BIO EXAM 3

Major Annelidan Groups

Errantia -Long setae on footlike parapodia -Most are free-ranging predators -Well-developed eyes, powerful jaws -Often brightly colored Sedentaria -Setae close to body wall to facilitate anchoring in burrows -Tube worms •Marine, filter food from water with crown of tentacles -Earthworms •Condition soil through burrowing and feeding (castings) -Leeches •Primarily freshwater, generally blood-sucking external parasites, hirudin (anticoagulant) may be used in reattachment surgeries

`Subphylum Trilobita

Extinct early marine arthropods Bottom feeders Three main tagmata (head, thorax, and tail) Three longitudinal lobes Little specialization of body segments

Spiders

Fangs (chelicerae) are supplied with venom from poison glands •Partially digest prey in place by injecting digestive fluid Abdominal spinnerets produce silk •Used to wrap prey, construct egg sacs, and spin webs

explanations for the cambrian explosion

Favorable environment - warm temperatures, increases in atmospheric and aquatic oxygen, development of ozone layer Evolution of the Hox gene complex (allows more variations in morphology) An evolutionary "arms race" Example: Class Placodermi versus Class Chondrichthyes

demography

For many long-lived animals, it is impractical to follow a cohort from birth to death Life tables Data on the number of individuals alive in a particular age class Males are usually not included example: North American beaver 1964-1971, Canadian trappers provided mandibles Teeth extracted for age classification

logistic growth

For most species, resources become limiting as populations grow Causes per capita growth rate to decrease Carrying capacity (K) - upper boundary for population. It is the sustainable amount of population that can an environment can hold. The number of births = number of deaths.Growth pattern in which a population's growth rate slows or stops following a period of exponential growth

Aves: The Birds

Four features unique to birds (for flight): 1.Feathers - modified scales keep birds warm and enable flight 2.Air sacs - very efficient breathing 3.Reduction of organs - single ovary, no urinary bladder or teeth 4.Lightweight skeleton - thin, hollow, honeycombed •Enlarged sternum to anchor flight muscles

logistic growth example

K= 1000, N= 900, r=0.1 (0.1)(900) x (1000-900)/1000 = 9

Subphylum Cephalochordata

Lancelets 26 species All marine filter feeders Has all 4 chordate characteristics Gas exchange across body surface Usually sessile but can leave burrow and swim

carrying capacity

Largest number of individuals of a population that a environment can support K

Members of the family Hominidae.

(A) Gorillas, the largest of the living primates, are ground-dwelling herbivores that inhabit the forests of Africa. (B) Chimpanzees are smaller, omnivorous primates that also live in Africa. The chimpanzees are close living relatives of modern humans. (C) Humans are also members of the family Hominidae. The orangutan is also a member of this group.

Primate classification. Many authorities divide the primates into two groups:

(a) the strepsirrhini (smaller, nocturnal species such as this bush baby), and the haplorrhini (larger diurnal species). Haplorrhini comprise (b) the monkeys and tarsiers, such as this capuchin monkey (Cebus capucinus), and (c) the hominoids, species such as this white-handed gibbon (Hylobates lar).

Phylum Chordata

1.Notochord 2.Dorsal hollow nerve cord 3.Pharyngeal slits 4.Postanal tail •Chordate characteristics. The generalized chordate body plan has four main features: notochord, dorsal hollow nerve cord, pharyngeal slits, and postanal tail. NOTE: All chordates exhibit all four characteristics at some time during development

limitations of the mark and recapture method

Animals may learn to avoid traps Recapture rate will be low, results in overestimate of population size Some animals can become "trap-happy", especially if baited with food Results in underestimate of population size Other methods Antennal tracking of fitted radio collars Obtaining pelt records from trading stations Examination of catch per unit effort Counting fecal pellets, singing individuals, or leaf damage

Animals in Segmentation

Annelids, arthropods, and chordates all exhibit segmentation. Keep in mind that segmentation first appears in annelids.

Phylum Annelida

Approximately 15,000 described species Earthworms, leeches, free-ranging marine worms, and tube worms Rings are segments separated by septa Advantages of segmentation: 1.Repetition of vital structures provides backup (if one segment is damaged, the organism can still survive) 2.Coelom can act as hydrostatic skeleton without distortion of body 3.Permits specialization Locomotion more efficient

Bilateria (bilaterally symmetric)

Can be divided along a vertical plane to produce two halves Have cephalization and dorsal and ventral sides

´Radiata (radially symmetric)

Can be divided equally by any longitudinal plane through the central axis Often circular or tubular in shape, with a mouth at one end

coelom

Cushions internal organs Enables movement and growth of internal organs independent of the body wall Functions as a hydrostatic skeleton Muscle contractions push fluid from one part of the body to another Fluid acts as a simple circulatory system

metamorphosis

Developmental phenomenon in which animal changes from a juvenile to an adult form Reduces competition and facilitates dispersal

density dependent factors

Mortality factor that varies with population density Predation - Predators kill few prey when the prey population is low, more prey when the population is higher Competition - Increased competition for scarce resources reduces offspring production and survival Parasitism - Parasites pass to new hosts more easily as population density increases Detected by plotting mortality against population density and finding positive slope

global population growth

Most estimates propose global human population will grow to between 10 and 11 billion by middle of 22^nd century Total fertility rate - average number of live births a woman has during her lifetime Differs considerably between geographic areas Global TFR declined from 4.47 in 1970s to 2.52 in 2010 2.3 needed for zero population growth Replacement rate varies globally 2.1 in developed countries Between 2.5 - 3.3 in developing countries Why is this the case?

survivorship curve

Plot of numbers of surviving individuals at each age Generally use log scale to make it easier to examine wide range of population sizes Beavers show a fairly uniform rate of decline The survivorship curve is generated by plotting the number of surviving individuals, nx, from any given cohort of young, usually measured on a log scale, against age. This survivorship curve shows a fairly uniform rate of decline through time.

