) - hb So chase gazelle whenever: Sb > (40 kcal / 10 kcal)(1h) - 2h Sb > 2 h Therefore: if finding a buffalo only takes 1h, lions should look for buffalo, but if it takes 3h to find buffalo, lions should chase gazelle. 40 divided by 10 is 4, times by 1 is 4, minus 2 equals 2 Always eat the most profitable prey type. Only include less profitable prey type when the most profitable becomes rare. It is the abundance of the most profitable prey item that dictates when to switch preference.
chem ecology- the future?
Smart sensing to optimise farm inputs: sensitive sentinel plants detect problem, not just pests, diseases and weed competition but also depleted or excess nutrients and water, and signal to main crop of smart plants, with natural response to signal SLMs linked to gene expression (by GM) to deal with problem (or opportunity)
annelids
So the more complex annelids have a simple brain - large cerebral ganglia and a nerve ring encircling the oesophagus DIAGRAMS
celestial cues at night
Star compass in Indigo buntings used a planetarium Indigo buntings have a critical period when they imprint on the night sky, just before their first migration. put in Emlen funnel Emlen funnel has a dark surface covered in thin white paint, and when the birds try to fly in a certain direction, their feet scratch off the paint and show the direction they were trying to go.
steps in acquisition of food
Step 1 - the location or detection of food: Could leave to chance, i.e. hope it passes by (e.g. sponges filter feed; cnidarians snare food OR can be mobile but don't want to waste energy- ambush; spiders build snare) Can actively seek food - use senses, sometimes special ones! (Sight, e.g. birds of prey. Olfaction, e.g. some vultures can smell carrion over 1 mile away; insects have excellent olfactory systems. Hearing, e.g. owls. Touch, e.g. star nosed mole. Special senses: Echolocation, e.g. bats. Electro-sensing, e.g. sharks. Thermo-sensing (IR), e.g. snakes.) Step 2 - securing your meal: Food may be immobile - no problem. Food may be mobile but small - can easily overpower without threat. Food may be mobile but large and could inflict injury - need some extra help to immobilise it.
venom delivery systems
Stingers - wasps and scorpions (wasps/bees have fixed stylet, oscillating lancets, venom flows between them). cnidarians Cell that contains a nematocyst, a capsule containing an ejectable harpoon and thread. Cnidocil is a trigger mechanism sensing touch by prey. Lid opens and tube becomes everted. Loaded with venom. Sea anemone venom contains a peptide toxin (ATX-II) that prolongs action potentials in prey and thus paralyses. cone snail Venom may contain up to 200 different toxins targeting voltage-gated sodium, potassium and calcium channels, nicotinic acetylcholine receptors and ionotropic glutamate receptors. Produced in venom duct. Primed in radula sac. Loaded into proboscis. Two stages to immobilisation. Lightning strike (fast) - toxins with gain of function at voltage-gated sodium channels (δ-conotoxins) and loss of function at voltage-gated potassium channels (κ-conotoxins) cause rigid paralysis. Followed up by toxins that inhibit voltage-gated sodium channels (μ-conotoxins), voltage-gated calcium channels (ω-conotoxins), and nicotinic acetylcholine receptors (α-conotoxins) that cause flaccid paralysis. Sometimes snails release chemicals that sedate fish before engulfing and then harpooning....
smell
Survival: Find food, avoid predators Communication: define home range, attracting mates, recognising individuals, Dogs Can identify an individual odour in mixtures of odours (< 11 odours in a mixture with 100% success). Detection of illegal substances, food, explosives, disease pheromones danger of sending signals- eavesdroppers
Initiation of swimming behaviour
Swimming is episodic not continuous Stimulated by tactile/water wave/current Swim towards source Process of mechanotransduction Under control of command-like neurons Swimming vs crawling vs shortening Transduced by sensillar movement receptors (SMRs) sensory hairs clustered at sensilla located on each midbody segment Cascade of events: sensory trigger gating Flattener muscle act to pull dorsal to ventral and flatten leech Dorsal and ventral longitudinal muscles contract antiphasically • Command neuron on all the time • Trigger neuron only sometimes • Sensory > trigger/control > gating/control > oscillator interneurons > motor > muscles PHASE DELAY BETWEEN EACH GANGLIA LEADS TO SWIMMING WAVE
parental care - distribution across taxa
Teleost fishes: 21% of families show care - 61% have male parental care Amphibians: 71% show care - 50:50 maternal:paternal Birds: 99% show care - Usually biparental Mammals: 100% show care - Usually maternal always exceptions Randall's jawfish- male uniparental care black tamarin- biparental care cassowary- male uniparental care parental care in insects? epilamprine cockroaches (carry under wings) burying beetle (finds dead mouse/bird, buries it, lays eggs nearby, something to feed them when they hatch, adults also regurgitate food for them, feed older grubs preferentially, increased growth in young) earwig burying beetle Parental care (feeding) for the senior offspring, leading to faster growth (and greater survival?) Faster growth rates are important for young animals, they spend fewer days as vulnerable grubs, and a bigger overall size can lead to greater egg laying capacity for females, and better overall survival for both sexes.
why communicate
Territory defence and conflict resolution Sexual advertisement Social integration Parental care Transfer environmental information -predator alarm calls -food location
Basic assumptions of evolution and behaviour
The principal evolutionary force shaping behaviour is natural selection Differences in behaviour between individuals have (or had) a heritable (genetic) basis Selection is between alternative alleles or other replicators [gene (replicator) selection] rather than individuals or other higher order entities.
habituation
The ragworm example shows that animals will eventually get used to (or habituated) a stimulus that poses no real threat to them. So a moving shadow causes these worms to retreat into their holes but they eventually respond less and less, and when tested again some time later, they will perform the same reaction. But, with the mechanical shock stimulus, which involves dropping a weight onto the bench next to the tank, they have to go through the same process over again and eventually learn with enough repetition it is no threat and reduce their reaction to the stimulus. The training for the shadow stimulus is not the same as the shock stimulus, one does not prepare the animal for the other, they only respond to single stimuli at a time and become habituated to each independently. stickleback animals will reduce complex behavioural responses as they become habituated, in this case to the neighbours of territorial males. You will wear out if you act with full aggression every time you meet your neighbour, so male sticklebacks become habituated to their presence. In this experiment, the fish were presented to the males in their territory by placing them in the tank in a glass tube, it could be the same fish in the same spot or different fish in different spots, simulating a foreign intruder. They put the intruders in for 30 mins, then had a 15 minute break, then put in the fish, either the same in same spot or different in different spots. Males got used to the 'neighbour' fish very quickly, but were aggressive at a higher level to intruder fish.
Optimality/game theory and the 'phenotypic gambit'
To examine the evolution of a character as if the simplest genetic system controlled it. i.e. as if: each strategy was encoded as a separate allele at a haploid locus the cost/benefit payoff rule gave the number of offspring for each allele (strategy) enough mutation had occurred to allow each strategy in the set the chance to invade (the population is at evolutionary equilibrium) mostly ignores all of the mechanisms and details of the underlying genetic architecture. This is called the phenotypic gambit... Behaviourists are assuming that these things probably won't matter and that evidence of fit between a behaviour and its current function is enough to explain its adaptiveness and evolution. All strategies in a population are equally successful, and are at least as successful as any feasible non-occurring strategy that might arise in small numbers.
producing/storing venom
Venom glands have secretory cells. Storage can be awkward because of self-toxicity. Toxins often stored as pro-toxins. Compressor muscle contracts to eject venom.
why study inverts? experimental models for understanding neurobiology of behaviour
Vertebrate brains - complex - human brain ~10(12) neurones / 10(16) synapses One approach is to study simpler parts of complex vertebrate nervous system but this has problems! Alternative, study simpler nervous systems, i.e. invertebrates can relate molecular/cellular events to behaviour Simple nervous systems, large cells, topologically typical , stereotypical behaviour, defined genomes. Ecological role of invertebrates Pollination Disease Soil fertility Food chain Others? effect of man Adverse effects of man on these? Plastic pollution Ecopharmotoxicology herbicides, pesticides Global warming Air pollution
Touch e.g. star nosed mole
Virtually blind. Nose is highly modified with 22 appendages. These have excellent touch sensitivity. Used to find worms etc. in soil. Sensory papillae on their nose parts called Eimer's organs. Each appendage (ray) is covered in Eimer's organs. Estimated 25,000 in total. Each Eimer's organ is innervated by 4 or more (rays 10 and 11) myelinated nerve fibres. Merkel cells are mechanosensory cells that synapse with sensory neuron. Lamellated (pacinian) corpuscles are special nerve endings that sense pressure. DIAGRAM?
