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41 Cards in this Set
- Front
- Back
Taxa |
named group |
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phylogeny |
a diagram depicting the evolutionary relationships among taxa- who shares a common ancestor with whom. |
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Synapomorphis |
hey are evolutionary novelties that identify these taxa as the descendants of a particular common ancestor. |
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grade |
is a level of adaption. |
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polyphyletic |
group of species with different common ansestors |
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synapomorphis |
shared derived traites |
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crown group |
a group desended from the last common ancestor of all living members of a clade |
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stem group |
group including all fossils more closely related to a particular crown group than to any other |
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parsimonous hypothesis |
parental car in archosaus |
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clades |
monophyletic groups
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monophyletic group |
contains an ancestor and all its descendants |
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Paraphyletic group |
ancestor and only some of its descendants some members of that group are more closely related to another taxon than they are to members of their own group characterized by what they lack |
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parallelism |
evolved independantly (dont owe jumping to common anscestor)We can also see reversals in evolution also called convergent evolution |
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parsimonous |
the apperance of paretnal care in the ancestor of archosaurs is the omre parsimonous hypothesis. it generates a prediction that all archosaurs |
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homoplasy |
similarity between two groups not due to common ancestry |
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who are our relatives? |
bilateria |
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true tissue |
parazoa vs eumetazoa |
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radiata vs bilateria |
2 germ layers radial symmetry vs three germ layers bilateral symmetry |
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bilateria are composed of two taxa |
protostomia and deuterostomia |
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hemichordata |
acorn worms, graptolites, and pterobrancs. free worms or simple colonial organisms |
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echinodermata |
sea stars, urchins, sand dollars, cucumbers. secondarily radially symmeteric (larvae are billateral) |
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chordata |
radial cleavage, fate of every cell devided later, blastopore becomes anus, enterocoelous (mesoderm and gut) ppharyngeal slits |
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vertebrates are in the phylum |
chrodata |
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describe chordates |
dorsal, hollow nerve chord notochord, flexible rod of tissue postanal tail endostyle |
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simple chordate design can be seen most clearly in |
cephalochordata |
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sister group subphylum |
urochordata(sessile as adults) |
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hagfish are traditionall included among _____ but teqnically _______ |
vertebrata, craniata |
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what turns generic chordate into member of craniata |
cranium, skeletal support. supports tripartite brain cranial placodes and neural crest |
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cranial placodes |
thickened patches of ectodermal tissue that will give rise to important neurosensory structures |
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neural crest |
patces of ectodermal derived cell that will migrate to other areas and form a variety of structures |
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process of evolving a more complex head |
cephalization |
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craniata show a distinctive duplication of |
hox genes- regulate expression of other genes |
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3 traits added by true vertebraes |
bony vertebae neuromasts out of cp neurally regulated hearts |
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dual nervous system |
somatic(consious) and visceral(fight of flight)(feed or breed)/autonomic |
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what supports gills
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pharyngeal arches= provide elastic recoil muscularization of pharynx |
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3 chambered heart |
sinus venosus atrium ventricle |
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cambrian explosion |
525 mill years ago, diversification evolved a couple key embryonic innovations ends in protective cranium and complex brain |
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water compared to air |
dense and viscus scatters and bends light sound travels faster conducts electricity conducts faster |
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vertebrates develop gills in pharyngeal region along |
gill arches |
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counter current system |
runs in opposite direction of blood flow |
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boyancy in early vertebrates |
be high in fat/oils or swim bladder |