Fiorito and Scotto's Experiments

Showed Invertebrates Can Exhibit Sophisticated Observational Learning Behavior Octopuses trained to attack red or white ball using classical conditioning (reward and punishment) Octopus are color blind - so must see relative brightness of balls Observer octopuses watched trained octopuses attack ball Observers learned faster than original training

Subphylum Chelicerata

Three living classes •Arachnida (Spiders, scorpions, ticks, and mites) •Merostomata (horseshoe crabs) •Pycnogonida (sea spiders) Two tagmata - cephalothorax and abdomen Six pairs of appendages •Chelicerae •Pedipalps •Walking legs (four pairs)

Subphylum Urochordata

Tunicates - animal encased in tunic 3,000 marine species Adult is sessile with only pharyngeal slits Larvae tadpole-like, exhibiting all 4 chordate hallmarks Closest living relatives of vertebrates -Cephalochordates more closely related to echninoderms May be colonial or solitary Filter feeders with two siphons Rudimentary circulatory system Simple nervous system Mostly hermaphroditic

How population grow

Two types of simple models for population growth, based on whether resources are limiting Exponential growth - resources not limiting, prodigious growth Logistic growth - resources are limiting, limits the amount of growth

Indicate the idealized survivorship curve being described: A songbird species which the chance of death is equal throughout its lifetime.

Type 2

Three Survivorship Curve Patterns

Type I - rate of loss of juveniles low and most individuals die later in life Many large mammals, such as humans (survive for long time) Type II - fairly uniform death rate Beaver example, birds, reptiles, and some annual plants ( average) Type III - rate of loss for juveniles high and then decreases as the survivors age Many fishes, marine invertebrates, insects, and plants (die in young age, and then older you get you last) Survivorship curves show the distribution of individuals in a population according to age. Humans and most mammals have a Type I survivorship curve because death primarily occurs in the older years. Birds have a Type II survivorship curve, as death at any age is equally probable. Trees have a Type III survivorship curve because very few survive the younger years, but after a certain age, individuals are much more likely to survive.

Which characteristics are included in the Lophotrochozoan grouping? Check all that apply.

a crown of tentacles. trochophore larvae.

Lancelets.

a) A bladelike lancelet. (b) The body plan of the lancelet clearly displays the four characteristic chordate features.

metazoa

all animals

Quantifying Population Density

area must be small and organisms large quadrats and line transects - sessile species traps - more mobile species

calculating per capita growth rate

change in numbers/ change in time = birth - deaths

inverse density dependent factor

decreases with increasing population size Example: A territorial predator that kills the same number of prey regardless of population size.

Classify the following situation as a density dependent, inverse density dependent, or density independent mortality factor: As a heron population grows, competition for food and nesting sites reduces offspring survival.

density dependent

evolution of vertebrate jaw

developed from anterior gill arches Primitive fishes and extant jawless fishes such as lampreys have nine cartilaginous gill arches that support eight gill slits. (b) In early jawed fishes such as the placoderms, the first two pairs of gill arches were lost, and the third pair became modified to form a hinged jaw. This left six gill arches (4-9) to support the remaining five gill slits, which were still used in breathing. (c) In modern jawed fishes, the fourth gill arch also contributes to jaw support, allowing more powerful bites to be delivered.

What factors are examined by the field of demography? Check all that apply.

distribution of ages in a population birth and death rates in a population population size

´Eumetazoa

divided by symmetry

Radiata

do NOT form a mesoderm because they only have two layers

asymmetrical

does not have any lines of symmetry, ex: sponges

Bulk feeder (humans)

eating large food pieces

When a population is provided unlimited resources, the population will grow ______________.

exponentially

aquatic species

external fertilization

All nonradiate animals, including the sponges, display bilateral symmetry. True or False?

false

The epidermis, mesoglea, and gastrodermis represent the triploblastic condition found in all cnidarians. True or False? True False

false

Suspension feeding

filtering particles from surrounding water

vertebrate evolution

fishes were the first ones plants colonized land around the same time life on land presents important challenges reptiles dominated the earth for millions of years ago

Phylum Platyhelminthes

flatworms first with active predatory lifestyle bilaterally symmetrical with cephalization no resp. or circulatory system incomplete digestive system gastrovascular cavity

coelom

fluid-filled body cavity

mollusk body plan

foot-used in movement visceral mass - contains organs mantle - secretes a shell (if present) gills housed in mantle cavity coelom confined to a small area around heart open circulatory system heart pumps hemolymph (similar to blood) •Metanephridia remove wastes •Nervous system may be simple or sophisticated (octopus) •Radula - unique tongue-like organ (can be modified into a beak) Most shells have three layers secreted by mantle Separate sexes (some hermaphroditic) Mostly external fertilization -Some internal (key to snails colonizing land) Trocophore larva develops into veliger with rudimentary foot, shell and mantle

A mollusk with a coiled shell is most likely in the class ____________.

gastropoda

Radiata Cont.

gastrovascular cavity - extrecellular digestion , allows ingestion of large food tentacles surrounding the mouth for feed detection and capture true nerve cells arranged in a nerve net interconnected nerve cells with no central control organ

endoderm

gives rise into digestive tract

Marsupials

have a brief gestation and give birth to tiny, embryonic offspring, that complete development while attached to the mother's nipples.

Density Independent Factors

influence is not affected by changes in population size or density physical factors - weather, drought, flood, fire

Terrestrial Species

internal fertilization

Density -

number of organisms in a given unit area or volume Knowledge about population growth and density help us make species management decisions

The hinged jaw seen in the gnathostome vertebrates developed from the ___________________ that help support the ______________ tissues.

pharyngeal arches; respiratory

radiata

phylum cnidaria- jellyfish, box jellies, hydra, coral, sea anemonies phylum ctenophora - comb jellies radial symmetry mostly marine, some freshwater diploblastic bc of the two germ layers ectoderm and endoderm mesoglea to connect the layers

parazoa

pore bearers sponges do not have true tissues no endo,meso,ectoderm asymmetrical adult sessile larvae free-swimming

During the Cambrian Explosion, the evolution of Hox genes is thought to have assisted rapid speciation because ______ changes in the expression of Hox genes lead to ______ variation among certain important morphological traits.

simple, large

parifera

sponges

Population ecology -

studies factors affecting population size and how they change over space and time Uses the tools of demography - birth rates, death rates, age distributions, and sizes of populations

Fluid Feeding

sucking sap or animal body fluids, like a mosquito

The division of animals as radial or bilateral is based on each group's body __________.

symmetry

classification

symmetry

Phylum Platyhelminthes Cont.

predatory or parasitic excretory system with protoenphridia and flame cells may have ocelli cerebral ganglia receive input retain nerve net with beginning of more centralized nervous system asexual or sexual reproduction

parazoa

without tissues or organs

Human evolution

•About 6 mya in Africa, lineage split from other primate lineages •Evolution not a neat progression •1 or 2 hominin species coexisted at the same time •Key characteristic was bipedalism -Resulted in many changes - spine sits underneath skull, broader pelvis, lower limbs larger Sahelanthropus tchadensis - earliest known hominin

Birds are feathered reptiles with adaptations for flight

•Birds typically display very complex behaviors, particularly during breeding season. Courtship often involves elaborate rituals.