CPG locust flight
Wings in crickets depressors/elevators 180 degrees out of sync site of inhibition goes round elevator goes up, depressors inhibited and vice versa CPG drives flight rhythm driven by command neuron and oscillations occur due to interactions of inhibition, disinhibition and delay DIAGRAM
insight
Wolfgang Kohler Not trial and error Chimps looking at bananas hanging high, one chimp worked it out quick w/o going through steps in solution physically perceived new associations between stimuli (poles) and outcomes (bananas)- could they be learned associations? Is it mental 'trial and error' rather than 'aha!' insight? Could it be a concatenation of previously learned but separate associations? e.g.: previously learned that can climb on boxes to get higher, and that remote objects can be manipulated with a stick; combine these notions... Did not perceive a novel solution in one conceptual leap? How does intelligence evolve? DIAGRAM
food preferences
Wrenn et al. (2003) mice ate cinnamon/cocoa flavoured food placed in cage w other mouse 24hrs later given choice observer ate more of cued food then novel food amount consumed correlated w no. of sniffs
Leks
aggregations of males at traditional display sites that females visit in order to choose a mate but which contain no resources of value to either sex 'Hotspots' - males aggregate at sites used regularly by females for other reasons (e.g. to access food or water) (e.g. some birds of paradise) e.g. Sage grouse 'Hotshots' - males aggregate around particularly attractive individuals (e.g. some territorial frogs and toads) e.g. black grouse Yearly shift of lekking site suggests male attractiveness, not position, is important. e.g. wild turkey Turkey brothers cooperate on leks. The subordinate chases off other males, and eventually inherits the top spot Reduced risk of predation - aggregating in order to indulge in conspicuous display may reduce individual risk of predation to both sexes (e.g. frog choruses) e.g. greater prairie chicken / sharp tailed grouse Mixed-species leks of prairie chickens and sharp-tailed grouse may reduce predation for both. Prairie chickens may get better deal as they display more and are less vigilant than sharp-tails. Signal attractiveness - aggregations may be easier to spot and/or present a stronger, more complex and more attractive signal (e.g. many insect leks) e.g. Synchronous firefly light show great smokey mountains, TN
central place foraging
animal goes and finds food from a fixed point, think of a rich patch of food that an animal can return to again and again e.g. starlings Experiment: starlings must collect larvae from feeder and return to nest to feed chicks Load curve shows diminishing returns as beak fills up Use MVT because parents want to maximise energy gain of chicks Observations fit MVT predictions experimental test of the marginal value theorem using starlings. If the distance is long, the starlings spend longer filling their beak to capacity, if the distance is quite short, then they fill their beaks quickly and lightly and make more trips
George Romanes
animal intelligence 1882 collection of anecdotes now animals differ in their intelligence, one is not more intelligent than another
how does sexual selection arise?
anisogamous sex > parental investment > sex ratios > mating systems > competition for access to/to attract mates
Electrolocation in weakly electric fish
knifefish occurs when animals that can generate their own electric charge e.g. a carapo freshwater fish, bounce the electricity off non-conducting objects in their river, like wooden logs and stones, to produce a map of open water and objects that they can navigate in the dark or when the water is clouded with rotting plant matter and silt.
bilateral and segmental neuronal networks
annelida ganglia organisation paired (often fused) and extend length of animal ventrally Segmented, 21 each ~400 neurons, map and link to function Individual ganglia, autonomous, control complex behaviours feeding, swimming, escape, etc Nerve roots extend from ganglion roots to periphery muscles, skin - motor & sensory Fusion of ganglia in head region form a rudimentary brain Ganglia interact, head-tail ganglia coordinate overall head ganglia, connectives, roots (off to side) Bilateral ganglion pairs mirror, act as autonomous units Remove first ventral ganglion earthworm stops eating & does not burrow Ganglia interact, head-tail ganglia coordinate overall Cephalic ganglion important for movement control remove → earthworm moves continuously Connectives link individual ganglia longitudinally Commissures link ganglia laterally Can map & identify function of individual neurones trace neural connections Cell bodies arranged around ganglion periphery centre processes & synaptic contact region Cell bodies not identical - different size & pigmentation located in same position in different individuals - useful experimentally DIAGRAM commissures connect middle inside paired ganglia connectives join diff segments roots off side of pairs ganglia
acorn barnacle
balanus balanus Complex behaviours Feed, motility, escape predation and reproduce Neuronal electrical activity explains behaviour Shadow reflex DIAGRAM Shadow hyperpolarizes Vm of photoreceptor Electronic spread to synapse DOWN-Ca2+-dependent histamine release I cell depolarizes UP-output to motor neurons Adductor muscle contracts photoreceptor: dimming hyperpolarises (more neg) the receptor decreases HA release postsynaptic cell: disinhibiting the postsynaptic cell, eliciting signal transmission along the visual pathway photoreceptor: light, inhibitory HAergic synapse postsynaptic cell: excitatory response barnacle photoreceptors 1. connective 2. supraesphageal ganglion 3. nerve stalk 4. ocellar nerve 5. photoreceptor DIAGRAM Receptor potential response of photoreceptor to illumination Response of photoreceptor and I-cell to illumination or electrical depolarization DIAGRAM I-cell (postsynaptic): sharp increase photoreceptor (pre) UNCONVENTIONAL INHIBITORY SYNAPSE Histamine normally constantly released during illumination Depolarized photoreceptor Act to inhibit post-synaptic cell Light Reflex results from interruption of this Photoreceptor hyperpolarizes Interrupts histamine release Disinhibition of I-cell Response due to inhibition not stimulation of release Dependent on dissociation from post-synaptic receptors, clearance from cleft and closure of channel Not release kinetics and channel opening like for excitation
hearing
barn owls (Konishi see Takahashi, 2010)- sound localisation to catch prey echolocation bats- produce sound and listen to echoes flying in the dark, tracking and catching prey
bilaterians
bilateral symmetry, i.e. a head, a tail, a back and a belly. Nervous system also has bilateral symmetry. A head with specialised functions perhaps resulted in clustering of neurons at this end. Known as cephalisation. Resulting in a brain. Simplest (most primitive) bilaterians include flatworms and roundworms.
medicinal leech: Hirudo medicinalis
body plan DIAGRAM
Cues used in longer distance orientation and navigation
celestial cues Earth's magnetic field gravitational field barometric pressure polarised light landmarks odour infrasound...
