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124 Cards in this Set

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Behavior can be explained at how many levels, by who, and what are they?
4 levels of Tinbergen:
1) Proximate cause
2) Development
3) Evolutionary cause
4) Phylogenetic origin
Behavior is an evolved character. :-p
Explain proximate cause and what it's part of.
underlying hormonal , neuronal , and cognitive mechanisms that give rise to behavior. "tingergen's four"
mechanistic-how
the two categories of proximate cause are...
1) fixed action pattern-innate and stereotyped behavior, triggered by a simple stimulus called a releaser.
2) supernormal stimulus-stimulus that induces a response more effectively than the naturally occuring sign stimulus.
1)yawning, goose, babies
2)seagulls pecking on red spot on beak as opposed to 3 red stripes on pencil.
Explain Developmental cause and what it's part of.
The way in which a particular behavior emerges or is acquired during the lifetime of an individual. nature or nurture? "tinbergen's four"
how did the mechanism come to be, learnign etc (during a lifetime)
The 4 categories of developmental cause are..?
1)genetically encoded,"hardwired"
2)learned by trial and error
3)copied from other individuals
4)actively taught by others
1) moth-falling from bat
2)owls and hunting for prey
3)bird and milk bottles
4)crows
Explain Ultimate (evolutionary) cause and what it's part of.
just like physical characters, behaviors evolve. why were they selected? how they help the organisms "fit" its environment?--selective or adaptive "purpose"; reason that a particular behavior has evolved. "tinbergen's four"
why?
The behavioral adaptations within ultimate cause help to deal with what and what are some classic problems?
the abiotic world, other species, conspecifics. classic problems are: mate choice, optimal foraging behavior, scanning for predators, parental care.
Explain Phylogenetic Origin and what it's part of.
we can put behavior characters on a phylogenetic-tree, which can help us understand when different traits evolved over the evolutionary history of a species or set of species.---an explanation in terms of evolutionary history; that place in a phylogenetic lineage where a behavioral trait arose.
what does natural selection favor?
individuals that help themselves leave as many surviving offspring as possible.




what is altruistic behavior and what are some common examples?
actions that help other individuals at a cost to the actor. ex: helping at the nest, foodsharing, social insects, coalition formation, alarm calls
What of group selection? what is a problem involved?
favors traits or behaviors that evolve "for the good of the species/group". the animals show altruistic restraint: in fights, reproductive rate, resource use. problem: what happens to a gene for selfish behavior? the frequency of the allele increases.it just doesnt work if you think about the "prisoner's dilemna game".
Kin Selection is one explanation for group selection. why do parents care for their offspring?
natural selection favors it, genes get passed on, etc.
offpring: 1/2 of parent's genes
full sib: 1/2 of sib's genes

should sibs help sibs just as parents help offspring? how is this explained?
Coefficient of relatedness r -the probability that two individuals share a gene due to common decent (multiply fraction r by itself the number of times there are generations b/w)
principle of segregation: The separation of paired alleles or homologous chromosomes, especially during meiosis, so that the members of each pair appear in different gametes.
Explain Hamilton's rule.
A gene for altruistic behavior will increase in frequency in a population when : c<br. c=cost to actor, b=benefit to recipient, r=coefficient of relatedness
"i'll gladly lay down my life for two brothers or 8 cousins" -jbs haldane
Explain Reciprocal altruism.
provide help now so as to be the recipient of help later--involves unrelated individuals like bats sharing food or predator inspection among guppies. why not cooporate?gets around the "prisoner's dilemna game" which models altruism.
"like love among lawyers"
"tit for tat" -doing whatever the other participant did in the last round.
What are viruses?
small infectious particals that contain the genetic instructions for their own replication.
Ex: HIV, influenza, smallpox, measles, herpes, most colds...
The basic virus design consists of..?
some have a phospholipid bilayer envelope and glyco proteins, protein capsid capsomere, genetic material (RNA or DNA)
How do viruses replicate?