Comparing the Human and Chimpanzee Genetic Codes

•Chimpanzee Sequencing and Analysis Consortium published the chimpanzee genome in 2005 •Human and chimp genomes differ by only ~1.23% - 10 times less than those of mice and rats •Many differences result from chromosome inversions and duplications •Differences may explain why humans susceptible to some diseases chimps are not , as well as development of human speech May have been interbreeding after initial split

Amniotes: Tetrapods with a Desiccation-Resistant Egg

•Critical innovation was the development of a shelled egg •Amniotic egg broke tie to water •Shell is permeable to oxygen and carbon dioxide •Birds - hard and calcareous •Reptiles - soft and leathery •Most mammals - embryo embeds in uterine wall

Crocodilia

•Crocodiles and alligators •Essentially unchanged for 200 million years •Like birds, crocodiles have a 4-chambered heart, teeth in sockets, and care for young

Other key innovations of the amniotes

•Desiccation-resistant skin -Contains keratin •Thoracic breathing - negative pressure sucks air in •Water-conserving kidneys - concentrate waste prior to elimination •Internal fertilization

Additional features of some mammals

•Digest plants using cellulose-digesting bacteria •Have horns or antlers -Horns - permanent bony outgrowth surrounded by keratin -Antlers - composed entirely of bone, shed and regrow

Dinosaurs

•Dominant ~ 215 to 65 mya •Class Ornithischia - bird-hipped dinosaurs •Class Saurischia - lizard-hipped dinosaurs •Legs positioned directly under the body •Some may have been endothermic

Gnathostomes:Jawed Vertebrates

•Earliest-diverging gnathostomes were fishes •Jaws allowed more efficient prey capture •Accompanied by development of two pairs of appendages •Hinged jaws developed from gill arches (pharyngeal) •Two pairs of gill arches were lost, others were modified

Additional features of birds

•Endothermic -Ensures rapid metabolism and quick production of ATP •Warm body temperature (40-42°C) •Double circulation with 4 chambered heart •Acute vision •Most are carnivores •Wide diversity of beak forms •Eggs are brooded •Complex courtship rituals oMany variations in species: 28 orders, 166 families, 10,000 species

Mammals: Milk-Producing Amniotes

•Evolved from amniote ancestors earlier than birds •Appeared about 225 mya •Evolved from small mammal-like reptiles •After dinosaur extinction mammals flourished Range of sizes and body forms unmatched

Class Gastropoda

•Gastropods are the largest group of molluscs and include the snails and slugs. Gastropods are •found in fresh water, salt water, and terrestrial environments, •the only molluscs that live on land, using the mantle cavity as a lung, and •often protected by a single, spiral shell. •Slugs have lost their mantle and shell. Sea slugs have long, colorful projections that function as gills.

The nautilus

(a) A longitudinal section of a nautilus, showing the coiled shell with many chambers. The animal secretes a new chamber each year and lives only in the new one. (b) The chambered nautilus (Nautilus pompilius).

Exponential growth following reintroduction of a population into a habitat.

(a) A population of tule elk (Cervus elaphus nannodes) reintroduced to Point Reyes National Seashore in 1978 fits a pattern of exponential growth. (b) Black-footed ferrets (Mustela nigripes) reintroduced to Shirley Basin, Wyoming, since 2000. No survey was conducted in 2002.

Theoretical age distribution of two populations of gumbo limbo trees in the Florida Keys.

(a) Age distribution of an island with no Key deer with numerous young trees, many of which die as the trees age and compete with one another for resources, leaving relatively few big, older trees. (b) Age distribution of a forest where overgrazing by Key deer has reduced the abundance of young trees, leaving mostly trees in the older age classes

Tunicates

(a) Body plan of the sessile, filter-feeding adult tunicate. (b) The larval form, which shows the four characteristic chordate features, has been proposed as a possible ancestor of modern vertebrates. (c) The blue tunicate, Rhopalaea crassa

Common arachnids.

(a) Female black widow spider (Latrodectus mactans). (b) The Central American black scorpion (Centruroides gracilis) is highly venomous and carries its white young on its back. (c) SEM of a chigger mite (Trombicula alfreddugesi) that can cause irritation to human skin and spread disease. (d) These South African bont ticks (Amblyomma hebraeum) are feeding on a white rhinoceros.

Diversity among mammals.

(a) Prototherians, such as this duck-billed platypus (Ornithorhynchus anatinus), lay eggs, lack a placenta, and possess mammary glands with poorly developed nipples. (b) Metatherians, or marsupials, such as this swamp wallaby (Wallabia bicolor), feed and carry their developing young, or "joeys," in a ventral pouch. (c) Gestation lasts longer in eutherians, and their young are more developed at birth, as illustrated by this young langur monkey (Presbytis entellus).

Sampling techniques.

(a) Quadrats are frequently used to count the number of plants per unit area. (b) Pitfall traps set into the ground catch wandering species such as beetles and spiders. (c) Mist nets consist of very fine mesh to entangle birds or bats. (d) Baited live traps catch terrestrial animals, including this lion tamarin, Leontopithecus rosalia, in Brazil.

Mammalian hair.

(a) The sensory hairs (vibrissae) of the walrus (Odobenus rosmarus). (b) The camouflaged coat of a bobcat (Lynx rufus). (c) The defensive quills of the crested porcupine (Hystrix africaeaustralis).

Cartilaginous fishes.