radial neuronal network
cnidaria- hydromedusae radial symmetry nerve-ring network, no brain/ganglia coordinated swimming behaviour that reflects pacemaker activity, neuronal network and body plan
first NS
cnidarians hydra, sea anemones, corals and jellyfish. Simple nerve nets in hydra (and sea anemones). DIAGRAM? some organisation in jellyfish DIAGRAM jellyfish have photoreceptors, can respond to changes in light/shadow
Vision
colour Humans have 3 colour receptors (blue, green, red) Bees: green, blue, ultraviolet (see Birds: e.g., blue tits perceive UV pigeons have >6 colour receptors polarisation orientation of the oscillation of the waves some animals can detect this and use it as a compass- polarisation of light changes w the position of the sun works on cloudy days shown that many inverts are sensitive and some birds/fish
How to study learning?
comparative studies between-species comparison Clark's nutcracker is a food storing specialist, it can hide 9000 items and remember where each one is 9 months later. It has a pouch to carry the items in to the storage sites. When the bird and it's related species were tested in a lab using pecking at a computer screen, we can see the specialisation that the Clarks nutcracker has to remember position over time. Not so good at remembering colour. between-species comparison meadow/prairie voles polygynous/monogamous mating system sex differences in spatial learning females make more errors in polygynous system males need to remember territorial boundaries within-species comparison Zenaida dove Learning to pull a ring to open a drawer for food territorial population pass learning trials less than group-living Group livers do better in the task because social environments allow social learning which might also enhance general learning abilities in the individual
Intrasexual selection
competition for fertilisations within one or other sex (usually males) Leads to the evolution of traits associated with competitive ability e.g. large size, weaponry, traits indicating good physical condition Pre-copulatory selection - contests settled on the basis of asymmetries between contestants Post-copulatory selection - competition between ejaculates - sperm competition
who should provide care?
cooperative breeding Defined as adults that are physiologically capable of breeding independently but instead provide care to other adult's offspring Called 'alloparental care' or 'helpers at the nest' Observed in birds, mammals and fish Helpers: - often reside in the breeding territories - often related to the adults they are helping - sometimes 'sneak' reproductive opportunities 220 species of birds have helpers at the nest 120 species of mammals have some form of alloparental care - e.g.: communal nursing e.g. long tailed tit, meerkats, superb fairy wren phylogenetic pattern in birds more examples from certain groups than expected (e.g. new world wren, bee eaters, jays) do helpers help? They might not help, just eat all the extra food and be really bad at raising your offspring. The majority of evidence says that helpers especially help inexperienced breeders, and even help when conditions are particularly poor. Is the increase in production just because the territory is very high quality and can support lots of helpers and provide lots of food to the chicks? why not disperse? Ecological constraints: habitat or mate saturation - dispersal is difficult or risky - species defend year-round all purpose territories - residency improves competition for territories and mates Group living is advantageous e.g. Seychelles warbler When birds were introduced to a new island to save them from extinction, they only became cooperative once good territories filled up. mate limitation superb fairy-wren Male helpers are usually sons, so if the male breeder is removed the helper may disperse as the female is his mother. If the male and female breeders are removed, then the male helper stays to see what new female may come along as they will not be related to her and can breed with her why help? Nonadaptive result of parental 'instinct' Increase fecundity (unlikely) - parenting practice - no evidence Increase own survival (perhaps?) improving survival of offspring increases group size Enhance breeding opportunities (sneaky mating) Increase inclusive fitness (WIF) of helper WIF = WH + rBHWB Where: W = fitness, B = breeder, H = helper Enhance breeding opportunities (sneaky mating) -Helpers recruit offspring to join coalitions e.g. Green woodhoopoes -Gain access to mates e.g. Stripe-backed wrens Increase inclusive fitness (WIF) of helper By decreasing parental feeding rate, which enables: enhanced survival (Florida scrub-jays) increased breeding (Grey-crowned babblers) Increase inclusive fitness (WIF) of helper by improving offspring survival: -reproductive success correlates with helper number (independent of territory quality) -must preferentially help close relatives e.g. silver-backed jackal and white-fronted bee eaters (larger group size, more pups surviving) Increase inclusive fitness (WIF) of helper Helpers are usually related e.g. white fronted bee eaters When breeding attempts fail birds help at nests of close relatives
attractiveness of humans to biting flies
cows producing 'repellant' less attractive some humans make compound that repels mosquito (repellant may work by masking 'attractant') Volunteers were tested for attractiveness to mosquitoes using a y maze with a hand held in the stream of air in one arm Entrained air collected from volunteers contained in a space-blanket bag Tested with GC coupled EAG in mosquitoes Aedes egypti Compounds were related to unattractive volunteers as potential antifeedants or "repellants" Latest studies using identical and non-identical twins show trait is heritable.
manipulation
cuckoo Single chick vs. whole brood vs. cuckoo chick. Other species of cuckoos have evolved eye spots inside the gape (mouth) that resemble an entire brood of chicks in a dark nest
Prisoner's dilemma
defined by: T > R >P > S and R > (T + S) / 2 ESS for single round of the game: always defect! T = Temptation (max reward, freedom) R = Reward (mutual cooperation, only 1 yr in prison) P = Punishment (mutual defection, 5 yrs) S = Sucker! (max punishment, 10 yrs) T=5 R=3 P=1 S=0 If the Prisoner's Dilemma game is played repeatedly with the same pair, long-term strategies can develop Iterating this game allows for cheating - the key distinction between mutualism and reciprocity Iteration permits complicated strategies, e.g. one player can perform CDCDCCCD while another might do CCCCCCCC, etc. Tit-for-tat (cooperate on the first move and thereafter mimic your opponent) is the best strategy - an ESS MUTUALISM where same strategy always played bc anything else=death See in nature w vampire bats (Desmodus rotundus) food sharing Bats that share when there is need should live much longer than selfish individuals. Recipients are always frequent roost members and often relatives Grouper + octopus in Planet Earth II (but only single observation)
what is learning
development of perceived relationships between events in the environment (Dickinson 1980) Learning allows adjustment of behaviour to suit the local environment through experience of that environment Some problems: Learning can be difficult to distinguish from other causes of change in behaviour over time Recognising learning depends on seeing a change in behaviour, but learning may occur without any such change or change may occur without learning Problem of identifying relevant events in cause-and-effect relationships What are the conditions that allow learning to occur? What is learned? How does learning affect behaviour? conditions that allow learning should be reliable correlates of the state of the world that the animal needs to adjust to. This means that experience and learning bring about relevant, fitness-enhancing changes in cognitive state and behaviour.