Using the hosts' cellular machinary: all borrow the host's translational machinery (ribosomes, etc), typically dont code for protein target, signalling, or assembly-uses host's pathway, borrow ATP, the energy sources, nucleotide bases and amino acids, sometimes host DNA polymerase, and some RNA viruses have RNA replicase, reverse transcriptase.
What is the basic life-cycle of a virus? explain the lytic cycle (budding or bursting), dont worry about the lysogenic cycle.
1)enter host cell, by trick fusing, injection
2)replicate genetic material and transcribe to produce mRNAs
3)viral mRNAs are translated and proteins processed.
4)particles assemble inside host, and then burst (lysis) or bud to exterior.
Are viruses alive? what are the 4 factors that may dispute that?
1) Genetic material (DNA or RNA)-they have to have the the same genetic code as the host b/c they need the host to do the reading.
2) Evolve by natural selection-high mutation rate (esp in RNA based ones), great variation, differential survival by trait, theyre heritable.
3) No autonomous replication or translation
4) No homeostasis or independent metabolism.
theyre the most common nucleic acid-based on the planet.
homeostasis=The ability or tendency of an organism or cell to maintain internal equilibrium by adjusting its physiological processes.
In regards to where viruses came from, what is the 'organisms down, RNA right, Genes up' concept?
Organisms down-used to be more complex, intracellular bacteria, then were able to lose machinery and take advantage of those of host
RNA Right--suspected that original forms were not DNA but RNA forms, thus making viruses relics of the RNA world.
Genes Up--"selfish genetic" particles that code for horizontaly genetic elements, ends up separating from host "purpose" and even being able to move laterally b/w hosts.
What are the types of viruses?
1)no membrane vs membrane
2)single vs double-stranded
3)RNA(rabies, influenza, measles, HIV) vs DNA(smallpox, herpes)
4)"Ordinary"(most)vs retroviruses(HIV)
Describe the type of virus called a retrovirus.
they have RNA genome and are used as templates to synthesize DNA via the reverse transcriptase enzyme. The DNA is then inserted into the host genome.
True or false: 1)bacteria and archaea have more diverse metabolic capabilities than eukaryotes, prob archaea more than all.
2)are primarily single-celled microbial organisms
true, true
define the difference b/w "commensal," "mutualism" and "symbiotic"
commensal-neutral effect on host
symbiotic-more essential(ex:termites, cyanobacteria (blue-green algae) that do N2 fixation and photosynthesis), can be commensal, parasitic, or mutualistic
mutualistic--benefit to both host and "invader"
Define some differences b/w bacteria and archaea.
Neither have nuclei or oraganelles.
They have different cell membranes.
Archaea are all unicellular, cell walls of polysaccharides, unique plasma membranes but ribosomes and RNA polymerase similar to eukaryotes.
Bacteria-cell walls made of peptidoglycan, distinct forms of ribosomes and RNA polymerase.They are animal-associated (ECF or ICF), soil-living, and aquatic (esp cyanobacteria).
Bacteria and Archaea were grouped together as prokaryotes based on..?
morphology
What are the 3 types of gene transfer in bacteria?
1)Transduction: bacterial genes picked up "by accident" by a bacteriophage and inserted into another bacterium.
2)Transformation: loose DNA picked up from the environment and incorporated into the environment.
3)Conjugation: exchange or plasmids-circular molecules of semiautonomous DNA (often carrying resistance genes).
Those of the domain Archaea deal with extreme environments, what types are there?
1)Extreme thermophiles-heat
2)Extreme halophiles-salinity
3)Psychrophiles-ice
"Eukaryote" means...?and they are defined by what?
"true-kernel" and are defined by the nuclear envelope.
What are protists?
all eukaryotes except plants, animals, fungi
they live just about everywhere
true or false: protists were originally unicellular
true. multicellular-wise, ex are red, brown, green algae that evolved 3 times independently in protists.
what is a technique for discovering microscopic organisms that cannot be grown in the lab?
Direct sequencing-purify DNA directly from an environmental sample
Genomic sequencing involves..
looking at all of the genomes in a habitat
ways of getting nutrients are in protists...?