(a) The silvertip shark (Carcharhinus albimarginatus) is one of the ocean's most powerful predators. (b) Stingrays are essentially flattened sharks with very large pectoral fins. (c) Close-up of the mouth of a sand tiger shark (Carcharias taurus), showing rows of teeth. (d) This mermaid's purse (egg pouch) of a dogfish shark (Scyliorhinus canicula) is entwined in vegetation to keep it stationary.

Features of the bird wing and feather

(a) The wing is supported by an elongated and modified forelimb with three extended fingers. (b) Each feather has a hollow shaft that supports many barbs, which, in turn, support barbules that interlock with hooks to give the feather its form. (c) The bones of a pelican (Pelicanus occidentalis) are hollow but crisscrossed with a honeycomb structure that provides added strength

The primates share several characteristics, which distinguish them from all other mammalian orders. Check all of the unique features that one would use to classify members into this order.

-Grasping hands with opposable thumbs -Large brain -Some digits with flat nails (not claws) -Binocular vision -Complex social behavior and well-developed parental care

If a rabbit population of 1000 has 100 births and 50 deaths per year, then population increases by 50

0.10 x 1000 - 0.05 x 1000 = 50 (0.10 - 0.05)1000 = 50

Human Populations can Exist at Equilibrium Densities

1.High birth and high death rates This was often the case before 1750, with high birth rates offset by deaths from war, famine, and epidemics 2.Low birth and low death rates In Western Europe, beginning in the 18th century, better health and living conditions reduced the death rate Eventually, social changes such as increasing education for women and marriage at a later age reduced the birth rate

classification of body plans

1. different tissue types 2. body symmetry (asymmetrical, radical, bilateral) 3. embryonic development

Cambrian explosion

A burst of evolutionary origins when most of the major body plans of animals appeared in a relatively brief time in geologic history; recorded in the fossil record about 545 to 525 million years ago.

Sessile

An organism that does not move. It remains attached to one place. Usually are not like this forever.

mark-recapture method

A sampling technique used to estimate wildlife populations. Animals are marked with tag or other system so they are recognized when captured again Mark and recapture is used to measure the population size of mobile animals such as (a) bighorn sheep, (b) the California condor, and (c) salmon. (credit a: modification of work by Neal Herbert, NPS; credit b: modification of work by Pacific Southwest Region USFWS; credit c: modification of work by Ingrid Taylar)

Annelid Body Plan

All annelids except leeches have setae on each segment May be situated on fleshy parapodia Leeches have suckers on anterior and posterior ends Giant axons facilitate rapid response to stimuli Double transport system Circulatory system and coelomic fluid both carry nutrients, wastes and respiratory gases Complete digestive system that is unsegmented Sexual reproduction involves two individuals (sometimes separate sexes, others hermaphroditic) with internal fertilization Asexual reproduction by fission

Exponential population growth

As the value of r increases, the slope of the curve gets steeper. In theory, a population with unlimited resources could grow indefinitely.

The ___________ of an amniotic egg surrounds a cavity into which waste products from the embryo are excreted. A. amnion B. allantois C. yolk sac D. chorion

B. allantois

For small sessile organisms, ecologists frequently use a ________, which is a small square frame that is used to standardize the area being measured. A. mist net B. quadrat C. sector D. pitfall trap

B. quadrat

A variety of bird beaks.

Birds have evolved a variety of beak shapes used in different types of food gathering. (a) Hyacinth macaw (Anodorhynchus hyacinthinus)—cracking. (b) White pelican (Pelecanus onocrotalus)—scooping. (c) Verreaux's eagle (Aquila verreauxii)—tearing. (d) American avocet (Recurvirostra americana)—probing. (e) Anna's hummingbird (Calypte anna)—nectar feeding. (f) Roseate spoonbill (Platalea ajaja)—sieving.

Class Bivalvia

Bivalves include clams, oysters, mussels, and scallops. Bivalves have shells divided into two halves that are hinged together. Most bivalves are sedentary suspension feeders, attached to the substrate by strong threads.

A mollusk with a shell that has two halves is most likely in the class ____________.

Bivalvia

Segmentation

Body may be divided into regions called segments Occurs in annelid worms, arthropods, and chordates Allows specialization of body regions

The change in population size over any time period can be written: ΔNΔt=rN If a starting population size is 300 individuals and there are 10 births and 25 deaths per year, the per capita growth rate (r) is ____ and the new population size after one year will be _____. A. 0.15; 315 B. 15; 315 C. -0.15; 285 D. -0.05; 285

C. -0.15; 285 WRONG

You observe and dissect an animal that looks like a fish. It has a cartilaginous skeleton, no swim bladder, and jaws. This animal is most likely in the phyla ______________.

Chondrichthyes

Subphylum Myriapoda

Class Diplopoda - millipedes •2 pairs of legs per segment, herbivorous Class Chilopoda - centipedes •1 pair of legs per segment, carnivorous Millipedes and centipedes. (a) Millipedes have two pairs of legs per segment. (b) The venom of the giant centipede (Scolopendra heros) is known to produce significant swelling and pain in humans.

dispersion patterns

Clumped Most common Resources tend to be clustered in nature (e.g. limited) Social behavior may promote this pattern Uniform Competition may cause this pattern May also result from social interactions Random Rarest Resources are rarely randomly spaced May occur where resources are common and abundant Three types of dispersion. (a) A clumped distribution pattern, as for these plants clustered around an oasis, often results from the uneven distribution of a resource, in this case, water. (b) A uniform distribution pattern, as for these nesting black-browed albatrosses (Diomedea melanophris) on the Falkland Islands, may be a result of competition or social interactions. (c) A random distribution pattern, as for these bushes at Leirhnjukur Volcano in Iceland, is the least common form of spacing. Species may have uniform, random, or clumped distribution. Territorial birds such as penguins tend to have uniform distribution. Plants such as dandelions with wind-dispersed seeds tend to be randomly distributed. Animals such as elephants that travel in groups exhibit clumped distribution. (credit a: modification of work by Ben Tubby; credit b: modification of work by Rosendahl; credit c: modification of work by Rebecca Wood)

Social Behavior in Insects

Common in bees, wasps, ants, and termites Exhibit division of labor The division of labor in insect societies. Individuals from the same insect colony may appear very different. Among these army ants (Eciton burchelli) from Paraguay, there are (a) workers that forage for the colony, soldiers (with large mandibles) that protect the colony from predators, and (b) the queen, which reproduces and lays eggs.

