Evolution Midterm

What is the most amount of teeth found in a human mouth?

-232

How common are vision problems in humans?

-25% children -40% of those in 20s

What is methylation?

-A chemical reaction in the body in which a small molecule called a methyl group gets added to DNA, proteins, or other molecules -this addition can affect how some molecules act in the body (i.e. methylation of the DNA sequence of a gene may turn the gene off so it does not make a protein)

What is Batesian vs mullerian mimicry?

-B: something harmless mimicring something harmful (spp you're mimicking has to be more abundant than mimic otherwise predators will learn to risk it) -M: 2 noxious things mimicking each other

What is the CCR5 gene case study?

-CCR5 code for cell surface protein on T cells, the protein is used as a coreceptor by most strains of HIV1 -it has been found that an allele has a 32 bp deletion, resulting in non functional genes -individuals who are homozygous for the allele (delta 32), lack the protein, HIV cannot bind and they are IMMUNE to it -so regular/delta32 susceptible but progress to AIDS slowly and delta32/delta32 resistant -Ashenazi Jewish and Iceland showed significant resistance; Europe had most because bubonic plague (delta 32 works same against the plague to the plague selected for more Europeans to have delta32 and thus resistant to AIDS)

What are the theories about the transitional period between coming out of trees and being bipedal? (4)

-DARWIN (freeing of the hands for tools/weapons, likely wrong since bipedal occurred before tools appeared) -THERMOREGULATION (more likely to overheat on 4s since more sun exposure; also wrong since early hominids from forests/wet/humid places so sun exposure not really an issue) -AMPHIBIAN GENERALIST THEORY (bipedal due to wading; hominids descended from tree into marshes, wading apes needed to be bipedal to keep above water, water removed muscle strain of walking fully on all 4s, exp showed great apes dont fatigue when bipedal on water) -BIPEDALISM AND SEX (food issue when climate change, selection for males to provide for females and walk long distances; walk for sex)

Why can genes be expressed differently even if it's the same sequence?

-DNA wrapping around histones TIGHLY and needs to unwrap in order to transcribe and translate to express certain genes -you can control expression by adding methyl or acetyl groups on top of DNA (methyl locks down acetyl does opposite) -epigenome is ON TOP of genome, controls what gets expressed -ENVIRONMENT can affect epigenpme -epigenome marker can be passed on just like genes and can affect future generation phenotypes

How does lamarck and darwin's idea of evolution differ?

-Darwin suggested lineages branching and going extinct; Lamarck did not -Lamarck suggested species change and respond over time (i.e. giraffes stretch necks to reach leaves and offspring inherit this) -Darwin's idea is about changing form and number of species (longer neck giraffes have better fitness and actually get to reproduce and have offspring)

What is an allele?

-Different forms of a gene -adds the flavor of what the gene is coding for -different ones produced by MUTATIONS

What are 3 ways to study adaptations?

-EXPERIMENTAL (long tailed widowbirds have long tails, scientists gave the birds longer, regular, and shorter tails to see if long tailed male has more mates, females preferred lengthened tails so it was an adaptation for mating) -OBSERVATIONAL (looking at feather structure; no manipulation done) -COMPARITIVE (baculum size in pinnipeds, no manipulative, compared social structure)

What is the Hardy-Weinberg principle?

-IF mating is random across the pop, all genotypes have = success at surviving/reproducing (no selection), there is no migration (no gene flow), pop is large, and no mutation -THEN allele frequencies will not change from one gen to the next and population is in equilibrium (NO EVOLUTION)

Is all variation genetic? Why?

-NO -can be maternal (if her offspring does better if aggressive, she can allocate how much androgen she puts into eggs, she decides if she needs more help at nest or more breeders) -variation from epigenome -variation from environment

What is the unified theory of evolution?

-Neo-Lamarckian theory facilitates Neo-Darwinian theory -genetics and epigenetics both contribute to our molecular understanding of evolution (promote phenotypic variation that natural selection acts upon)

What is eusociality?

-One colony working towards the common goal of survival and reproduction -case of extreme cooperation and specialization -range from simple cooperation/cooperative breeding all the way to a caste system)

What are the rods and cones?

-Rods and cones are photoreceptors present in the retina -Rods are specialized for night vision -cones are specialized for daylight vision, fine visual acuity, and color -at back of eye and pointed to back; connects to nerves -light has to get past all neurons and picked up by photoreceptors

What was the story of Darwin and Alfred Russel Wallace?

-Wallace sent Darwin a manuscript about natural selection; wallace was moving faster -darwin got scared and rushed to publish their shared idea so he would get credit -Darwin's ideas not unique but he had so much DATA, which is why he is credited with these theories -objections to Darwin's ideas (not the idea of evolution but the MECHANISM because it went against church and discussed humans)

What is an adaptation?

-a characteristic that enhances the survival or reproduction of individuals that bear it

What is acetylation?

-a chemical alteration of the histone component of nucleosomes that is catalyzed by histone acetyltransferase enzymes (HATs) which makes promoter regions available for binding --> transcription -reduces affinity between histones and DNA; usually enhances transciption

What is a monophyletic group?

-a classification system in which taxa are described as groups species composed of common ancestor and all of its descendants

What are mutations?

-a consequence of unrepaired damage to DNA -SUBSTITUTIONS are fixed mutations -mutation does NOT always equal evolution

What are evolutionary trade offs?

-a favorable trait could incur costs on a different trait (mosquitofish with large gonopodium are more attractive but more susceptible to predation) -what might be good in one environment bad for another (pale skin helps in north for vitamin D but bad for cancer in tropical climate) -a trait that may be helpful during early life but bad later in life (can't be selected against when post reproductive, sex hormones) -heterozygote advantages (sickle cell/malaria; cystic fibrosis/typhoid)

What is branching evolution (cladogenesis)?

-a more rapid splitting of one or more new species from an original species that may or may not continue to exist -so one species branches into two or more new ones -this process is the basis for all biological diversity -sometimes called PUNCTUATED equilibrium

What is gradualism (anagenesis)?

-a slow gradual accumulation of heritable changes (adaptations) in a population due to many small episodes of natural selection -so one species changes slowly, step by step, until it looks so different we call it a new species

What is pseudocopulation pollination?