intensity of sexual selection depends on
diff in parental effort between the sexes - where there is biparental care, sexual selection likely to be weak, males have little time to compete for multiple mates operational sex ratio (males:available to females) - if equal numbers of both sexes come into breeding condition synchronously, little opportunity for males to control access to several females
molluscs
diverse in terms of body plan and hence also in terms of nervous system design. Main groups are bivalves, gastropods and cephalopods DIAGRAM cephalopods marked step in organisation and cephalisation. Head ganglia are fused to form a multi lobed brain. Well developed eyes - important for communication DIAGRAM stellate nerves/ganglia in mantle chromatophores contain pigment or have light reflecting properties Each chromataphore is 'driven' by an array of radial muscles under the control of numerous nerves. Requires a lot of computing power. DIAGRAM
switching between mating systems
dunnock (birds) Conflicts of interest between males and females Females do best under polyandry - try to exclude other females Males do best under polygyny - drive off other males, stop females driving females away Females evade mate-guarding males and solicit extra-pair copulations to gain extra paternal care Outcome depends on resource distribution and individual competitive abilities. Polygynandry arises where neither sex wins out. male parental involvement greatly affects chick survival
Substrate texture and klinokinesis in body lice
like to live in clothing, not on bodies not that common in developed countries will find the substrate they prefer to live on different materials were placed in dishes, and the lice moved to the substrate they preferred preferred woolen and cotton stockinet to silk that's why silk clothing became the reserve of the richest class in society klinokinesis is looking for a suitable substrate
alarm calls
e.g. 'hawk' alarm calls, directed at conspecifics (avian alarm calls v similar so other prey spp. can understand) avian calls can be discreet or public A great tit will give the mobbing call to every small bird around it while approaching the hawk when it is perched in a tree, then they can gang up on the hawk and possibly drive it away, but if the great tit spots a hawk flying, and presumably hunting, then it gives a quiet seet call that is intended for it's mates and offspring that may be nearby only (attenuates quickly, short-range, quiet- hawk might not know where it's coming from) e.g. Belding's ground squirrel call most w offspring in home cot, least without close gen. rels. in home
sensory exploitation
e.g. Courting male water mite (Neumania papillator) exploits prey-catching cues of female (water vibrations caused by copepod prey) Female Zebra finches (Taeniopygia guttata) prefer males with red plastic leg rings - perhaps exploiting an existing preference for red (e.g. bill colour)
electricity (shocking)
electric fishes electric eel/torpedo ray electric catfish and stargazer fish Electric organ is modified muscle tissue. Produces electrical pulses at high frequency. Electric organs consist of many specialised cells called electrocytes. Used to momentarily stun prey. Electrocytes have two distinct faces and are all oriented in the same way in stacks. Each electrocyte can generate a potential difference of 150 mV. 5000-6000 lined up in organ. Organ is capable of generating a potential difference of up to 860 V and pass current of about 1 A 860 W of power. Only one face of the electrocyte is innervated and is rich in nicotinic acetylcholine receptors. Acetylcholine release depolarises the membrane on one side of the electrocyte. It becomes polarised.
echolocation and sonar topography in bats
emitting noises that bounce off solid objects and provide a map of the surrounding area even in pitch black. They also use it for hunting, as represented here, and it was first discovered that bats used sonar by a researcher who put the bats in a dark room strung floor-to-ceiling with chains and observed they navigated around them, then he deafened them and found that they crashed into the chains
Stay‐at‐home strategy brings fitness benefits to migrants
european winterers earlier initiation of nests higher breeding success/chick condition trans-saharan migrants later initiation of nests in older chicks lower breeding success/chick condition residents higher nest success earlier initiation of nests resident-resident pairs do best short dist migrants lower nest success later initaion of nests
emulation
exact actions not reproduced by observer
eusociality
extreme cooperation • Overlapping generations • Parental care in a permanent nest • Reproductive division of labour including nonreproductive (or sterile) workers - Caste polymorphism (in some cases) e.g. social spiders (Stegodyphus) Hymenoptera (haplodiploid): ants bees and wasps ants show extreme caste polymorphism Isoptera- all termites (diploid) Naked mole rats (diploid) Tasks that an individual does is dependent upon weight and body size. Job roles = 'castes', includes morphological changes in the queen. Dispersing class - lazy and fat until times get tough, then have the energy reserves to move out and start a new colony.
e.g. sex pheromone in diamond back moth
field use of pheromone traps Sticky traps and water traps baited with pheromone can be used for monitoring or control
partial migration in blackbirds
frequency dependent model (or, conditional strategy) Being a migrant is a less preferred option in terms of fitness and survival and in the case of blackbirds, they can switch between migrating or staying. It appears that as blackbirds age, they become more socially dominant, and it is older males that are more likely to be resident from year to year, and the females and and young males that make the switch between behaviours dependent upon conditions.
Adaption and learning
genes, selection and learning functional (reproductive) significance salience and 'constraints on learning' comparative studies Learning is an adaptation in itself, so it has as much genetic basis as any other trait
genomic imprinting and development
genomic imprinting and growth rate in mice form of gene regulation where some genes are silenced if they are inherited from the father and some genes are silenced if they are inherited from the mother. Here we see a gene Mest affecting growth rate in mice depending on which parent they inherited the inactive copy from. Genomic imprinting can profoundly affect development and phenotype, and is only just beginning to be understood.
IR detection
greater wavelength than visible (to humans) light Wavelength = 700 nm to 1 mm. Most thermal radiation emitted by objects is IR. So warm blooded animals emit IR radiation. Some animals are able to 'see' IR. Snakes -pit vipers, pythons and boas. Vampire bats. Bed bugs. Some beetles. None of these use their eyes to see it pit vipers: Loreal pits contain IR sensory cells. Pits can sense a 0.03 °C temperature difference. effective up to 1 m distance. membrane separates an outer and inner chamber. The membrane is innervated by trigeminal ganglion (TG) neurons that are rich in TRPA1 ion channels. TRPA1 is a temperature sensitive ion channel Rattlesnake TRPA1 is more sensitive to temperature increase compared to non-pit snakes. In mammals TRPA1 senses noxious cold and noxious chemicals including mustard oil (AITC). IR input from trigeminal nerve converges with visual input from optic nerve in the optic tectum of the brain. Visual and IR images may be combined. vamp bats: use IR detection to locate blood vessels in warm blooded vertebrates. Have pit organs like snakes, but three of them surrounding the nose. The nasal structure maintains a temperature 9 °C lower than the rest of the face. Pit organ membrane has TG neurons rich in a TRPV1 ion channel isoform known as TRPV1-S (short form = splice variant). 35-46% of TRPV1 transcripts in TG neurons are TRPV1-S compared to <6% in related insect/fruit eating bats. TRPV1 is heat sensing ion channel in mammals with threshold of 43 °C. TRPV1-S has a threshold of 30 °C. Vampire bat IR receptors shown to have sensitivity of >28 °C.
Control of ingestive behaviour
hedonic: taste, smell, visual appearance, social environment homeostatic liver > FGF21 pancreas > insulin glucagon GI tract > PYY/CCK GI tract/stomach > ghrelin fat > leptin PYY = peptide tyrosine tyrosine (PYY) GLP1 =glucagon-like peptide 1 (GLP1) CCK = cholecystokinin control of ingestive behaviour DIAGRAMS (other way round) Satiety stomach full > ghrelin to brain stretch receptors L cells duodenum > GLP-1/PYY > CCK > brain • Ghrelin promotes feeling of hunger when stomach empty • Leptin receptors in diff regions of hypothalamus MCH orexigenic pathways NPY orexigenic POMC anorectic (hunger?) Effects of ghrelin on BOLD response in fasted subject discovery of leptin 1940s ob/ob mouse: massively obese phenotype 1970s ob/ob mouse lacking a circulating factor that suppresses appetite (parabiosis experiments) 1994 ob/ob gene cloned: encodes 'leptin' leptin treatment reduces body weight in ob/ob mice Fat-brain signalling: compensatory responses protect against starvation increase appetite metabolic rate decreases reproduction decreases leptin decreases lipolysis decreases many systematic metabolic hormones influence ingestive behaviour
arthropods
huge group of animals so very diverse body plans and therefore nervous system. Insects, crustaceans, arachnids, myriapods. Tend to have a well defined head with eyes and thus cephalisation, i.e. they have a basic brain. Also have thorax and abdomen. More complex behaviours including social interaction in some cases. have ventral nerve cord w pairs ganglia supporting each body segment, though pairing isn't always obvious due to lateral fusion in some cases segmental arrangement also lost due to anterio-posteria fusion of ganglia, e.g. fly, spider
'Bourgeois' strategy
if player already owns resources Speckled wood butterflies Sunspot territory Warms flight muscles, ectotherms DIAGRAMS Golden digger wasp
Inter/intra ganglion connectivity is complicated
inhibitory/excitatory synapses rectifying (unidirectional) gap junctions
many factors influence insects finding crops
innate oviposition preference (host/non host) hierarchy current environmental conditions (predators/parasitoids/defence/nutritional quality/pathogens/availability/intra- and interspecific) phenotypic plasticity (larvel/adult experience) larval preference (larval mobility) actual oviposition choice how do we find what factors are involved/use that knowledge? Identify a behaviour which may involve semiochemical signalling and design a hypothesis Try to identify the precise chemical or chemicals to which the insect responds Identify the concentration range which produces the response Test the effects of the suspected compound in lab and field conditions Characterise the chemical ecology - does the compound interact with other species Design ways to apply the knowledge. identifying active compounds: air entrapment/coupled GC-electrophysiology, antennal detector (electroantennography) reference/recording electrodes • Identifying active compounds- separate chemicals that you've collected from columns and blow at insect • Which does it respond to • Measure electrical signals in antennae
Reasoning
insight as a form of reasoning forming conclusions that go beyond what is immediately available Piecing experience together in novel ways Possible explanation for Kohler's findings Epstein, Kirshnit, Lanza, and Rubin (1984) Pigeon trained to climb on box and peck banana Pigeon trained to push box towards spot Test - banana + box (no spot)
e.g. calculated migration over short distances
inter-group transfer in gorillas determine whether to move groups based on the ratio of silverbacks to females and young. For breeding females the most attractive groups had a higher ratio of available silverback male to females and young for protection against predators. When neighbouring groups encounter each other, sometimes females will transfer to the other group if there are fewer females and young, and it is more likely that there will be better protection
Landmarks and local orientation in coral reef fish
lionfish and clown anemone fish reef is often not continuous, but is made up of little underwater islands called bommies. The fish move between these, and need to find their way back to their home bommie, so it is theorised that they have a navigational map of landmarks in their heads, as each bommie is unique.