Subphylum Crustacea

Crabs, lobsters, barnacles and shrimp Marine, fresh water, and terrestrial Unique in having two pairs of antennae Mandibles, maxillae and maxillipeds Walking legs and swimmerets •First pair of walking legs may be modified into claws Carapace may extend over cephalothorax May be predators, scavengers, or filter feeders Nauplius larva very different from adult

Chordates with a backbone

Distinguished by having chordate features as well as: 1.Vertebral column 2.Cranium 3.Endoskeleton of cartilage or bone Additional common features: 1.Multiple clusters of Hox genes -Permitted increasingly complex morphologies 2.Diversity of internal organs Examples of critically endangered vertebrate species include (a) the Siberian tiger (Panthera tigris), (b) the mountain gorilla (Gorilla beringei), and (c) the harpy eagle (Harpia harpyja). (The harpy eagle is considered "near threatened" globally, but critically endangered in much of its former range in Mexico and Central America.) (credit a: modification of work by Dave Pape; credit b: modification of work by Dave Proffer; credit c: modification of work by Haui Ared) Deuterostome phylogeny. All chordates are deuterostomes possessing a notochord at some stage of their life cycle.

ecological footprint

Earth's carrying capacity for the human population depends on lifestyle Ecological footprint - amount of productive land needed to support the average individual Average global size is about 3 hectares (1ha=10,000 m^2) Wide variation is found around the globe 7.5 ha for Canadians, 10 ha for Americans In most developed countries the largest component of productive land is needed for energy If everyone required 10 ha, humans would require three Earths The term ecological footprint refers to the amount of productive land needed to support the average individual of that country.

History of Animal Life

First animals were invertebrates, emerged at the end of the Proterozoic era

types of mortality factors

For a density-dependent factor, mortality increases with population density; for a density-independent factor, mortality remains unchanged. For an inverse density-dependent factor, mortality decreases as a population increases in size.

Diploblastic

Having two germ layers.

Class Cephalopoda

Morphologically complex class of 780 species Fast-swimming marine predators Mouth with beaklike jaw surrounded by arms Octopus Hunter Giant Suckers Nautiluses have retained an external, chambered shell Foot modified into a muscular siphon, used in propulsion Have been shown to be highly intelligent and can learn through observation Closed circulatory system Blood contains hemocyanin Use ink or camouflage as defense Can weigh over 1000 pounds (like colossal squid)

human population growth

In 2011, the world's population was estimated to be increasing at the rate of 145 people a minute 2 in developed nations + 143 in less developed nations This is a huge disparity! Estimated to reach 10 billion around the year 2100 Human population growth was low until beginning of agriculture and animal domestication Between 1750 and 2011, population surged from 800 million to 7.1 billion

gastrulation

In animal development, a series of cell and tissue movements in which the blastula-stage embryo folds inward, producing a three-layered embryo, the gastrula.

The kinetic skull

In snakes and lizards, both the upper and lower jaw are movable, thereby permitting large prey to be swallowed. This Horned bush viper (Atheris ceratophora) is swallowing a leaf folding frog.

Cestode/Tapeworm life cycle

Often requires two different vertebrate species to begin life cycle (ex: cattle or pigs) Another host required to complete development (ex: humans) Scolex attaches to host Proglottids develop thousands of eggs and are continuously shed in feces Humans often infected by eating undercooked infected meat

Mammalian teeth

Mammals have different types of teeth, according to their diet. (a) The wolf has long canine teeth that bite its prey. (b) The deer has a long row of molars that grind plant material. (c) The beaver, a rodent, has long, continually growing incisors used to gnaw wood. (d) The elephant's incisors are modified into tusks. (e) Dolphins and other fishes or plankton feeders have numerous small teeth used to grasp prey.

logistic model fit

Model fits some populations but not others Often provides a good fit for laboratory cultures Variations in nature change resource levels that cause changes in carrying capacity Time lags may cause temporary overshoots Logistic growth of yeast cells in culture. Early tests of the logistic growth curve were validated by growth of yeast cells in laboratory cultures. These populations showed the typical S-shaped growth curve.

The phylum that contains snails, slugs, and squids, is known as _____________.

Mollusca

Mammals are amniotes that have hair and produce milk

Monotremes are egg-laying mammals. Living monotremes include •the duck-billed platypus and •Echidnas (spiny anteaters). •Unlike monotremes, the embryos of marsupials and eutherians are nurtured by a placenta, in which nutrients from the mother's blood diffuse into the embryo's blood.

Subphylum Hexapoda

More insect species than all other animal species combined •Important crop pests, disease vectors, pollinators, and decomposers Six legs Wings crucial to success - outgrowths of body wall 35 orders - differences in wings and mouthparts (mandibles and maxillae) Separate sexes with internal fertilization Metamorphosis -Complete - 4 stages, adult and larval stages very different -Incomplete - 3 stages, young resemble miniature adults

Characteristics of Animals

Multicellular, heterotrophs NO cell walls extensive extracellular matrix which provides support Unique cell junctions hold cells in place and facilitate communication among them, (Anchoring, tight, and gap junctions)

If a different result occurred in the Fiorito and Scotto experiment such that observer octupi chose red and white balls at equal rates, what could be concluded about learning in octupi?

Octupi may learn by direct experience, but not by observation.

The Arthropod Body Plan II

Open circulatory system (blood is pumped into body cavities where tissues are surrounded by blood) Gas exchange occurs via gills or tracheal system with spiracles Complex digestive system with mouth, crop, stomach, intestine, and rectum Excretion - metanephridia or Malpighian tubules

blastopore

Opening formed during embryonic development for the digestive tract/endoderm.