-a type of adaptation caused from natural selection -orchid plant looks and smells like the bee that pollinates it -males attempt copulation with flowers, but just end up pollinating it lol

What is spectral tuning?

-ability to modify peak wavelength that you see -refine what shades you see -bats can do this

What is fitness?

-ability to survive and reproduce -average lifetime contributions of a particular genotype to the population after one or more generations

Natural selection results in what?

-adaptations -natural (or artificial) selection is the ONLY MECHANISM known to cause the evolution of adaptations (this is how mimicry happens)

What did adult mammals do to their larynx/epiglottis?

-adult mammals moved voice boxes so the epiglottis seal is INEFFECTIVE -larynx lower in humans, well down the throat of an adult human (but behind tongue in infants) -low position let humans speak though (more vertical space above larynx lets sound be more meaningful) -birds have low syrinx (larynx equivalent) too which lets them talk

A peacock tail is an example of what in terms of natural selection?

-advantageous characteristics having a cost -large tails allow males to reproduce more (BENEFIT) but are also more prone to predators (COST)

Why did we evolve to walk?

-african changing habitat -growing brains and meat has higher calorie count to help this

What is natural selection?

-any consistent differences in FITNESS among phenotypically different individuals that gives variation that the environment can select -includes SEXUAL selection too -most important levels of selection are the individual and genes (but other levels possible)

How do cells function in an individual organism?

-as cells collect, like duplicated genes, some can specialize for different functions -more efficient this way -some people comsider this altruism -Pyrosome in a colonial tunicate, volvocines, and man o war are all examples

What is the cost-benefit analysis of carnivorous plants?

-as more nutrients is added from carnivory, the photosynthetic rates increase until they plateau -photosynthetic rates are higher and less likely to plateau in SUNNY and MOIST environments -carnivory evolves when profits exceed the costs (peak of higher dotted line)

Why is change gene frequency gradual?

-because most genetic variants have SLIGHT effects on phenotype -so takes longer

Why do we have knee problems?

-because we're BIPEDAL -more shock/weight distribution -menisci shock absorb in knee

What are the anatomical changes in the toes?/foot

-big toes positioned with rest of digits -early hominid foot (ardi) had opposable big toe but still bipedal (transition fossil) -this big toe orientation (along with narrow shoes) causes bunions -bulky heels (to take more impact) -thicker and tougher calcanei to wonder -heel strike for a long distance gait

Where do we have the best and worst vision in our eye?

-blind stop where lots of neurons in one area with no photoreceptors -we also get pits around back in which we pack rods (fovea) where we have sharpest vision

Why did some bats sacrifice vision for sound?

-broader ecological shift to eating insects or something else other than fruit -relaxed selection (vision less important so don't select for it)

The reaction norms of populations adapted to different environments may differ. How are caterpillars of swallowtail butterflies from Alaska and Michigan an example of this?

-caterpillars were obtained from these 2 different locations and grown in 2 temperature conditions -high temp stimulated growth -in cold temp, caterpillars from Alaska grow better under lower temps -example of phenotypic plasticity

What is evolution and what are some of its key characteristics?

-change in ALLELE frequency in a population or descent with modification (from common ancestor) -focuses on SPECIES/POP and NOT the individual -NOT intentional -generally favors functionality -long process in most cases

What is genetic drift? What are the 2 types?

-change in allele frequency due to CHANCE (not selection) -founder effect and bottleneck

What is microevolution?

-change in that POPULATION -ex: antibiotic resistance -enough of micro changes can lead to macroevolution over time

What does our increase in power output, VO2max, stem from?

-changes in our leg muscles -50% increase in size in these muscles

What are point mutations? What are the types?

-chemical changes in just one base pair of a gene -substitutions -synonymous -non synonymous -insertion or deletion (frameshift mutation)

What is the leading cause of accidental death across age groups? Why?

-choking -air tubes are narrower when younger and kids have trouble coughing -elderly also have trouble because the neurological hookup between brain and swallowing might be worse and cause issues with age

Systematics has evolved to be dominated by what?

-cladistics

Describe the SWS1 phylogenetic tree in the bat paper? Trends of echo and color vision?

-colorful letters represent amino acid sequences found in bat genome and their heights show what proportion of bats contain those amino acids in the position -red font has NO color vision, black DOES -fruit bats do no have laryngeal echo, tree roosters more likely to have low duty echo and color vision, cave roosters more likely to lack color and have high duty echo

Many evolutionary transitions share what?

-common structure

What were Ron Burton's intentions with his experiment involving small shrimp like animals?

-compare the genomes of isolated copepod populations -he sequenced the mitochondrial gene, cytochrome c oxidase, to ID species, and by mating the copepods to other populations and to each other to study the offspring survival -findings suggested isolated populations had genetic incompatability

What selection occurs between gamete and zygote stage?

-compatibility selection - gametes might not be compatible enough to create a zygote

How does color vision work? How does color blindness happen

-cones used to see color -mammals had to be active at might and hide during day to stay away from dinos and lost lots of color vision -diet drives it too (herbivores need to distinguish fruit) which is why we can still see greens well -color blindness driven by X chromosome which is why more men are colorblind (no extra X to fall back on)

Why is evolution important to study?

-conservation (allows us to assign value to spp based on how closely related) -ag (we have driven evolution through selective breeding) -medicine (evolution has given us unfortunate characteristics like bad knees/backs that require medical attention)

What is multicellularity? How do organisms get there and why?

-consists of more than one cell (duh) -how: staying together (clonal); coming together (non clonal; slime molds ex of this) -why: economies of scale (cheaper as you add more); allows specialization (then this leads to multicellular individuals rather than just groups of cells)

What are the 3 methods of evolution?

-convergent -coevolution -divergent

What are some vestigial characteristics?

-coocyx -wisdom teeth -pseudogenes (fake gene, once coded for something but no longer do) -i.e. icefish that does not have hemoglobin; has the genes for it but does not code for it

How did fire affect us?

-cooked meat easier to eat -we go less sick -cooked meat had more nutrients for the brain

What is neurogenesis/

-creation and development of neurons and glial cells

What is macroevolution?