1)Absorptive lifestyles--like many bacteria and archaea except all use glucose or other sugars, take in food molecules directly from environment
2)Photosynthesis--using kinetic energy in light (ATP is cash, stores chemical energy). diversity in pigments and wavelengths harvested perhaps exist in order to avoid competition (n.selection).
3) Ingestive feeding--dont have cell wall obviously, engulf pockets of food-packman-evolution of predation by engulfing cells.
What does sex in protists involve?
meiosis and fusion of haploid gametes to form a diploid zygote and variation in life cycles=the sequence of events in the life of an individual.
What is 'alternation of generations'?
the presence of mulicellular diploid and haploid individuals within the life cycle.
Sporophyte=?
a multicellular, diploid individual that produces haploid spores by meiosis; these spores germinate and divide by mitosis to form a haploid gametophyte.
Gametophyte=?
a haploid, multicellular ind. that produces gametes by mitosis; thse gametes fuse (fertilization)to form a diploid cell(zygote) that develops into a sporophyte.
Spore=?
a single cell (n)produced by mitosis or meiosis that is capable of developing into an adult organism (w/o fusing with another cell). -dispersal stage.
Describe the functions of the two membrane-bound organelles, mitochondria and chloroplasts.
Mitochondria=produce ATP that store chemical energy and even though they may be vestigial, all eukaryotes have them. site of aerobic respiration.
Chloroplasts=photovolaic, form ATP and sugars, in plants, contain chlorophyll where photosynthesis occurs, amino-acids, purine, etc.
What is the endosymbiotic theory of origin with eukaryotes?
evidence that eukaryotes were not originally photosynthetic or having chloroplasts. "eukaryotes engulfed bacteria"
1) size of mitochondria and chloroplasts smaller , about size of bacteria
2)number of membranes; 2
3)genes in them highly variable in number but not in function. some have chloroplasts (bacteria do) depending on the bacteria.
4)chrosome structure is circular, w/supercoiled DNA
5)replication of mitochondria and chloroplasts , split in two w/ copy
6)phylogeny of mitochon and chlorop genes closest relative-bacteria.
where do plants occur on the tree of life?
after Chara, transition to land took place, first listed as liverworts, hornworts, mosses etc.
are land plants derived from green algae or green algae from land plants?
the former-chara is a green algae.
Organisms have 2 fundamental nutritional needs: ?
1)acquiring chemical energy in form of ATP
2)obtaining carbon in form used to synthesize molecules needed to build cells.
Organisms produce ATP in 3 ways and one separate way which are:?
1)Phototrophs: light-feeders-use light energy to promote electrons to tope of e- transport chain
2)Organotrophs:oxidize organic molecules w/ high potential energy, cellular respiration->ATP
3)Lithotrophs: "rock-feeders"-inorganic molecules, like NH3 or CH4, cellular respiration->ATP
4)fermentation: ATP made by glycolysis
Organisms get carbon by :?
1)processing CO2 and CH4, are autotrophs (self-feeders)
2)heterotrophs (other-feeders)
Chara lived in areas of..
fresh water and edges of ponds
Green Plants include..
all green algae and land plants
example of reversion in land plants?
lilies are "land plants" (angiosperms) but live in water (a separate ex is that of the whale)
What types of habitats are occupied by liverworts and mosses? by gymnosperms?
1)wet
2)wet to dry
A central idea is that of adaptations to land, wet to dry transition. what are the 5 main points?
1)Resistance to drying
2)Transporting water and nutrients
3)Gametangia
4)Pollen
5)Seeds
series of key innovations
What are the innovations involved in Resistance to Drying and any downsides?
1)Cuticle-waxy covering to retain water. wet habitat specimens would have thinner cuticle. the downside is that it doesnt let gases pass through, esp thick ones.
2)Pores and Stomata-a)openings in cuticle, gets CO2 in . downside, lets moisture out. b)structure that allows gas exchange but controls/reduces water loss (guard cells)on underside of leaf.