Nematode Examples

Parasitic heartworms infesting a large artery in a porpoise. Horsehair worms in a ghost shrimp and grasshopper. Reproduction usually sexual with separate males and females -Females generally larger than males -Internal fertilization Caenorhabditis elegans - model organism (Crawling ->) Large number of species parasitic in humans and other vertebrates -Ascaris lumbricoides - over 1 billion people infected -Necator americanus - hookworm -Enterobius vermicularis - pinworm -Wuchereria bancrofti - causes elaphantiasis

per capita growth rate

Per capita growth rate, r = (b - d) Why does this make sense? What if we switched b and d? and Differential equation notation, dN / dt the equation ∆N/∆t=bN-dN is rewritten as dN/dt=rN For our rabbit population example,

Age Structure

Relative numbers of individuals in each defined age group Commonly displayed as population pyramid Helps predict future population growth

Age Classes

Reproductive strategy has a strong effect on subsequent age classes of a population Semelparous organisms produce groups of same-aged young, called cohorts uIteroparous organisms have young of different ages Age classes can be characterized by specific categories Years in mammals, stages in insects, size in plants A population increasing in size should have many young and a decreasing population should have few young An imbalance in age classes can have a profound influence on a population's future

Molecular Views of Animal Diversity

Scientists now use molecular techniques to classify animals Compare similarities in DNA, RNA, and amino acid sequences Closely related organisms have fewer differences than those more distantly related

Other Chelicerates

Scorpions •Pedipalps modified into claws •Abdomen tapers into a stinger used to inject venom •Bear live young Mites and ticks •Two main body segments are fused •Many mites are free-living scavengers •Ticks are vertebrate ectoparasites

Your lab group is charged with the identification of an unknown creature. Your lab partners believe that is a small annelid because of its wormlike appearance. You argue it is a nematode. To convince your lab partners, you point out certain distinguishing characteristics. Check the characteristics that are associated with the annelids.

Segmented body plan Secretes hirudin

The Arthropod Body Plan

Segmented with jointed appendages for locomotion, food handling, or reproduction •Tagmata - fused body segments Extensive cephalization •Well developed sensory organs for sight, touch, smell, hearing, and balance •Compound eyes - ommatidia (many lenses) •Some species also have simple eyes (ocelli) Sophisticated brain consists of cerebral ganglia connected to several smaller ventral ganglia

reproductive strategies

Semelparity - produce all offspring in single reproductive event Occurs in salmon, bamboo, and agave, as well as many insects and other invertebrates Individuals reproduce once and then die Iteroparity - repeated reproduction at intervals throughout the life cycle Common in most vertebrates, perennial plants, and trees Seasonal iteroparity - distinct breeding seasons Continuous iteroparity - humans, reproduce repeatedly at any time of the year May be favored in unpredictable environments

Ecdysozoa

Separation from Lophotrochozoa supported by both molecular data and morphology Named for ecdysis - molting A cuticle provides support and protection Some species undergo metamorphosis Internal fertilization •Allows colonization of dry environments Of the eight phyla, nematodes and arthropods are most common

examples of different reproductive strategies

Species such as (a) agave plants (Agave shawii) are semelparous, meaning they breed once in their lifetime and then die. This contrasts with (b) blue tits (Parus caeruleus) and (c) chimpanzees (Pan troglodytes), which are iteroparous and breed more than once in their lifetime.

Genes used in Molecular Systematics

Studies often focus on the gene for small subunit ribosomal RNA (SSU rRNA) Universal in all organisms Changes slowly over time Hox genes also often studied Found in all animals Duplications in these genes may have led to evolution of complex body forms Phylogenies constructed using SSU rRNA and Hox genes are similar and often agree with those based on morphology

Elephantiasis

The disease is caused by the nematode parasite Wuchereria bancrofti, which lives in the lymphatic system and blocks the flow of lymph.

Pace of the Demographic Transition

Varies between countries depending on culture, economics, politics, and religion The demographic transitions in Sweden and Mexico. Although the demographic transition began earlier in Sweden than it did in Mexico, the transition was more rapid in Mexico, and the overall rate of population increase remains higher. (The spike in the death rate in Mexico prior to 1920 is attributed to the turbulence surrounding the Mexican Revolution.)

veliger snail

Veligers are free-swimming larval forms of mollusks that look more like adults than the trocophore larvae from which they develop

Exponential Growth

When r > 0, population increase is rapid Characteristic J-shaped curve Exponential or geometric growth Intrinsic rate of increase, r_max = r at maximum Because population growth depends on the value of N as well as the value of r, the population increase is even greater as time passes May occur initially under some conditions Reintroduction of a population to a habitat, growth of introduced exotic species, and global human population

The logistic growth model predicts that the growth rate of a population will decrease as the population size approaches the environment's carrying capacity (K). Under what circumstances would you predict that a population would increase in size as it goes over and above its carrying capacity?

When resources are declining more rapidly than reproduction is declining.

dueterostome

blastopore becomes anus

protostome

blastopore becomes mouth

The circulatory system found in annelids is usually

closed

Choanoflagellates

closest living relatives of animals protists that have a single flagellum surrounded by a collar of cytoplasmic tentacles

coelomate

coelom completely lined with mesoderm , earthworms(annelids), humans(mammalia)

Pseudocoelomate

coelom only partially lined with mesoderm rotifers, roundworms (nematodes)

ctenophore

comb jellies

Phylum Ctenophora

comb jellies eight rows of cilia on surface beat for propulsion two long tentacles without stinging cells colloblasts secrete sticky substance first complete gut - mouth and two anal pores hermaphoroditic biolumiescent

Lophotrochozoa

either a lophophore or trochophore larva

lophotrochozoa

either have a lophophore (crown of ciliated tentacles, bryozoans, brachiopods) or a trochophore (mollusks, annelids) rotifers that have lophophore (feeding device) plthyelminthes which have trocophore like larvae

Wuchereria bancrofti is the name of a nematode that primarily causes _____________.

elaphantiasis

hox genes

encode for proteins that allow proper positioning of body parts along an axis

Population

group of interbreeding individuals occupying the same habitat at the same time uex: Water lilies in a particular lake uex: Humans in New York City

r 1

growth rate

r-selected species

high rate of per capita population growth (r), but poor competitive ability Grow quickly and reach reproductive age early Examples: Insects, weeds, frogs (type 3)

acoelomate

lack a body cavity and instead have mesenchyme Flatworms (Platyhelminthes)