-creation of a NEW species -the "stereotypical" evolution -ex: from dinosaurs to birds -enough micro evolution can lead to this

Describe the study in which santa cruz copepods crossed with those in san diego?

-crossing these 2 resulted in hybrids who did fine survival wise -when hybrids crossed with each other, offspring did NOT (slower development, low fecundity, low survival) -F1 hybrids have full set of n genes from each parent but F2 hybrids had mismatched in the parental genomes due to genetic recombination (potentially creates mismatch between the n and m genomes to affect fitness

What are gill arches?

-curved regions of tissue between the gills -became features of head and neck (inner ear bones) -they are where the larynx as a sphincter originated

What is relaxed selection?

-decrease or absence of selection pressure on certain trait -so those traits are no longer selected for and thus can be lost -nonfunctional visual genes associated with those and poor light; these genes believed to be lost through this selection -likely explains loss of function in SWS opsin

What is the mitonuclear species concept?

-defines spp by set of coadapted mitonuclear genotypes (spp defined by how their m and n genomes evolved and how compatible they are) -mating 2 ind who are outside the spp boundary will result in offspring with bad combos of m and n genes that will lead to poor mitochondrial function -same spp must be mitonuclearly compatable

What are some "nots" of adaptations? (3)

-differences between populations are not always adaptive -not every trait is an adaptation -not every (or any) adaptation is perfect

What are the 3 modes of natural selection?

-directional (one way or the other; darker mice selected over lighter) -disruptive/diversifying (nothing happens to the mean; extremes selected for; very light or very dark mice) -stabilizing (average; compresses variability; mid mouse favored)

Frequency dependent population tends to maintain what feature in a population?

-diversity

Populations evolve by changes in gene frequency which can happen by what? (3)

-drift -gene flow -natural selection

How is the human foot made for distance?

-elongation of Achilles heel (efficient at storing and releasing energy) -arch of foot (maintains rigidity and mitigates effects of the force and impact absorbed by walking on 2 feet; also acts as spring); people start life with flat feet and arches can fall to flat

What functions are improved with exercise?

-endorphin rush -grow more muscles mass -reduce inflammation -increase metabolism -increase lung capacity -better immune system (stronger and faster white blood cells) -helps sleep and neurogenesis -helps cardiovascular

What is the evolution of the lung?

-esophagus lies directly UNDER trachea -fish able to survive out of water used lung respiration when necessary (like when ponds dried up) -lungs emerged in limited groups of fish from outpocketing of the digestive system -swim bladder and lungs may have shared ancestry

What did Theodosius Dobzhansky comment on evolution?

-evolution fuels biology -biology only makes sense w/ evolution -he focused on genetics and genetic change before Watson and Crick figured out DNA

What were some conclusions of the exercise paper? (sorry this is a lazy question i know lol)

-evolution of exercise result of generations of changing cultures, physiology, norm, and bodies -while ancestors did not need to seek out exercise, we do; even standing good for circulation -the amount of exercise required to keep us healthy 10x that of ancestors -interesting exercise benefits: curbs cortisol, helps glucose regulation, clears fat from blood

What is piecemeal evolution?

-evolution that has occurred over stages, with ancestral and modern traits appearing simultaneously -our ability to exercise (S shaped spine, longer legs than arms, bowl pelvis, homo erectus traits, brain power; willing to travel to hunt more meat because selection favored higher protein diets that led to better brains)

What is a caste system?

-extreme specialization in which not all individuals can reproduce -like termites/bees; all but queen/males forgo reproduction of own in order to make sure mom successfully reproduces (fitness makes sense mathematically) -moles rats do this too

Describe resistance using aphids as an example. What is this an example of?

-farmer applies pesticide -kills off most susceptible aphids -resistant aphids will go on to reproduce -more and more resistant aphids born over time until most are resistant and pesticide is ineffective -example of EVOLUTION

What is exaptation (preadaptation)?

-feature that fortuitously serves a new function -feathers around for thermoregulation before flight evolved but now they use feathers for flight as well -hairs of porcupine used defensively as exaptation

What are the theories for why females in sports more likely to tear their ACL?

-female knee sits at different angle relative to hip -female skeleton has trade offs between best angle for bipedalism and child birth -individuals with SMALLER ACLS more likely to tear (and most women have smaller ACLs) -females have more erect landing posture which makes ACL more prone to tearing

What are the adaptations of human body for bipedalism? (3)

-femur angles inwards (knees and feet closer together in humans, makes efficient stride with less shifting weight, no waddling) -pelvis changes (issues to birth canal now) -S shaped human vertebral column holds head and torso above center of gravity so no issues tipping over

What are dicots? How does this relate to carnivorous plants?

-flowering plants; seed has 2 embryonic leaves -suction traps, lobster pot, bladderswort, flypaper, pitfall, pitcher plants, snap traps

What are the benefits of group living? (4)

-foraging in groups -increased protection from predators -ease of finding mate -ease of evaluating a mate

What is cooperative breeding?

-form of eusociality -males and other individuals in the group (offspring) help raise the young -mom and dad go to reproduce a second time), dad harasses older offspring and causes their nest failure in order to get them to come back and help raise younger siblings -parents do better this way because more related to offspring than grandchildren -some birds/mammals do this -might also do this if there is not place for offspring to nest (so instead you come back to help parents; better to have some success in siblings than a total nest failure)

What is the modern synthesis?

-fuses Darwinian evolution with Mendelian genetics -populations have variation from RANDOM mutation and recombination -populations evolve through changes in gene frequency by drift, gene flow, and natural selection -change is GRADUAL because most genetic variants have slight effects on phenotype -diversification (speciation) is due to gradual reproductive ISOLATION -over time, changes give rise to new taxa

What selection occurs between parents to gamete stages? (2)

-gametic selection )which eggs and sperm will be viable and join) -fecundity selection (if you have the ability to produce an abundance of offspring)

What is purifying selection?

-genes that are not good for species anymore are no longer selected for; getting rid of something no longer helpful to species -pseudogenization of SWS in some bats was example

What are the constraints on natural selection?