locomotor behaviours of the leech
local bending (dorsal, ventral, lateral) swimming shortening feeding crawling
electro-location e.g. sharks n rays
locate prey by detecting the electrical fields produced by muscle activity electro-sensory organs called Ampullae of Lorenzini Distributed around the head esp. dense on the snout. canal of Lorenzi (jelly-filled tubule) gel is a glycoprotein based substance w semiconductor properties nerve fibres surface pore denticle electrical impulses travel thru canal to stimulate ampulla nerve impulses then send info directly to brain Sensory cells have many voltage-gated calcium channels (VGCCs). Negative V depolarise the sensory cells and activate VGCCs. Ca2+ enters the cell and causes release of neurotransmitters at synapses. Nerve is stimulated. Ca2+ also activates potassium channels in sensory cells and these repolarise the cell. • High density of VGCCs • If surrounding neg electric field, depolarise membrane • Ca flow into cells, release of nts, stimulate nerves, electric field detected
magnetic sensitivity
many animals shown to be sensitive to magnetic fields: pigeons, bats, migrating fish, bees, ants, cattle, sea turtles (Lohmann et al., 2004) Sea turtles can distinguish different locations by the magnetic field
Biological clocks
many timescales circatidal (~12.4 hr) e.g. crab circadian (~24) circalunar (~29.5 d) e.g. bristle worm circannual (~1 yr) e.g. starling longer, e.g. cicada (~17 yrs) most organisms have circadian clocks (verts, inverts, higher plants, single cell orgs)
social aggregation
mating advantages Ruff bird 4 male morphs (1 is female mimic) Lek-based mating system The bigger the lek, the more mating for subordinates social behaviour and mating success nurturing offspring: parental care, family groups, creching - parental quality, competition to attract mates resource defence - competition for access to mates
Theory approach to mechanism
mating of the smooth newt. male has to encourage female to follow him before he can be confident that she will accept his spermatophore. series of movements awaits the appropriate response important that the female, for example, touches his tail before spermatophore deposition or he might waste his gametes. treat the 'interest' of the female like current in a circuit in order to model what will happen next and when. oxygen debt predict when a male will give up on any of these activities before he runs out of oxygen? circuit board modelling how the male newt should perform his sequence of behaviours. There are gateways leading to the ultimate final act, spermatophore transfer, but he can be 'reset' any time the female fails to respond. If he drowns, then he cannot mate with any other females. F is the readiness of the female to mate, or her interest S is the sperm supply Hope (of the male for a successful mating) depends on those two things. During 'retreat display', Hope increases. (boxes k1 and k4) Until it reaches threshhold value T2, upon which he switches to 'Creep'. During creep the male's Hope goes down as he cannot see the female anymore. This means there is negative feedback via k2 In the MODEL the spermatophore transfer occurs when a certain amount of 'Creep' is performed (T3) but in REALITY the male needs the tail-touch from the female to know she is still there. If Hope decreases to below the level of T1, the male goes back to 'Retreat display' G = the oxygen debt will affect the rate of decay of 'Hope' and the rate increases throughout the sequence as the males run out of air.
Intraspecific variation and game theory models
model for migratory behaviour, to predict when it will be beneficial, or fitness enhancing for an individual of a population to undertake migration Many populations show partial migration, as a mixed ESS, this behaviour can be frequency dependent - it depends on what other members of the population are doing So the performance of the behaviour - go and migrate, depends on environmental conditions like the harshness of the winter, and the individual's competitive ability. e.g. Mild winter - everyone does best by staying Harsh winter - only a small number do best by staying doms can defend resources so always do best by staying subs cannot- always do best by leaving
starfish
more organisation in the nervous system. Nerve ring (surrounding oesophagus) with a radial nerve in each arm. Evidence for sensory and motor neurons. Can detect food and move towards it. Still no clustering of neurons.
spite
more theoretical costs receiver, short term cost to sender humans playing economic games
migration
movement between distinct habitats non-accidental and increases fitness temporally predictable involves return journey on av. would expect movement to be non-accidental/based on info otherwise risk too great to be selected for Migration is an advantage when the potential reproductive success achieved (M) on the way to and in the spatial unit to which the animal migrates (H2) exceeds that which would be achieved during the same period by remaining in the current spatial unit (H1). i.e.: when H1 < H2M
Fitness benefit of a behaviour/optimality theory
net benefit = chances of reproducing per unit time minus chances of dying per unit time Optimality theory assumes individuals want to maximise reproductive output and minimise chances of death. Analyses behavioural strategies without frequency dependence. This is another way of modelling the evolution of behaviour, again using a costs and benefits model. If we wish to model the fitness benefit of a particular behaviour, we need to consider it's chances of allowing the animal a reproductive opportunity.
echolocation e.g. microbats
nocturnal hunters reasonable vision but not as good as other night hunters alt way of locating food echolocation (sonar)- emit call, listen for echo use to detect insects as well as navigating round objects Call is very loud, 60 to 140 dB. But high frequency (14,000 to 200,000 Hz) so often out of human hearing range (20 to 20,000 Hz) Difference in timing and amplitude of echo in each ear gives positional information. Can detect minute changes in frequency to determine whether target is moving closer or away (or is stationary) - Doppler shift call rate increased as bat approaches target amp and sound freq may change too Calls are mostly generated by larynx and can be emitted via the mouth or nostrils. Laryngeal muscles are super-fast! Bats auricles are adapted to collect and funnel echoes. They have numerous amino acid substitutions in prestin, a protein found in the outer hair cells of the basilar membrane in the cochlea, that allows detection of very high frequency sound waves.
bigger brain more intelligent?
not exactly A lot of brain power is spent on control of body systems. So have to take body size into account too. Depends roughly on brain:body weight ratio. But not perfect, e.g. human ratio is about 1:50 compared to ant at 1:7, and small birds around 1:14. Also, consider that in human babies the ration is larger!