After an ocean fishing trip, you return with a species that you have not encountered before. Your curiosity will not allow you to dismiss your catch without proper identification. Your fishing buddy argues that this is just another species of bony fish. Upon dissection, you conclude that it belongs with a taxonomic grouping that includes the sharks. What observed feature of your catch would lead you to such a conclusion?

large oil filled liver

Germ layers

mesoderm (middle layer) ectoderm (outer layer) endoderm (inner later)

Ecodysozoa

nematodes - roundworms arthropods - insets and aracnects

The phylum that contains snails, slugs, and squids, is known as _____________.

mollusca

Ecdysis

molting

Animal Classification

monophlyetic

A mammal that can lay eggs would be considered a ______________.

monotreme

The Trematode/Fluke Life Cycle SLIDE 36

more complex than cestode first(intermediate) host is usually a mollusk final (definitive) host is usually a mollusk May include second or even a third intermediate host Blood flukes cause schistosomiasis •Infect over 200 million people, mostly in tropics •Causes chronic inflammation and blockage of organs, and can be fatal Infection rates reduced with clean water

K-selected species

more or less stable populations adapted to exist at or near carrying capacity, K Devote energy to growth and maintenance Examples: Humans, elephants, trees Vulnerable in a human-dominated world (type 1) An easy way to remember the two is to keep in mind what the species is selecting for.

cnidocytes

nemoatocysts - defense, cnidocil (hair like trigger) simple nerves and contractile fibers to sting

Mesoderm derives into

muscles and internal organs.

A population would be most likely to likely have a low growth rate under what condition?

near carrying capacity

Indicate the pattern of dispersion that is being described: Seedlings of a wind-dispersed plant on a fertile forest floor.

random

phylum cnidaria

sessile polyp - tubular body with tentacles surrounding opening , aboral end attached to substrate, may be single (sea anemones) or colonial (corals) , corals deposit limestone which produces reefs Motile medusa - umbrella -shaped body with a mouth on the underside surrounded by tentacles, like a jellyfish, have sensory organs near bell margin statocysts for equilibrium ocelli are photosensitive , no eyes but can sense when light is around

sponge reproduction

sexual- hermaphrodites (produces egg and sperm) asexual- small fragment or bud may detach and form a new sponge

Ectoderm derives into

skin and nerves

Tripoblastic

three germ layers

flatworm anatomy

triploblastic - have all 3 tissue layers mesoderm innovation allows complex organisms acoelomate - lacking fluid-filled cavity

Animals displaying bilateral symmetry can be divided into no more than one vertical plane at midline, where each half creates a mirror image of the other. True or False?

true

Animals with radial symmetry include the phyla Cnidaria and Ctenophora.

true

Life history strategies differ along a continuum from what is referred to as "r-selected species" to "K-selected species". Species that have a high number of offspring produced at one time are considered r-selected species. True or False?

true

One advantage of segmentation is that iIf the organs in one segment fail, the organs of another segment will still function. True or False?

true

Indicate the idealized survivorship curve being described: A frog species that lays a massive amount of eggs, with many that will not survive to sexual maturity.

type 3

logistic vs exponential

uPopulation growth slows as it approaches K Exponential (J-shaped) growth occurs in an environment with unlimited resources, whereas logistic (S-shaped) growth occurs in an environment with limited resources.

Indicate the pattern of dispersion that is being described: A mature stand of pine trees competing for water and space.

uniform

Indicate the pattern of dispersion that is being described: A species of lizards in which males defend territories of roughly the same size.

uniformed

sponge structure

water is drawn through pores into spongocoel(central cavity) and flows out through osculum top choanocytes line spongocoel trap and eat small particles and plankton mesohyl between chaonocytes and epithelial cells Amoebocytes absorb food from choanocytes, digest it, and carry nutrients to other cells Spicules (skeletal fibers) or spongin for support Some species produce defensive chemicals

Cyclostomata Lampreys

•Have a notochord and rudimentary vertebral column •Marine lampreys are parasitic as adults •Freshwater species usually mate and die without feeding •All species spawn in freshwater streams •Lamprey adults are parasites that penetrate the sides of fishes with their rasping tongues. •Larval lampreys •resemble lancelets and •are suspension feeders that live in freshwater streams, where they feed, buried in sediment. These parasitic sea lampreys attach to their lake trout host by suction and use their rough tongues to rasp away flesh in order to feed on the trout's blood.

Family Hominidae

•Humans related to chimpanzees and other apes but did not evolve directly from them •All hominoids shared a common ancestor -Subfamily Ponginae - orangutans -Subfamily Homininae •Tribe Gorillini - gorillas •Tribe Panini - chimpanzees Tribe Hominini- humans and their ancestors

Actinopterygii: the Ray-Finned Fish

•Includes all bony fish except coelocanths and lungfish •Fins supported by thin, bony, flexible rays •a buoyant swim bladder (derived from an ancestral lung).

Osteichthyans

•Includes all vertebrates with a bony skeleton •Bony fishes are most numerous of all fishes -Two living clades •Actinopterygii - ray-finned fishes •Sarcopterygii - lobe-finned fishes •Bony skeleton and scale-covered skin •Operculum covers gills •Swim bladder for buoyancy •Most species reproduce via external fertilization know the nostrils, gills, operculum, dorsal and caudal fin

Sarcopterygii: the Lobe-Finned Fish

•Includes tetrapods •Fins supported by skeletal extensions of the pectoral and pelvic areas and moved by muscles •Lobed fins •Actinistia - coelacanths -Believed extinct until 1938 -Special joint in skull gives powerful bite -Swim bladder filled with oil rather than gas •Dipnoi - lungfish -Live in oxygen-poor freshwater -Both gills and lungs - can drown if unable to breathe air -Muscular lobe fins allow them to traverse land (Video)

Cyclostomata

•Jawless eel-like animals •Hagfish •Lack eyes, jaws, fins, and vertebrae •Skeleton comprised of notochord and cartilaginous skull •Essentially blind with a keen sense of smell •Produce copious amounts of slime (anti predator defense) •REMEMBER: They have a head , but no jaws or vertebrae.