-genetic variation (selection can only act on this) -phylogenetic inertia (historical constraints; can only build on what is there; nat selection can only operate at the time and does not know the future) -pleiotropy (one gene may affect more than one trait; water retension good for desiccation bad for hypertension; high estrogen good for fertility but can cause cancer) -thrifty genes helpful for surviving famine, but also lead to diabetes and obesity

Mechanisms of evolution/patterns can result in more species diversity and can also make it challenging to figure out taxa. What can help this?

-genetics can help, but sometimes just another confusing bit of evidence

What is phenotypic plasticity?

-genotype that expresses itself differently in different environments (genotype expressing different phenotype) -ex: tanning, same spp of fish in fast moving stream have thin body shape vs those in slow stream do not -DIRECT response to environment

What is Dictyostelium discoideum? (slime mold)

-good for studying multicellularity -self sacrificing amoeba -they hunt bacteria but when foot runs out they stop eating/dividing and connect together -single ind releases AMP and they all come together -individuals start to specialize more in the group -weaklings sacrifice themselves and die off to create rigid wall for the being; it raises the survivors up to become spores and lifted away -you sacrifice because you have a better chance your genes (even in some of your clones) will be passed on (even though not ALL are clones)

What are monocots? How does this relate to carnivorous plants?

-grass like flowering plants; seeds contain one embryonic leaf -includes bromeliads (pitfall)

What is a polyphyletic group?

-groups that do not include a common ancestor -not considered to be a meaningful group -birds and mammals being called endotherms

What is a paraphyletic groups?

-groups that do not include all descendants -not considered to be a meaningful group -reptiles (since it does not include birds as well)

How is clonal fish an example of phenotypic plasticity?

-grown in different habitats, one in slow moving water, the other in fast moving -despite having the same genotype, they will have different phenotypes (body types) -fast moving ones are more streamlined, smaller gills, larger fins -slower moving ones are shorter, fatter, larger gills

What are some extant evolutionary relics for studying eye evolution?

-hagfish (simple retinas beneath layers of skin, suck as eyes; detect presence of absence of light which also set internal clocks; our eyes went from purpose of setting a clock to creating a whole image as they got more complex) -lamprey (cornea and lens both focus light onto retina)

Why is vision getting worse with generations?

-happening with nearsightedness specifically (myopia) -mainly because we are not getting outdoors enough because our vision success depends on natural light exposure

What are synonymous point mutations?

-have no effect on amino acid sequence -CCT and CCG code for same amino acid -just because you subbed nucleotides, there is no effect

What characteristics used to classify taxa? (8)

-hierarchical organization of life forms (linnean classification system) -homologies -embryological similarities -vestigial characteristics (remains of old characteristics) -convergence -suboptimal design -geographic distribution -intermediate forms (like the takaliik)

What is good and bad with Lamarck's theory?

-his theory of evolution talks about individuals, which isn't really how it works -not as wrong as we though though, some gained characteristics can get passed on in a lamarkian fashion (i.e. epigenetics)

Universal genetic code is an example of what?

-homologies

In sexually reproducing populations, the alleles combine in the diploid zygote to form what types of genotypes?

-homozygous -heterozygous

How does Bezz feel about human evolution?

-humans still have several kinks to work out in terms of evolution -due our evolution, we often have some health troubles (bad knees, teeth, eyesight, backs, etc) -he emphasized the importance of asking this WHY rather than just the how

Who were the hadza tribe?

-hunter gatherers in Tanzania -perform more physical activity in a day than american in a whole week -travel 3-5x more than apes -although a postal worker still takes more steps than them

Who are the Twa people?

-hunter gatherers in Uganda -ankles very flexible; do well climbing trees due to crazy high dorsiflexion (upward motion of bending the toes toward the shin) -climb because they rely on honey

What is allopolyploidy?

-hybridization -occurs when 2 different species reproduce often resulting in sterile hybrids -getting mule from horse x donkey -results in new species -more common in plants

What is the optimal group size?

-if you're by yourself you spend lots of time scanning, but this goes down with higher flock size -fighting increases as size increases -feeding initially low because you have to spend lots of time scanning -as you add more individuals, feeding can go up -feeding goes back down as you get even more because now there is fighting -so BEST is at the peak of feeding (more important factor)

Aggregation and specialization facilitates changes in what?

-in formation technologies -organism develop new and increasingly efficient way to deal with info

What is the Wallace line?

-in malaysia, there's a line in which animals differ on each side -you can separate sources of origin with that line -west of line is tigers, elephants, and other animals found in Asia -east were tree kangaroos, cockatoos, and other species found in Australia

Simplifications of adaptive radiation is often a result of what? Examples?

-increasing functional efficiency -legs of horses; used to have separate defined toes, now fused today (horse body got big and heavy and needed one strong foot bone) -ducks simplified caudal vertebrae, lost teeth, gained keeled sternum, and fused fingers from an ancestor

What happens if there is gene flow (migration)? Examples?

-individuals moving in or out of pop (unless new arrivals have same exact alleles, this will change frequency) -spread of pesticide resistance is an example of gene flow (treat pop w/ pesticides, survivors mate with non treated pops) -introgressive hybridization in finches is an example -tends to HOMOGENIZE neighboring populations

What can phylogenetic trees be used for?

-infer history of species evolution -enable us to describe past changes in genes, genomes, life histories, development, etc -can make conclusions regarding, ecology, etc

Why is it hard to get rid of a mutation in mitochondrial genome?

-it does not undergo recombination

How do teeth and jaw evolutions relate?

-jaws and teeth had separate evolutionary origins -so not co evolved which explains why they don't always fit together nicely -jaw got smaller and teeth did not

Some individuals give up there ability to reproduce independently to do what instead?

-join together to form a larger grouping that shares reproduction -this could apply to molecules, protocells, multicellular organisms, social groups -once they aggregate into higher level groupings, they can take advantage of economies of scale and efficiencies of specialization (a group can perform a task more efficiently than a lone individual; division of labor like pack of wolves) -multicellular communication (internal) -> external communication (language)

What are the purpose of eyelids?

-keep eyes from drying out on land -eyelids first found in amphibians -some animals have 3rd eyelid (extra pair of goggle for sleeping or fighting; hunting too since they can still see but not harm the eye)

How have we created speech?