flatworms
ns has bilateral symmetry Has a pair of lateral nerve cords (one running down each side) with numerous ganglia connected by transverse nerves. Large cerebral ganglia = primitive brain. Coincide with eyespots. Sensory projections at front...... photoreceptors mechanosensory > chemo > light > interneuron (inwards)
whales that migrate from arctic/antarctic oceans to give birth in warmer water nearer the equator, food cannot provide an ultimate benefit, since the adults do not feed on the calving grounds
other hypotheses calves gain weight more quickly in subtropical waters- invest less energy in keeping warm or less likely to be attacked by predators (esp. killer whales) how to test this? thermoregulation hypothesis generates the prediction that whales born in tropical waters will be born at a relatively low weight or with a relatively thin layer of blubber compared to their adult weight or adult blubber thickness whereas those that are born in cooler or cold waters will be relatively large and blubber rich compared to their eventual adult size. comparative analysis w scientific whaling data? anti-killer whale hypothesis predicts that killer whales will be relatively scarce in waters closer to the equator and that relatively defenseless small or slow-moving whales will be the ones that tend to give birth nearer the equator observational study
spectrum of electromagnetic radiation
photoreceptor units - ommatidia
flying at dusk
photoreceptor/behavioural changes to accommodate shortfalls in sensory transduction In insects Photoreception relay visual motion Tipula slow flying nocturnal cranefly Photoreceptors Slow but more sensitive to light Sarcophaga fast flying diurnal flesh fly Photoreceptors fast but less sensitive to light Low light levels vision for diurnal species less reliable, why? Decreased signal to noise Bumble bees (Bombus terrestris) react accordingly by slowing down but still maintain robust flight patterns In part due to dark adaptions in the photoreceptors Does not have two types of photoreceptors (night/day) Instead Transduction speed of green-blue photoreceptors fall Slower flying gathers more visual information per unit distance Slower photoreceptor response, permits longer post-synaptic event and greater integration times So slower less frequent post-synaptic potentials in low light compensate for faster more frequent singles at high light Also fly slower to aquire more visual information Similar for Hornet workers Nocturnal foraging ants • Background noise in dark • Need to reduce it - slow photoreceptors • Right shifted - Sarcophaga flesh fly (diurnal), higher light intensity, higher % for minimum response • Bumblebees - slower in dark
securing a large meal
physical, electrical and chemical weapons spider silk for tethering components produced by various glands reduction of pH along spinning duct unfolds long proteins DIAGRAM type of silk depends on protein secondary structure About 300 aciniform glands. Produce swathing silk. Wrap prey.
e.g. increased reproductive success choice
poplar aphids leaf selection Females lay eggs in cottonwood poplar bark in Autumn. In Spring they hatch and the females move up the trunk of the tree towards the newly forming leaves can be 10,000s per tree females select leaf and induce gall formation to protect them/their offspring females reproduce daughters asexually within the gall and they're released when mature to disperse and start cycle again select large leaves- aphid mothers produce twice daughters they would have produced if they settled at random competition for large leaves large- more/heavier daughters galls less likely to be aborted by tree fight for biggest leaves, can take hours/might die game theory- payoff is high don't want to share big leaves more females on a leaf- fewer young are produced per gall (per female) additionally want to be closest to the base of the leaf where the nutrient flow is highest. Here are the payoffs in terms of how many offspring are raised for different habitat selections. For a poplar aphid, the right location is vital. And they choose leaf sizes to maximise reproductive potential. This is in keeping with the ideal free distribution
social or independent learning?
potato washing by macaques 1953 - Imo (female) was seen to wash potatoes before eating them By 1958 14/15 juveniles, 2/11 adults were washing potatoes Probably not true imitation: Human intervention? Potatoes given to monkeys that washed them Acquisition of behaviour very slow (mean & median = 2 years) Rate of recruitment did not increase
e.g. heritable preference
prairie deermouse mixed grassland/sparse woodland mainly grassland active choice? Wecker wild mice placed in pens w choice of grassland or woodland (always preferred grass) preferred bc it was familiar? bred some in captivity/reared on all grassland/all woodland all preferred grassland- independent of experience while young heritable choice 2 subspecies P. m. gracilis (Woodland) P. m. bairdii (grassland) preferred ancestral habitats regardless of rearing also temp preference bairdii preferred lower temps (open grasslands, don't retain heat) also earlier locomotory development/greater tendency to burrow- helps in grassland ADAPTIVE 'SKILLS'
development of behaviour
prenatal development of sensory systems visual auditory chemical somesthetic/vestibular > birth superaltricial altricial precocial superprecocial >>>less parental care needed further down nature vs. nurture Behaviours that were vital to the juvenile form of an animal may be completely useless in the adult, some may be retained, but some that are retained may be used in a modified way, think of subordinate animals using the begging postures of young animals to indicate their submission to dominant animals. Then there are many behaviours that are only appropriate to adult animals, such as courtship behaviours. How are these developed? The somesthetic senses convey information about touch, pressure, pain, and out- side temperature. The vestibular receptors in the inner ear are capable of detecting linear and rotational movement of the body. Genes versus environment Maturation and behavioural development Experience and learning Inter-individual differences in behaviour - personality
selection, adaption and personality - sexual selection
rainbow krib fish monogamous, biparental freshwater cichlid did not detect an overall agreement in female mating preference for either male level or consistency of boldness. However, we found disassortative female choice for the level of boldness. Also, female preference increased with similarity in behavioural consistency, suggesting assortative choice for consistency in boldness. divide the labour of reproduction, with one parent tending the offspring and the other defending the territory, so a dissimilar mating choice should allow both jobs to be filled. These roles are not sex-determined, either sex can do them, this leads to disassortative pairing by boldness. SHY FEMALES PREFER BOLD MALES FEMALES PREFER CONSISTENT MALES
dominance relationships
relationships occur wherever associating individuals differ in competitive ability - do they have any functional significance? Regulates access to resources without continual fighting Should occur when the risk of injury from fighting exceeds the gain from resource and individuals interact repeatedly dominance and age male olive baboons young/old- lower rank Dominance and residence age not a factor but longer duration of residence = higher rank Matrilineal dominance Daughters outrank older sisters in female Rhesus macaques can arise several ways e.g. as statistical outcomes of chance encounters, through confidence effects, strategic assessment Animals recognise each other using signals that correlate with Resource Holding Potential (RHP) - status badges - Harris sparrows and House sparrows (black patch- honest signal, can't be faked, darker birds attacked more often) Animals adjust their perceived status on the basis of the outcome of recent contests (winner-loser effects) - fishes Animals adjust their perceived status on after observing contests involving others (bystander effects) - chickens dom relationships can lead to reproductive skew within groups how much reproductive disadvantage will a subordinate tolerate? e.g. elephant seals, beach master e.g. groove-billed ani - in female anis the dominant females lay later and chuck out eggs laid earlier by subordinates - Subordinates may put up with making the 'best of a bad job' or they may reflect an equally viable alternative life history strategy
How do we define behaviour
repeatedly recognisable and measurable units that can reliably be distinguished from each other appear to serve a recognisable function the internally coordinated responses (actions or inactions) of whole living organisms (individuals or groups) to internal and/or external stimuli, excluding responses more easily understood as developmental changes.