What are the innovations involved in Transporting Water and Nutrients?(vascular tissue). Why are they important? How does morphology of non-vascular plants compare to morphology of vascular plants?
Types of water-conducting cells: 1. tracheids as first (in fossil record). they have long pipes, cell-wall [wich are dead at maturity]. Primary cell wall(mostly cellulose), then secondary cell wall is of lignin and cellulose. The pits are the places w/o secondary cell wall where liquids can pass and travel through tracheids.
2. vessels-later in fossil record. angiosperms.

Imporant b/c: 1. replace evaporative water loss-transpiration (above ground).
2. structural support-lignified secondary cell walls=> make wood. vascular tissues=>stiffened cell walls w/ support of cellulose=>erect growth.
3. vascular plants dont have to dessicate/go dormant.

non-vascular plants are generally shorter.
tissue=groups of cells organized to perform a specific function.
What are the innovations involved in Gametangia?[early groups-lost in later ones, reproduction]
1. enclose gamete-producing tissue in protected structures, formed by gametophyte.
2. Sperm to egg-embryo develops inside structure (is retained). embryo is sporophyte. nutrients are from parent plant.
some closely-related algae have gamentangia.
What is pollen, the innovations involved in it, and the adaptive significance of it?
1. Pollen=a MULTICELLULAR (often 2-3 cells) structure that includes a male gametophyte or is the male gametophyte.
2. encased in a tough coat produced by the sporophyte->sporopollenin. transported by wind, insects, cool b/c they dont need water.
3. In mosses, horsetails, ferns, etc..sperm are "naked" , swimming to egg from male gametangium, they have a dependence on water or rain, and in transit, sperm are exposed to drying.
What is a seed, the innovations involved in it, and the adaptive significances?
1. Seed= another reproductive dispersal structure. embryo (sporophyte)+ food supply (oil, fat, carbohydrates)surrounded by tough case=>dispersal.
2. advantages: protection/nourishment, avoid competition w/ parent gametophyte.
disadvantages: competition, share same resources, offspring can end up "in a bad place".
where did the embryophyte condition evolve?
embryophyte maintained on parent plant. -all land plants (past chara).
In the correlations made b/w flower structure and pollinator, what hypothesis are we invoking?
1. Natural selection has favored the evolution of flowers that are efficient at attracting pollinators. There is heritable variation in traits and so experience differential success.
2. Selection on flower morphology is strong b/c of close relationship b/w reproductive success (RS) and flower traits.
Are fungi monophyletic or paraphyletic?
monophyletic
True or False:the adaptive significance of large long-lived gametophytes to small short-lived is known.
false
what are the growth forms of fungi? elaborate.
1) Yeasts: thy are a taxonomic group but also is a general term for a growth form that's unicellular.
2)Mycelia=multicellular bodies made up of tube-like hyphae. They are constantly growing and move over time, driven by nutrient availability. In many species the cells are haploid at least at some stages of the cycle. At other stages they are dikaryotic (n+n). Some are coenocytic (no cell walls or membrane).
What are the fungi categorized into according to reproductive structure?
1) Chytridiomycota: swimming gametes, aquatic habitats.
2)Zygomycota: haploid, multinucleate hyphae that merge to form a diploid, which then undergo meiosis. these zygospores disperse.
3) Basidiomycota: dikaryotic fruiting bodies like mushrooms, brackets, puffballs--see haploid spores (products of meiosis) produced in basidia.
4)Ascomycota; dikaryotic fruiting bodies in cup fungi, morels, most lichens--see haploid spores (products of meiosis) produced in sac-like structure, the ascus.
Why do gonads of fungi appear aboveground?
for dispersal of spores.
How do fungi make a living (get nutrients)?
they have an absorptive lifestyle: almost all fungi absorb nutrients directly form their environment. the different positions are : 1)saprophyte-decomposes dead plants 2)parasites-feeds on live organisms 3) mutualists (these are also saprophytes)-two species interacting and both benefit.