-larynx low in throat; SVT 1:1 -tongue needs room for speech -lots of benefits that outweighs cost -early hominids likely not capable since face too long -early homo sapiens likely could not either until they got longer necks

What is the function of cytochrome c oxidase?

-later protein involved in ATP production -reduces oxygen to water

What do we need for clear vision?

-light needs to be directly on retina to be clear -far sightedness is when light focuses in front of retina and vice versa

Why is there water fluid around eye?

-light travels slowly through water so it's not the best for vision -our eyes evolved in water which is why we still have moisture here; this helped refraction problems in the ocean -fluid eyes kept light from bending again after bending from the water -lacrimal helps keep eyes wet for this (also remove irritants/debris, emotion, etc)

What is reversal evolution?

-loss of derived features -i.e. legless lizards/snakes reversal within tetrapods (also convergent reversal evolution in this example)

What is an indicator of evolution in early hominids according to the exercise paper?

-loss of large and sharp canine teeth

What is high vs low duty echolocation?

-low: echoes do NOT overlap -high: continuous, have longer pulses

How do mismatched between n and m genome occur?

-m DNA mutates, if it does not align perfectly with nuclear, there is a mismatch -M also mutates faster so more likely it will not align

What are some important points made in the mitochondrial genome paper?

-m genome and the n genomes mutating and evolving at different rates due to genetic recombination (happens as result of crossing over, this leads to new combination of alleles, and increased genetic diversity; leads to reproductive isolation, slowly started to rely more on n genome) -goal of paper is to provide education on both genomes and how they are significant to evolution

What happened after the K-Pg extinction in relation to teeth?

-mammals could now dominate, now active during the day -mammals filled even more niches so their teeth varied even more -they had different number and shape based on their needs

How is the mitochondrial genome inherited?

-maternally

What is VO2 MAX?

-maximal oxygen uptake -high levels indicate GOOD cardiovascular health

How does genetic drift affect natural selection?

-may interfere with action of natural selection -esp in small populations

What is autopolyploidy?

-meiotic error -following the failure of the reduction of meiosis, some gametes would be unreduced (2N) combined with normal gametes will result in 3N zygote; these individuals generally have reduced fertility; if one of their unreduced 3N gametes jonins with a normal one you get tetrapod (4N) (could also form by two diploid gametes) and these produce fine -many spp of plants/some fish, tree frogs do this -natural autoploids (alfalfa, peanut, potato, coffee); some common in plants than animals

Point evolution and alterations of single genes fall into what evolution?

-micro -macro requires accumulation of these changes

WHat happens if there is selection? How are peppered moths an example?

-might expect change in allele frequency and thus evolution -gen 1 of peppered moths were light colored to blend in with tree lichen, these were selected for; industrial revolution made soot collect on trees and then darker moths were selected for

What is the endosymbiotic theory?

-mitochondria were bacteria living inside eukaryotic cells and developed symbiotic relationships -mitochondrial get place to live while cell gets energy from them -mDNA and DNA happen independently -mitochondria same size and makeup of bacteria -circular DNA like bacteria -double membrane in mitochondria unlike most organelles

Which genome mutates faster?

-mitochondrial genome -because nuclear genomes have checks that do not let mutations take over -this genome also evolves 50x faster -this happens because m more susceptible to free radicals, divides more frequently, does not have same repair mechanisms, for every cell division m can replicate multiple times

Why do our feet suck now?

-more bones from when we had better flexibility (now this causes issues because they can break from harder impact) -striking of the foot hurts -weight distribution issue (more pounding from the bipedal form)

What is divergent evolution?

-most common -speciation due to behavior, temporal, reproductive isolation, geographic isolation

What is the mother's curse?

-mutations are harmful to males but benefit or neutral to females -not much confirmed evidence for it

What is sexual selection?

-natural selection arising through preference by one sex for certain characteristics in individuals of the other sex -females chose which males to mate with -male male competition: elk fighting with antlers over -female choice: deal with crazy courtship behaviors (bird of paradise; peacock); females use some characteristic to judge increases allele for that characteristic because females choose it

What are the costs of group living? (4)

-need to find more food and share it -parasite or disease transmission -more obvious to predators -competition

What is convergent evolution?

-no evidence of common ancestor but still analogous feathers do to similar selection pressures -i.e. insect and bird wing

How does isolation relate to evolution?

-no trait evolves in isolation -evolution of traits do not happen in a vacuum; something needs to happen -behavior like exercise becomes norm, physiology adapted to accommodate it -humans have evolved to be able to improve biology to exercise while retaining ancestral qualities -faster metabolism, fuel for physical activity, but also similar skeleton to Lucy

How do chimps, gorillas, orangutans, and humans compare for exercise?

-non humans lazy; burn equivalent of energy of less than 5K human steps per day; this would cause diabetes and heart disease in humans -primates do NOT have risk for cardiovascular disease due to lack of exercise though

What are some features of mutation rates?

-not all genes mutate at same time -mutation rates affected by environment (urban areas with high pollution=higher mutation in pop) -rate typically LOW and thus not major factor in evolution (other than source of variation) -most pleiotropic -random, NOT directed

What is the origin of a species in a nutshell? (4)

-observed OVERPRODUCTION of offspring; many born but few survive which there is a STRUGGLE for existence/competition because more individuals than can produced than can survive on limited resources -individuals VARY (if there is competition of resources then only favorable variants survive to reproduce; we have selection) -most variation is INHERITED -favorable variants have more offspring and increase in frequency (which changes the population over time)

Describe the inbred sea otter case study

-observed and expected number of heterozygous CA and AK sea otters -in both they expected 7-8% heterogeneity, CA was only half of that, AK had much higher heterozygosity -CA population more INBRED than AK population because CA went through hunting bottleneck

But why aren't mutations more common? Why aren't species more adaptable than they are? Wouldn't that be more advantageous

-of the many subs that can happen, many do not and others happen repeatedly -this indicates natural selection constrained by possible kinds of advantageous mutations (limited number of possible pathways that work)

What are the 2 menisci?

