variations on ancestral themes reading Flashcards Preview

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Flashcards in variations on ancestral themes reading Deck (29):
1

prostomes
examples

nematodes arthopods and oncyohophorans

flatworms annelids and molsucs

2

deuterstomes
examples

hemichordates
echinoderms
chordates

3

urbilateria

common ancestor to bilateria
genes lost by individual phyla in evolution

4

evodevo

evolution and developmental viology balidates thro gene analsis to determine classification

5

drosophila and xenopos

have same hox genes that control antero posterior axis

have chordin bmp gene networks that determines dorsal ventral development

6

prostomes vs deutersomtes

prostomes; mouth at blastophore, mouth first, ventral nerve cord

deutersomes; mouth second, anus at blastopore, dorsal nerve cord

7

prostomes subspecies

ecydozoa and lophotrochozoa

8

ecdysozoa

arthopods nematodes oncyhophorans

9

lophotrochozoa

flatwoms anneilids chordates molluscs

10

snowball earth scneario

glaciation period 550 mya that decreased biological activity and cause selecte bottlenecks, after which radiation of metazoa occured

11

animals evolution

biologically geographically isolated

evolution through genetic evolution

after snowball earth; environment warmed up and intense disepred evolution and gene loss

12

genetic tool kit

urbilateria as common ancestor to bilateria

13

ep lewis

diveored genes control fly ambomdinal segements through colinearity (anterior posterir axis expression)

14

lost genes of urbilateria examples

c elegans and drosohpila lose genes in lophotrochozoa and chordates

15

nematostella vecetensis

sea anmon; cnidarian believed to have diverged from bilateria

16

scott-gehring

discovering homeovox genes

17

homeobox genes

originate in urbliateria
common to grogs and fruit fly developmental genes! all arthopods have similar set

18

mutations and hox genes

mutations cause genes to have different morphological outcomes leading to variation; hence many animal features share historical genetical homologies

19

segmentation in invertebrates

parasegmentation

20

segmentation in vertebrates

segments from sclerotome

21

mouse mesoderm

hox gene xpression correponds to somite borders

22

chordin bmp pathway

dorsal ventral axis
; chordates form CNS from ecoterm and mesoderm forms notochord

xenopus/zebrafish; celldifferentation involve ventral bmp and dorsal chordin genes

23

homologos of chordin dmp in drosophila

dpp and sog gene

24

ancestry of bilaterian cns

in chordates forms dorsally and in prostomes forms ventrally

25

pax6 gene

regulator of eye developmnt

26

hemichordates and pax6

lost neural centralizations secondarily and urblaiters organised CNS

27

genetic toolkit urbilateria

natural seection created diversity but pax 6 genes and hox genes are homolougously brought out by ENVIRONMENTAL constraints causing mutations

28

hox genes and convergent evolution

functional needs (wings of pterodactyls and birds); hence same genes cause the different analogous mutations

29

designated parallellism

converent evolution caused by parallel natraul selection of ancestral gene networks