Oxytocin
reproduction maternal physiology- partition and milk let down maternal behaviours- nest building, licking/grooming pups, retrieval of pups Ferguson's reflex: OT +ve feedback DIAGRAM • Childbirth, changes in hormones starts process of parturition • Can induce labour w estrogen vasopressin and OT: gene duplication v similar AVP - Phe Arg OT - Ile Leu DIAGRAM Oxytocin and social behaviour DIAGRAM
Estrogen
reproductive physiology: final maturation of ovum, LH surge ovulation, oviduct - cilia/secretion, uterus/cervix/vagina sexual behaviours: proceptive/receptive Proceptive- before reproduction/ovulation, signalling readiness, cued by rises in estrogen e.g. tongue flicking Marmoset Vulval oedema in baboons Vaginal scent marking Syrian hamster appearance: pheromonal/visual Receptive- lordosis Lordosis - female posture that promotes copulation Take away proestrus, not v much lordosis, can be partially restored by adding EB Oestrous cycle- cycle spontaneously or induced ovulation
Functional significance of conditioning
reproductive success in Blue gouramis Reducing the cost of aggression: Territorial males conditioned to expect a fertile female were able to reduce aggression and respond appropriately to defend a territory, males must be aggressive, but if they are too aggressive they will injure or scare females away when males were conditioned to expect a fertile female, they showed less aggression towards her, started building her a nest right away, and when they mated the males that were prepared for mating by the conditioned stimulus fathered over a 1000 young, compared with males that were conditioned to a stimulus but the conditioning had not been paired with a female who just happened across a female. THE MATCHING LAW AND FORAGING Foraging behaviour can be conditioned by the reward schedule. Animals form a stronger association when the reward quality is high, so that they learn to forage optimally. The ideal free distribution predicts that animals will spatially arrange themselves according to resource availability so that each individual gets the same amount of resources
Selection, adaption and personality - predation risk
roach fish/cormorant PIT tagged fish were caught, tested for boldness, released roosts of cormorants were scanned for the tags to check for regurgitated tags from predated fish. more bold- more likely to be predated
calculated migration over long distance
savannah ungulates tough grasses > herb and grass > dicot layer In the Serengeti, herds migrate following the rainfronts. They are opportunistic, following rains that can be seen or heard up to 100 km away. There is a sequence of species, first go the zebras that eat away the tough grasses, then the wildebeest who clear away the herb layer and finally Thompson's gazelle and other smaller species who eat the tiny broad leaved dicot layer. medium-distance calculated removal migration that all adds up to a long distance migration.
communication
sender intentionally produces a signal to convey information to receiver Signal must be perceived by receiver despite attenuation (gradual loss in intensity) caused by transmission through the environment Signal transmission depends on sensory modality used Receiver must discriminate among signal variants and infer meaning as appropriate receiver- decision and response info doesn't always have to be correct, but must be correct often enough for receiver to be selected to respond
information cascade - initiating swimming
sensory neurons > trigger/control neurons > gating/control neurons > oscillator interneurons > motor neurons > muscles DIAGRAM
wider consequences of sexual selection
sexual dimorphism/dichromatism physiological regulation (endocrinology, immunology) social organisation signalling intelligence and culture
Gill withdrawal reflex sensitisation
shock tail and touch siphon after habituation paired pathway - paired stimulation of siphon and tail 5-HT sensitization pathway via tail shock Single electrical stimuli to motor Single electrical stimuli to sensory (no gill response) Repetitive sensory stimuli-gill withdrawal DIAGRAMS Apply excessive stimulation increased response Increase in glutamate exocytosis heterosynaptic facilitation Pre-synaptic mechanisms Neuromodulation 5-HT acts to enhance synaptic strength Short term sensitization of behaviour Short term, cAMP ↓S-type K+ channel ↑ excitability Ca2+ influx ↓delayed-rectifier K+ channel ↑ spike broadening Ca2+ influx Direct effect on secretory machinery Long term sensitization of behaviour Also involve cAMP Recruit mitogen-activated protein kinase (MAPK) to nucleus Recruit cAMP response element binding protein−1 Transcription factor CREB-1, binds to a cAMP response element (CRE) in the promoters of target genes Growth of new synaptic connections ↑Number of physical connections Double connections per sensory neuron: 1200 2600 ↑ Synaptic strength Also Inactivation of memory-suppressor genes DIAGRAM Compare and contrast the molecular biology of the learning behaviour of Aplysia with that of long term potentiation (ltp) of the hippocampus in vertebrates?
sexual selection and signalling
signals/where they come from? Origins in everyday actions/features that incidentally conveyed information to others and influenced their actions - e.g.: flight intention movements, fear responses, respiratory changes, displacement activities... e.g. origin in autonomic respiratory movements (great frigate bird) origin in autonomic fear response (spotted hyena) origin in displacement preening (garganey/mandarin ducks) Sensory exploitation - signals exploit existing attraction of receiver to e.g. particular kinds of movement or colouration
most aspects of our physiology and behaviour are rhythmic
sleep-wake body temp heart rate/blood pressure liver/kidney/lung function hormones mental ability (attention/concentration, reaction time, performance) most accidents at night Mice eat in response to light CLAMS: comprehensive laboratory animal monitoring system
non-calculated migration
small tortoiseshell butterfly makes short migrations in the same direction with respect to the sun's azimuth. They change habitats for performing different activities during the day. These movements are always non-calculated
why did anisogamy evolve?
small: motility, more big: provisioning, fewer primitive isogamy (same) > anisogamy consequences: Mean reproductive success of males and females is equal, but... the variance in success greater for males than females Male reproductive success increases with the number of successful matings Females, however, can increase their success only by producing more eggs Therefore males put their reproductive effort into mating effort, and females into parental effort... generally MALES COURT, FEMALES CHOOSE Female dispersion governed mainly by the distribution of resources, male dispersion by the distribution of females - females therefore become a limited resource for which males compete → mating systems Resource distribution + synchrony of mate availability determines the environmental potential for polygamy
olfaction in mammals
smell Detection of hazards, pheromones and food. Integrates with other senses - flavour. Odorants bind to specific sites on olfactory receptors. Glomeruli aggregate signals and transmit them to olfactory bulb, signals interact with parts of the brain responsible for smell identification, memory and emotion. Terrestrial organisms separate olfaction systems for smell and taste aquatic organisms single system odorants: must have some water solubility, sufficiently high vapor pressure, low polarity, some ability to dissolve in fat (lipophilicity). no known odorant of molecular weight greater than 294. practically infinite number of chemical compounds detected at very low concentrations. two nasal passages in humans - 2.5 square centimeters containing approximately 50 million primary sensory receptor cells. molecular basis olfaction in humans 1) odorants bind to receptors 2) olfactory receptor cells activated/send electrical signals 3) signals relayed via converged axons 4) signals transmitted to higher regions of the brain
avoidance behaviour in Paramecium sequence of events
stimulus, receptor current depolarisation Ca++ influx Ca++ accumulation, reversal activated Ca++ pumped out, reversal terminated swims backward whilst intracellular Ca2+ is high until restored AP transient increase in Ca2+ ciliary reversal transient backward swimming AP is graded w stimulus strength Anterior events at the sensory nerve terminal pressure > influx Ca+, decreased calcium ion permeability Vm > ECa > +Ve Stimulus depolarize Vm Ca2+-dependent rising phase CaV inactivation, and K+ efflux falling phase Propagate to end of paramecium and cilia In cilia, further Ca2+ influx elevate intracellular Ca2+ effects beating mechanism to effect reverse beating movement Recovery on cessation of AP and restoration of Ca2+I Consideration of ICa = gCa (Vm - ECa) Importance of cilia Escape predator (amoeba) posterior mechxnosensitive ionic events pressure > efflux K+, increased cation permeability Vm > Ek > -Ve Stimulus hyperpolarize Vm Consideration of ICa = gCa (Vm - ECa) Small change in gCa Larger change in Vm and driving force Vm - ECa Increase Ca2+ influx elevate intracellular Ca2+ sufficient to ↑ beating but not reverse movement Recovery on restoration of Vm and reinstatement of Ca2+ increased Ca2+ is also responsible for predator aversion: signal encoding DIAGRAM where are the ion channels Topologically distributed with respect to behavior Deciliation Vm still responds appropriately to anterior and posterior physical stimuli But no swimming, nor AP Why? behavioural ion channel mutants DIAGRAM TRANSDUCER > SENSORY PATHWAY > INTEGRATION > EFFECTOR PATHWAY > EFFECTOR (CILIA)
optimal prey choice in humans
summer canoe hunts canoe ptarmigan hunts jig/goose hunts prey types will be included in the optimal diet if they have an individual handling rate equal or greater than the overall rate which includes all higher ranked prey not always optimal- lake trout and exception, maybe taste/preserve better or extra nutrients
Social versus covert mating systems: extra-pair copulations
superb fairywren Cryptic polygamy - extra-pair copulations LEADS TO SPERM COMPETITION Indigo bunting less mating observed in within-pair copulations less copulation- fewer days before egg laying Blue tit - 31-47% of blue tit nests had extra-pair paternity and males did not exchange paternity at other nests. If a male was getting copulations in other territories, he was also getting the copulations at home. If not getting mates at other territories and not off visiting, the female is likely to be visiting other males. Males appear to be higher quality than males not gaining EPP Australian magpie lower extra-rate of paternity w higher freq (no. of spp.)