-one lateral toward outside and one medial to inside -medial is crescent shapes and not changing, 2 insertions, like chimps -lateral is variable; crescent shaped in humans with 2 insertions in tibia (ONLY primate with this); but some people have discoid which causes issues and is atavistic

What are the limits of mutations?

-only work on pre existing traits -may alter developmental processes but CANNOT alter developmental trajectories that do not exist (winged horses)

How did complexity of life develop? What were the major events?

-origin of self replicating molecules (heredity) -origins of first cells -eukaryotic cells -sexual reproduction -multicellularity -developmental complexity -evolution of groups (complex societies) -eusociality -Abiogenesis-> RNA-> DNA-> human evolution-> analogue media-> digital media

What is the vertebrate eye evolution?

-originally for underwater use -had to be adapted to land -this could explain why our eyes have issues

How did human teeth change to fit our move out of the trees?

-our diet changed from fruits and leaves to grasses and sedges so different teeth would be better -we got HUGE molars (grinding) for grasses/sedges -these large molars became root of our problem

What is assortative mating?

-over time the whole population allele frequencies might change -mating with similar characteristics -i.e. only blondes reproduce with blondes; red heads might disappear

What are opsin genes?

-photoreceptor genes -classified by wavelength sensitivity -SWS (short and violet) -OPN (long; red and green)

What can natural populations faced with a changing environment do? (4)

-physically move back to beneficial habitat -accommodate the altered environment with phenotypic plasticity (direct response to environment) -adapt to altered environment through genetic changes (longer term; ex: peppered moths) -go extinct (L+ratio)

What are different kinds of mutations? (2)

-point mutations -sequence changes from recombination (unequal crossing over; transposons in which chunk of chromosome moved elsewhere) -many result in pseudogenes

What does mitonuclear incompatibility cause?

-population drift

What is an open reading frame?

-portion of DNA that does NOT have a stop codon -important for gene to be complete and functional

Is the mismatch between jaws and teeth evolutionary or because we do not work our jaws when we're younger?

-probably both -so our teeth are bad -many believe there needs to be more experiments done

What are opsins?

-proteins that detect color -monkey has 2 types tuned to certain waves of light -we have a third -each opsin coded by 1 gene; gene for newer opsin sits next to older ones and are similar -old opsin genes was duplicated, mutation allowed it to detect different wavelengths -they implanted another opsin in a color blind monkey and it gained red-green color vision

Who was french naturalist Jean-Baptiste Lamarck?

-put forward the idea that species changed over time in 1809 (one of the first to do so) -his process was different from that imagined by Darwin 50y later -he suggested the idea of TRANSFORMISM

Our primate ancestors (and most animals) are what type of color blind?

-red green

Even populations capable of rapid evolution may face a high risk of extinction due to what?

-reductions in population size during the initial period of adaptation -if there is no evolution, density decreases to nothing over time -if there is, density decreases over time but then rebounds but they can also decrease to such a low density they cannot rebound even with evolution

What is the relationship between reliance on insect derived N and carnivorous plant structure complexity?

-reliance on N increases as carnivorous structures become more complex -4 genera of pitcher plants (juveniles have nonfunctional picthers and gain nutrients from soil and insects caught by older plants; functional pitchers retain all nutrients from prey) -bladderwort (new bladders do not hunt, functional ones retain 50% of nutrients from prey and water

Diversification (speciation) is due to gradual what among populations?

-reproductive ISOLATION

What are pseudogenes?

-resemble functional genes but are not transcribed

What is an example of inverse frequency dependent selection?

-right vs left mouthed fish -you need BOTH to prevent the big fish from adapting to protect their side that is more likely to be preyed upon (if more right mouths, big fish will evade/protect that vulnerable side) -the MORE you get of one form, the LESS successful they are -inverse is usually this balancing act

What are some mammal examples of adaptations? (rock pigeons, oxpeckers, desert rabbit)

-rock pigeons have hooked beaks (could be leftover from old adapation) -oxpeckers eat parasites off big mammals, once they eat tick they return to wounds and drink blood for water and protein -desert rabbit with large ears; helps regulate body temp; vasodilation blood vessels and dump metabolic heat to environment

How does night vision work?

-rods tell us presence or absence of light (they need to recharge too which is why it takes time to get accustomed to dark spaces) -better night mammals have INCREASED rod density -so less rods means more cones (we can see pretty good color as a result tho)

What are the 4 mechanisms of evolutio?

-selection -mutation -migration -drift

What is the difference between selection OF vs selection FOR?

-selection OF genes -selection FOR a feature -selection FOR one feature can lead to the selection OF something else on that same gene -this is why some alleles may hitchhike along with mutations that have a selective advantage

What is frequency dependent sexual selection?

-selection dependent on the frequency of an animal -seen in many cases of Batesian mimicry because the MORE noxious animals the MORE success the mimics will have

What is the highest type of inbreeding?

-self fertilization

Scientists hypothesized that bats would show evidence of loss of function throughout phylogenetic tree due to long history of nocturnality and development of echolocation. What did they do for the experiment?

-sequenced cDNA (reverse transcribed DNA; contains only coding sequences which lets you better see similarities of WORKING genes) of various bat species to determine how similar one species SWS1 gene was from another's; repeated for M/LWS opsin

What happens when there is non random mating?

-sexual selection -assortative mating

What selection occurs between adult and parent stages? (2)

-sexual selection (one gender or other might be choosing who to mate with; some individuals do not mate and do not became parents and their traits are selected against) -survival selection (whether or not they survive to become parents)

Most mutations are pleotropic. What does this mean? Example?

-sickle cell (mutation affects sequence of hemoglobin such that stress changes shape into sickle; also gives malaria resistance, so one mutation affects multiple things) -albinism (hair color, vision/eye color, digestive system all affected)

Many genes are members of gene families. What does this mean?

-similar in sequence, related in function -ex: hemoglobin a and b both code for hemoglobin but found on different chromosomes; olfactory receptors -families also include PSEUDOGENES

What is homoplasy?

-similar structure due to shared way of life -parallel evolution, reversal, and convergence

What is analogy?

-similarity due to convergent evolution -structures with different origins but same goal

What is homology?

-similarity resulting from common ancestry -divergent evolution

How has our respiratory tract evolution affected out sleep?