All fungi are unicellular or consist of ...?
thin, highly branched tubes
what is a problem with the increasing size of a sphere?
volume increases much faster than surface area.
what is key to the efficency of absorption in the mycelia of fungi?
single cells and thin, highly branched tubes have high surface area to volume ratio.
what other types of shapes increase area and decrease volume in structures responsible for absorption?
flattened or folded plates, tube-like structures.
think intestines and lungs
On EC digestion, how do fungi get nutrients in the first place-b4 absorbing them?
they secrete enzymes into food sources. ex: 1)cellulase is an enzyme that breaks cellulose down to glucose. 7 different types are needed.
2)lignin is the hardening substance in the secondary cell wall(wood), broken down by enzyme lignin peroxidase.
1)only a handful of organisms can digest it.
2)only basidiomycetes have this. it only evolved once.
What are the two major ecological impacts of fungi? elaborate.
1)they rot wood.
2)they feed plants.--Mycorrhizae are fungi that live in association with plant roots. a)Ectomycorrhizal fungi (EMF) cover the plant roots, most of them are basidiomycetes. they are extremely common in northern environments and primarly transfer Nitrogen to trees in return for sugars from the plants' photosynthesis.
b) Arbuscular mycorrhizal fungi (AMF) grow and penetrate into plant cell walls (of roots). they are primarily zygomycetes and interact with 80% of land plants. they exist especially in the tropics and wet grasslands and transfer phosphorous to host in exchange for sugars.
where are animals on the tree of life?
close to fungi, choanoflagellates (colonial organisms, sessile, filter feeders).
animals are a monophyletic group distinguished by
1) multicellularity: some of the cells have specialized functions.
2)directed movement: most move at some stage in life cylcle. muscle cells and tissue are unique to animals.
3)ingestive feeding: most animals "eat to live", take in packets of food.
there are approx how many groups in the phylogeny of animals?
35-36
segmentation evolved _____ in protostomes and deuterostomes and include which groups?
1) independently
2)annelids, arthropods, chordates
do sponges have a coelom?
no.
which type of animals are included in the cnidaria, ctenophora, flatworms, molluscs, annelids, nematodes, arthropods, echinoderms, and chordates?
1)those that have stinging cells-anemonies, jellyfish
2)comb jellies
3)flatworms
4)squid, oysters, clams, slugs
5)segmented worms
6)roundworms
7)insects, lobster, crabs
8)sea cucumbers, urchins, sea stars
9)defined by presence of skull, includes vertebrates.
radial symmetry occured where?
cut-off leading up to cnidaria and ctenophera and in adults exists in echinoderms.
multicellularity occured where?
before sponges.
ectoderm and endoderm (2tissues) occured where?
after sponges.
the mesoderm (3tissues, triploblasty) occured where?
after cnidaria and ctenophera
bilateral symmetry occured where?
after cnidaria and ctenophera
the coelom occured where (at least vestigial)?
after cnidaria and ctenophera
according to the molecular tree (in morpho, evolved between nematods and arthropods which are on the main tree. also, the arthropods, annelids and mollusks are grouped together)
protostomes involve what and occured where?
mouth then anus, leading up to the groups of flatworms, molluscs, annelids, nematodes, arthropods.
deuterostomes involve what and occured where?
anus then mouth, before echinoderms and chordates.
what is a pseudocoelom and how well does it operate compared to the coelom?
it has an inner mesoderm as well as an outer one and operates just as well.
describe the sponge.
they have many specialized cells but no tissues according to how far current research goes and are sessile as adults (larvae mobile).
what is a tissue?
a group of cells that are specialized for a particular function.
What are the four key characteristics of animals? elements of the body plan are basic, then variation in mouth parts (feeding) and limbs(movement) exist.
1)Embryonic tissues-consist of triploblasty, Ectoderm:skin, nerves. Mesoderm: internal organs, muscle. Endoderm: gut lining.
2) Symmetry vs asymmetry and radial vs bilateral. jellyfish, combjellies, some sponges have radial symmetry. Bilateral symmetry is associated with "cephalization," formation of a distinct head and tail, -a facing in of environment in one direction. head serves for sensory and ingestion. tail for powered movement.