genetic basis for migratory behaviour?
test the adaptiveness of migration in three ways. Are the movements calculated? Is migratory behaviour heritable? Does it vary between species and can we model when it is likely to occur? Migratory direction is heritable in Blackcaps The F1 generation head in an intermediate direction to their parents. Not entirely based on experience. e.g. cuckoos, the young cuckoo is raised by other smaller birds and the adult cuckoos leave for Africa before they even fledge from the nest. The young cuckoos can migrate down to Africa the first time on their own, correctly. At least part of this behavior must be genetically based. blackcaps Migratory restlessness: 'Zugunruhe' artificially select for migration fave way to prove something has genetic basis 2 lines of blackcaps for level of migratory restlessness they showed at appropriate times of yr manifests in fluttering at bars of cages/flighty behaviour
when are signals honest?
whenever Sender is related to receiver - requires kin recognition mechanisms - template matching - can be learned or innate - requires cues with variation to permit estimation of relatedness - often involve olfaction and MHC (MHC is the Major histocompatibility complex, part of a set of genes that codes for immune function. Different MHC alleles give individuals different body odours. Individuals that share alleles have similar body odours) - familiarity with spatial location - treat all offspring in nest as own Signal production is condition dependent costs of signalling can only be borne by individuals in good condition
living in groups
why some grouped vs. solitary between/within spp. scenarios always individual's choice? e.g. meerkat subordinate females driven out by dom female cost benefit analysis optimality theory- optimal group sizes? e.g. yellow-eyed junco bird OFS = Optimal Flock Size shifting optimal group sizes with addition of other factors such as competitors when food availability drops and with the addition of a predator such as a hawk As the temperature increases food demand drops and birds can afford to compete more as there is more energy, so flock sizes decrease. When predators are present flock sizes increase. optimal group sizes may be inherently unstable
ideal free distribution e.g.
yellow dungfly Females arrive at the cow pats to mate and lay their eggs in the dung (called ovipositing). Males stake out females either in the grass near the pats or on the pats themselves. Once a male has mated with a female, but before oviposition, he sits on her back and guards her, while other males attempt to mate with her. Females are mobbed by males, sometimes even drowning in the liquid manure as the males stack up on their backs. Where should a male wait in order to secure the most females? Should he stake them out as they land in the grass to approach the pat or should he attack them when they are being mateguarded? zones downwind of the pat. When the pat gets too crowded, females land a little further away and walk to the pat. There are zones around the dropping where males are likely to capture females. Males compete to be in these areas. Males are likely to interfere with the mating opportunities of others, so, stay in a prime spot, or go further from the good spots where there are fewer males to interfere? Need to balance these competing factors out. The IFD predicts the distribution of the males, and this reflects the likelihood of successful mating. The observations fit the predictions very well, so male yellow dung flies follow the Ideal Free Distribution.
evolution of NS
~580mya Only animals that don't have nervous system are sponges and placozoa filter feed
Aplysia
• Aplysia • Gill withdrawal reflex when siphon is touched • Pacemaker - negative feedback, R15 works independently of neighbours controls rhythm • Cell membrane - Vm depolarises, crosses threshold • Voltage gated calcium channels, calcium comes in, hyperpolarising • Saturated, calcium leaves, depolarising Neuronal timing bursting: role of intracellular Ca2+ and neg feedback Vm crosses AP threshold Activate voltage-gated Ca2+ channels and Ca2+ influx Ca2+ -dependent AP terminated by voltage-gated K+ channels Accumulation of Ca2+ channels with successive APs Intracellular Ca2+ finally activates Ca2+-sensitive K+ channel to hyperpolarize Vm and terminate burst: negative feedback Intracellular Ca2+ recovers to basal, KCa closes, Vm repolarizes Cycle repeats
endogenous vs. exogenous
• Aschoff got subjects to live underground for weeks • Study w/ roaches - periodicity, no info from environment, innate rhythm but periodicity shorter than 24 hrs • Phase delay phase delay = 24hrs over 28 days 24/28=0.86h/day period=24.86h • Before you wake up- core body temp increases and plasma cortisol decreases in anticipation Free run in constant conditions, period ~24h, but normally synchronized ("entrained") by light and non-photic cues ("zeitgebers")
Study hormones, closely related spp. Where gene of interest is different
• California deer mouse strong paternal behaviour (grooms) and more AVP, common deer mouse v little paternal behaviour (will try to escape/attack young) • Monogamous prairie vole- many more oxytocin/vasopressin (more binding) receptors • Introduce stranger to pair bonded prairie voles- attack • Remember each other- social recognition, reject other voles evidence for causal link pharmacological: infusions of receptor antagonists block partner preference formation- OT-R (female) or V1aR (male) genetic: male meadow voles induced to overexposes V1aR in ventral palladium; increased pair bonding transgenic mice w V1aR ablated have a completely loss of social recognition IN MAN: polymorphisms in V1aR promotor linked to autism (inability to form social attachments) fMRI: activation of ventral pallidum when viewing sexually attractive image F increased oxytocin at orgasm M increased AVP during arousal
what if optimality fails?
• Consider simpler decision rules - e.g. fixed giving up time, fixed number • Include additional constraints - predation risk - minimum nutrient requirements - avoidance of toxins e.g. Macaws have to go and eat this special clay on one particular riverbank to counteract the effects of tannins and other toxins in the plants they eat. They must make time to visit this site and eat some of the clay or they cannot use those plant species as food. - starvation risk avoidance • Consider currency other than profitability - efficiency (Egained/Espent) alt currencies Nectar load that bees can carry shows diminishing returns because larger loads take more energy Data fit efficiency maximisation (Egained/Espent), not profitability Selection on hive rather than worker favours efficiency
Estrogen action in hypothalamus
• Estrogen action in hypothalamus • Preoptic area, rostral area of hypothalamus (courtship) vs. ventromedial hypothalamus (lordosis) • Implant estrogen • Estrogen receptors in preoptic important in soliciting courtship • Ventromedial more important for receptive behaviours • Estrogen also can act on membrane receptors • Estrogen as much a male hormone as a male one • Testosterone in brain in males converted to estrogen, bioactive steroid Limbic system > hypothalamus (oxytocin (OT) and vasopressin (AVP) from oestrogen > endocrine system