-sleep disordered breathing -our structure can lead to snoring or sleep apnea

What are the downfalls of being a small population in terms of evolution?

-small pops vary more in allele frequencies due to sampling effects from one generation to the next -often affected by inbreeding depression and genetic drift

Why is UV vision important to bats?

-some flowering plants reflect UB light, helps fruit and nectar eaters find them

Why do fruit bats have better color visions?

-some monochromatic some dichromatic -can see wide variety of shades to distinguish fruits

How do carnivorous plants prevent accidental prey capture?

-spatial and temporal separation -UV patterns -different attractants -vegetative reproduction

What is the biological species concept?

-species are groups of interbreeding natural populations that are reproductively isolated from other such groups -if you can reproduce and make fertile offspring you're a species

What is plantigrade locomotion? How does it compare to others?

-stable way to move, but lacks speed -digitigrade have heavier bones farther from ground and contact ground with metatarsals and use as a spring; good for speed and spring (humans can mimic this but leads to calf strain) -ungulates just contact ground with toenails and most of bones in lower leg which is good for long distance walking and being fast from time to time

Only selection results in adaptation. These adaptations can be? (3)

-structural -behavioral -physiological

Why aren't we the best at running?

-structure of feet/gait not most efficient for it -plantigrade locomotion (most of foot contacts ground) -instead we can better cover long distance walking -barefoot runners better at it (run with forefoot first and generate smaller collision)

Who is Darwin?

-studied natural history and geology -became volunteer naturalist on board HMS Beagle expedition to map and explore coast of south am.; saw galapagos islands inhabited by diverse group of organisms that differ from those found on the mainland -came up with theory of evolution and natural selection

What are strategies for asking interesting questions?

-study natural history -question conventional wisdom -question assumptions underlying hypothesis -draw analogies that transfer question from field to field or taxon to taxon

What are substitution point mutations?

-sub one nucleotide out for another -transition (purine-> purine or pyrimidine -> pyrimidine) -transversion (purine-> pyrmidine) -purine (A/G) is bigger than pyrimidine (C/T) -if subbing purine for pyrimidine, get weird bump in helix

What is SVT?

-supralaryngeal vocal tract -ratio of horizontal (lips to back of mouth) and vertical (back of tongue to larynx) -1:1 in human adults (babies have more like other mammals which is why they cannot talk as well)

Why are humans great at endurance?

-sweat glands, feet, lack of hair, breathe heavily while running -long legs, short toes

What is endosymbiosis?

-symbiosis in which one of the symbiotic organisms lives inside the other -used to explain both mitochondria and chloroplasts (and perhaps nucleus); these things living in cell and then became part of cell; there is also a large amount of migration of DNA from these organelles into the nucleus

What is the bottleneck?

-take whole population, shrink down to few individuals due to some random event -those left reproduce and rebuild population, which shifts alleles -ex: artificial selection in some hunting (go after elk with largest antlers which has made antlers smaller over time)

How do you measure relative fitness?

-takes a proportion of highest absolute fitness as reference -known as W -RATE OF GENETIC CHANGE depends on this type of fitness

What is the founder affect? Examples?

-taking subset of existing population and starting a new population with that subset elsewhere -distribution of O blood allele in native populations of the world reflects original settlements -PA Amish have high incidence of polydactyly (extra digits) -achromotostic (only see in shades of gray, over time that characteristic spread on the island since lots of founders had it)

Did teeth or jaw evolve first?

-teeth came first -came from dermal denticles (flat structures that toughened up the skin of fish or were pharyngeal teeth in throats)

What are the causes of changes in allele frequency?

-the drivers of evolution (selection, drift, gene flow, etc)

Not all phenotypic variation is genetic. Much is influenced by what?

-the environment -although how responsive a phenotype is to the environment is often genetic, plasticity indicates that individuals with the SAME genotype may have DIFFERENT phenotypes if they live in different environments

What is allele frequency? genotype frequency?

-the proportion of a particular allele in the gene pool -proportion of of genotype in the population

What is systematics/phylogenetics?

-the study of classifying organisms and organizing them

What are epigenetics?

-the study of how the environment affects how genes are expressed differently even if it's same sequence -environmental factors that alter the expression of genes (via DNA methylation, acetylation, etc) -AHRR gene and smoking, reversible epigenetics example

How did the change to land affect evolution of jaws and teeth?

-these changed too during this shift -they varied as they filled available niches -reduction in teeth -mammals no longer replace teeth through lifetime as dental lamina degrades -more teeth variety develops in mammals as diet varies

What are non synonymous point mutations?

-they change the amino acid (may or may not have much function effect) -subbing hydrophobic for hydrophilic will have more effect than hydrophilic for hydrophilic -more like to have an effect than synonymous

What do thigh muscles do for bipedalism?

-thigh muscles take on most cost of maintaining posture if crouched -our inward bend of femur puts pressure on cartilage, bones, and ligaments, so muscles do not fatigue super quickly

Evolution of sex ratio tends to be frequency dependent. How/why?

-this is an evolutionary stable strategy (strategy hard to cheat/break) -if few females in pop, you want to make MORE females; if fewer males you want to make MORE males -this will lead to more success of your genes

Sharks have a marble lens instead of a disk. How does this work?

-this means they have more lens, light travels further on the bend which makes up for lack of bend on the cornea -sharks instead move lens back and short to focus instead of using retractor muscles

Which F2 hybrids show the best fitness in the mitochondrial genome paper?

-those backcrossed to maternal line had better fitness

What is atavistic? How does it relate to knees?

-throwback traits which are rare -discoid lateral meniscus is this (develops as reversion to the ancestral form of the character rather than the modern form; this form is thicker and more prone to tearing) -2 copies of gene structures (old and new); old is usually inactive but still there; in some people the old one becomes active, rendering it atavistic -errors like this happen because of our huge code has to be pieced together so its easy to make a change -cells usually use the modern version of genes but sometimes can accidentally use the old variants

How have hands helped with evolutionary success?

-thumbs are stronger and longer, shorter fingers and larger thumb muscles to help with grip and flexibility -we can use hands for offense AND defense

What are reciprocal transplant experiments used for? Example?