3)Presence of a body cavity--Coelom is a fluid-filled cavity lined with mesoderm. Mesoderm gives rise to muscles and other tissus. importance of these is a hydrostatic skeleton-->first skeleton in animals!!!!. it is an evolutionary innovation, unique to animal. ex in human body is the tongue.
4)Protostome (mouth then anus) vs deuterostome patterns of development--zygote->cleavage forms ball of cells by mitotic division(no cell growth)->cell movements form invagination in ball by gastrulation(cells of embryo move from outside to inside forming the 3 tissues)->tissue layers (ectoderm, endoderm, mesoderm).
different than how they are DISTINGUISHED exactly.
It is not know whether the protostome or deuterostome pattern is...?
most ancestoral, or anything that's particularly significant between them.
metamorphisis means
"between forms"
The fossil record consists of which major faunas and is consistent with what?
Doushantuo(microscopic fossils, including evidence of sponges, different cell types, multicellular embryos)->Edicardian(sponges, jellyfish, comb jellies, other filter-feeding shallow-water marine animals)->Burgess Shale(soft-bodied animals)....with morphologically described development (sponges->diplogblasts->bilaterally symmetric triploblasts).
Gene Coding shows what and supports what?
supports morphophylogeny for the most part. it consists of the evidence that the most ancient organisms lacked a coelom, protostome development split (ecdysozoa and lophotrochozoa), derived and "developed" conditions existed. ex: coelom.
psuedo coelom comes before or after coelom according to the morphological tree, after what, and occurs in what?
before coelom and after the flatworm. occurs in nematods and rotifiers
what supports that flatworms are acoelomates?
they dont have a coelom but are lophotrochozoans so the coelom must a derived trait in this species.
according to the molecular tree, when did the psuedocoeloms arise and in what groups?
twice during the course of evolution , bodies with psuedocoeloms arose from ancestors that had "true" coeloms, nematodes and rotifers.
Animals need what to exert a force against what to ..?
muscles-cells-tissue, one of 3types of skeletons, move.
what are the 3 types of animal skeletons?
1)hydrostatic-fluid-filled compartment surrounded by bands of muscle.
2)Exoskeleton-hard outer parts that provide attachment sites for muscles.
3)endoskeleton-hard inner parts that provide attachment sites for muscles.
What are the two sources of food for animals?
1)Dead organisms: scavengers (detritus-small organic debri partially decomposed)
2)Living organisms: Herbivory, carnivores, fungivores (parasitism).
Distinguish Parasitism and predation.
Parasitism: harms/kills relatively slowly, usually smaller than host.
Predation: kills rapidly, usually same size or bigger unless they hunt in packs.
What are the strategies of Parasitism?
1)Ectoparasites: outside. parasite/host fitness=+/-, eg., ticks, lice, mosquitoes.
2)Endoparasites: inside. absorb nutrition-tapeworms, hooked worms.
What is a strategy of predators?
heart size increases with need to expend more energy. (dawgs and cats)
What is deposit feeding and what is their anatomic strategy?
they eat their way through a substrate, with bodies more tube-like and streamlined so that the body can easily follow the mouth.
What is suspension feeding?
filter-feeding, they capture suspended material or whole prey in net/filtration structure.
What is the general morphology of the protostome?
they are bilaterally symmetric, troploblastic, many have reduced coelomites, flatworms have none. there are 20 phyla (major monophyletic groups) , most have wormlike bodies.
What are the two major groups of the protostome?
1)Arthropods: crustaceans, insects, arachnids (spider and mites). they have exoskeleton made of chitin (+caco3 in crustacean), segmented body, jointed limbs (vs sac-like limbs).
2)Mollusks: snailes, slugs, clams, octopuses. they have a muscular foot (siphon), hydrostatic skeleton, visceral mass (organs contained in a big mass, digestion, excretion, respiration), and have a mantle (may secrete caco3 shell).
why do arthropods and mollusks have a drastically reduced coelom?
a muscular foot(hydrostatic skeleton), exoskeleton, endoskeleton, jointed limbs, kind of take over.
what are the two major lineages of the protstome?