New fossil discoveries are filling in the gaps of tetrapod evolution

•Like plants, vertebrates faced obstacles on land in regard to •gas exchange, •water desiccation, •structural support, and •reproduction. •Animal obstacles also included •finding a means of locomotion and •adapting sensory organs that worked well in water but not on land.

Distinguishing characteristics of mammals

•Mammary glands secrete milk •All mammals have hair (more or less) •Only vertebrates with specialized teeth •Enlarged skull •Brain enlarged in large skull •Single lower jaw bone •3 inner ear bones External ears

Phylum Echinodermata

•Modified radial symmetry (five parts) in adults (pentasymmetry) •Cephalization absent, simple nervous system •Endoskeleton covered with spines and pedicellariae •Water vascular system with tube feet functions in movement, gas exchange and feeding •No excretory organs - respiration and excretion by diffusion •Autotomy - Can intentionally detach body parts (or lose them) that later can regenerate •Reproduce sexually with separate sexes and external fertilization Echinoderms. (a) Sea star. (b) Brittle star. (c) Sea urchin. (d) Sea lily. (e) Sea cucumber.

Phylum Arthropoda

•Named after their jointed appendages •Perhaps most successful phylum •75% of all described living species •Success related to body plan that permits them to live in all major biomes •Exoskeleton made of chitin and protein •Can be extremely tough or soft and flexible •Provides protection, point of muscle attachment •Relatively impermeable to water •There are over a million species of arthropods (phylum Arthropoda), including crayfish, lobsters, crabs, barnacles, spiders, ticks, and insects. •The diversity and success of arthropods are due to their •segmentation, •hard exoskeleton, and •jointed appendages, for which the phylum is named.

Phylum Rotifera

•Named for ciliated crown (corona) •2000 species - mostly freshwater and microscopic •Digestive tract with mouth and anus -Feed on plankton and decomposing organic matter •Mouth opens into a muscular pharynx called a mastax •Jointed foot with pedal glands •Pseudocoelomate reproduce through Parthenogenesis -unfertilized diploid eggs develop into females

Amphibian diversity

•Order Anura - frog and toads -Nearly 90% of amphibians -Carnivorous adults, herbivorous tadpoles •Order Apoda - caecilians -Nearly blind tropical burrowers -Secondarily legless -Uterine milk nourishes young inside mother's body •Order Urodela - salamanders -Often have colorful skin patterns Paedomorphosis - adult has larval characteristics a) Most amphibians are frogs and toads of the order Anura, including this red-eyed tree frog (Agalychnis callidryas). (b) The order Apoda includes wormlike caecilians such as this species from Ecuador, Siphonops annulatus. (c) The order Urodela includes species such as this mud salamander (Pseudotriton montanus).

Phylum Mollusca

•Over 100,000 species •Great diversity •Snails, clams, octopuses, chitons •Mostly marine •Economic, aesthetic, and ecological importance •Food •Farming oysters for pearls •Damage to plants and wooden structures •Intermediate hosts of parasites (like trematodes/flukes) •Exotic species can be serious pests •E.g. Zebra mussels Found in the Great Lakes

Primates

•Primarily tree-dwelling species (arboreal) •Evolved about 85 mya •Defining characteristics -Grasping hands with opposable thumbs -Large brain -Some digits with flat nails (not claws) -Binocular vision -Complex social behavior and well-developed parental care

Chondrichthyes

•Sharks, skates, and rays •Cartilaginous fish -Skeleton of flexible cartilage -Derived character within the Chondrichthyes (not ancestral) -Developmental change prevented ossification of cartilage •Denser than water •Sharks maintain buoyancy using fins and large oil-filled liver Skates and rays have a flattened body •Oxygen is extracted from water using gills •Dual-chambered heart - single circulation •Sharks among earliest fish to develop teeth -Teeth not set into jaw •Powerful sense of smell •Lateral line system- pressure wave detection

amphibians

•Successfully invaded land but reproduce in water •Lungs are an adaptation to a semiterrestrial lifestyle •Buccal pumping forces air into lungs •Skin can also absorb oxygen •3-chambered heart •often have poison glands in their skins •External fertilization •Larval stages aquatic •Moist skin Undergo metamorphosis a) Amphibian eggs are laid in gelatinous masses in water. (b) The eggs develop into tadpoles, aquatic herbivores with a fishlike tail that breathe through gills. (c) During metamorphosis, the tadpole loses its gills and tail and develops limbs and lungs

Insects are the Most Successful Group of Animals

•The extraordinary success of insects is due to: •body segmentation, •an exoskeleton, •jointed appendages, •flight, •Different mouthpart adaptations, •a waterproof cuticle, and •a complex life cycle with short generations and large numbers of offspring.

transitional taxa

•Tiktaalik rosae, or the Fishapod •Broad skulls with eyes on top, lungs, pectoral fins with 5 finger-like bones •Species increasingly lived on land but still tied to water for reproduction

Reptiles

•Traditional classification has three living amniotes - reptiles, birds and mammals •Rough, scaly skin •Reptiles like lizards, turtles, alligators, crocodiles, and snakes are ectothermic -Birds are now considered part of reptilian lineage (endothermic) (high metabolism) -Five extinct clades -Ornithischian and saurischian dinosaurs -Flying reptiles (pterosaurs) Ancient aquatic reptiles (icthyosaurs and plesiosau

Tetrapods: Gnathostomeswith Four Limbs

•Transition to land involved adaptations for locomotion, reproduction, and to prevent desiccation •Sturdy lobe-finned fishes became animals with four limbs •Vertebral column strengthened, hip and shoulder bones braced against backbone •Relatively simple changes in gene expression, especially Hox genes

Transitional forms

•Wings and feathers may have enabled gliding, helped keep the animal warm, or cut down glare when hunting Transitional forms between dinosaurs and birds. (A) Archaeopteryx lithographica was a Jurassic animal with dinosaur-like features as well as wings and feathers. (B) Caudipteryx zoui was a dinosaur with feathers on its tail and wings. (C) Confuciusornis sanctus was a birdlike animal with a horny, toothless beak.

Eutherians

•bear fully developed live young and •are commonly called placental mammals because their placentas are more complex than those of marsupials. •Examples of eutherians include: •Elephants •Dogs •Whales Humans