-to determine if genetics or environment is more important in shaping a characteristic (introduce 2 organisms into the other's environment) -works for lizard growth rate (taken from NE and NJ; swap 2 lizard types and see how they grow; NJ lizards grown in NE did not grow as much as NE native lizard; NJ lizards have genetically fixed slow growth rate and cannot take advantage of the more abundant resources; NE lizards in NJ did far worse than normal; resources available for growth are consistently fewer in NJ so they did not get resources fast enough to support their growth rate; NE is a better environment for more resources)

What is the epiglottis?

-toilet seat that flaps over larynx during swallowing -allows for respiratory and digestive pathways -because of this, non human mammals have ability to eat and breath at same time -also allows us to drink milk from mammary glands -epiglottis pretty useless otherwise in humans

What is the newt's and snake's evolutionary trade off?

-too little TTX production in newt's (more likely to be eaten but produce more offspring); too much (less likely to be eaten but fewer offspring) -too little TTX resistance in snakes unable to eat toxic newts but higher crawling speed; too much (able to eat news but lower crawling speed)

What was the trade off discussed in the bat paper?

-tradeoff of losing UV sensitivity in exchange for higher duty of echolocation -paper accepted this theory

What is the larynx?

-transition between upper and lower airway -was present as sphincter closing off bag like lung in lobed fish -can expand and contract by soft tissue; create seal within air (CRITICAL adaptation so we can handle air AND food at once)

What is the Tiktaalik?

-transitional fossil between fish and tetrapods -neck and flat head -bears weight on finds -walked

How and why do modern humans run?

-trigger to run was climate change (less forest in Africa, humans had to travel further and faster for food) -homo appeared being able to travel long distances on foot -meat priority to help brain and fuel body so running was helpful for this

Describe the digestive/respiratory tract path? Also, how did breathing through the nose evolve?

-tube for air was borne out of tube for food -pathway to lungs crosses pathway leading to esophagus -mammals developed secondary palate separating nasal and oral cavities and losing amphibian traits -respiratory behind digestive tract at start but lungs are toward front of body so they must cross

What is coevolution?

-two different spp evolve together (mutualism) -insect and flower evolving together for example (as flower gets deeper, insect mouthparts get longer -can also refer to developing resistance to a pathogen

What is a frameshift mutation?

-type of point mutation -insertion or deletion of a single base pair -usually disruptive, resulting in nonfunctional gene

From where on the body did modern teeth originate?

-unsure for sure, there are 2 theories -inside out hypothesis: teeth arose in pharyngeal cavity and migrated up into oral -outside in: dermal denticles/skin teeth migrated around and into the oral cavity

What is echolocation?

-use of sound to bounce off objects to get image of environment -sending out is pulse, receiving is the echo

What is the tapetum lucidum?

-used in nocturnal animals -reflects light back to photoreceptors (causes blue reflection thing/eye shine on deer)

What selection occurs between zygote and adult stage

-viability selection -you might not get to an adult stage -you might see the organism get born (initially successful zygote, but then not survive) -or you might become sterile adult

What is the retina?

-want to focus light on this -light hits cornea, hits lens, lens bends light, hits back of lens which bends it back other direction, hope 2 beams of light hit each other causing good vision

How do dinos/birds compare to humans for evolutionary anatomy?

-we both freed forelimbs to use -transition from quadrupedal to bipedal

How did our scavenging and meat eating behavior affect us?

-we used tools because our teeth weren't super adapted to eating meat -we needed intelligence to hunt which selected for larger brain and social capacity -intelligence/brain size kept in check by size of birth canal -selection for jaw DECREASED, so jaws got smaller and smaller but teeth didn't change (got even weaker with ag production which could make gruel for those with poor teeth)

Carnivorous plant thrive in what types of environments?

-well lit -nutrient poor -waterlogged -brighter areas attract larger pollinators; decreases prey pollinator conflict -nutrient low soil forces plants to turn to insects for nutrients (like nitrogen) -bigger pollinators in sunny areas also means bigger source of nutrients -damp areas dilute nutrients and attributes to nutrient poor soil so its efficient to be carnivorous in these areas

What happened when copepods were backcrossed to F0 in paternal vs materal?

-when F2 crossed with paternal line, m types do not match and no improvement -when crossed with maternal, same m type so improved fitness -backcross in maternal direction reintroduces the n genome to the mitochondrial background it is co adapted with

What are irreversible developmental responses? Examples?

-when conditions persists for long period, the environment may influence development and modify characteristics of the individual for long periods (even for the remainder of its life) -water fleas (grown in water with chemicals that indicate predatory fish; develops long spiky tail and head; those grown in regular water did not) -grasshopper color (changes color based on type of season to match background; rainy/low intensity light, high humidity are green, opposite are brown, those following dry season burning burning/low surface reflection are black)

What is a community?

-when different species cooperate with each other -meerkats grooming warthog, cleaner shrimp for fish, community of african mammals at watering hole -relationship in which ALL players benefit

What are our modern feet used for?

-work as shock absorbers (used to be for agility and flexibility when we were arboreal) -foot less flexible, absorb compound -ankles not flexible enough for scurrying up a tree

What are the features of natural selection? (3)

1) Individual variation: Members of a population vary in inherited traits. 2) Competition ("struggle for existence"): Species produce more offspring than the environment can support. Many offspring fail to survive and reproduce. 3) Unequal survival and reproduction ("survival of the fittest"): Individuals with advantageous traits will leave more surviving offspring. This leads to accumulation of favorable traits over the generations.

How do you measure absolute fitness?

A(R)= (proportion of offspring that survive to reproduce) x (average fecundity) -usually looks at females only

What is the inbreeding coefficient (F)?

F=(He-Ho)/He He- expected heterozygosity Ho- observed -quantifies the likelihood that 2 alleles of a gene in an animal are the same because they are descended from the same copy of the allele in an ancestor -if F=1 ALL individuals are homozygous and identical -if F=0 NO individuals has 2 alleles from a common ancestral copy -in a completely random mating pop the expected and observed levels of heterozygous individuals will be equal so F=0 (more fit) -inbred pops have LOW fitness -inbreeding depression is a measure of that loss of fitness