1)Ecdysozoans: grow by molting=SHED old exoskeleton, grow new one.e.g, arthropod.
2)Lophotrchozoans: may have feeding apparatus called a lophophore used in filter feeding (bacteria, archaea, organic debris) and trochophore larvae. E.g, mollusks.
What is holometabolouc metamorphosis?
A type of metamorphosis in whihc the animal completely changes its form.
What are the two key phyla of deuterostomes?
1)Echinoderms ("spiny-skin"): (have a reduced coelom, lost gill slits) ex: sea stars, sea urchins, sand dollars, sea cucumbers. they have a WATER VASCULAR SYSTEM (& hydrostatic skeleton) which is UNIQUE to echinoderms, tubes open to the environment, extensions called podia important to movement. They have endoskelton as structural support and protection (plates; caco3). undergo metamorphosis, juveniles for dispersal stage and adults may have different symmetry (radial symmetry in urchins)_, feeding and movement. the bilateral symmetric are larvae and cant reproduce.
2) Chordates: a. ascidians (urochordata) like tunicates, sea squirts. b. lancelets (cephalochordata) like amphioxins. c. vertebrates (craniata) they have distinguishing characteristic, the skull. ----a chordate is a chordate b/c it has 4 things: 1. notochord present (at least in embryo) which is a stiff rod that runs the length of the body, functions as a endoskeleton (humans are chordates, we have some dorsal nerve chord). 2. Pharyngeal gill slits : found in throat area, function in filter feeding (in humans in embryos, pouches exist but they never open up, in fish now, but most have turned to function for O2. 3. Central nervous system with dorsal nerve chord: transmit electrical signals processing , control movement. 4. Tail that extends past the anus: muscular, power swimming. ex: manx gene.
when were the gill slits gained and under what reasoning?
before the echinoderms (hemichordates branch off same limb as echinoderms)-it's more likely that a loss occurs than more than one gain. think common ancestor.
when were the notochord, dorsal nerve chord , and muscular tail evolved?
after echinoderms and himchordates(not considered actual chordate), before the urochordates.
The four traits of chordates carry a functional significance of what ?
filter feeding and swimming.
The hypothesis on the vertebrate jaw evolution is what and was a huge innovation in what?
from gill supports in jawless fish (like hagfish which are deposit feeders and lamphers which have raspers and are ectoparasites) and for feeding AND diversity of fish. the testable predictions for the jaws-from-gill supports is developmental homology(gill supports and jaws should arise from the same cell groups in embryos) and genetic (development of gill supports and jaws should be influenced by homologous genes).
What are the key innovations in the transition to land (tetrapods)?
1) the limb-locomotion
2)the amniotic egg: 4 internal membranes(chorion which protects everything, amnion in which the embryo is actually, and the allantois which holds waste, and yolk sac which holds nutrients), and membrane-bound water supply (albumen)and the tough waterloss-proof outer shell (fish eggs have an outer membrane).
what is the closest to the tetrapod ?
lungfish, before amphbians
In marine environments, what are the key consumers?
deuterostomes
In terms of numbers of species and numbers of individuals, which are more successful-deuterostomes or insects and other protostomes?
insects and other protostomes.
In marine habitats, what are the most important large herbivores and predators?
echinoderms and ray-finned fishes.
Ray-finned fish are a clade of the vertebrae (~24,000 exist). what is their distinguishing character?
Any of various bony fishes belonging to the subclass Actinopterygii, having fins supported by DERMAL RAYS.
Define 'Phylogeny.'
pattern of evolutionary relationships. real! everything developed from a common ancestor.
Define 'phylogenetic tree.'
hypothesis of phylogeny.
Define 'synapomorphy.'
shared-derived trait.
Define Sympleisiomorphic
shared-ancestoral characters-must be a monophyletic group in order to use the term "synapomorphy."