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Flashcards in phylogeny and classification Deck (39):
1

cladistics

the way we use the characteristics of plants and animals ot figure out how relationships and characteristics evolve throughout time

2

molecular phylogeny

gene sequences and characteristics that are used to make tree

3

what is studied in the evolution of diveristy of life

history oc change

mechanisms of change (comparitve embryology and developmental genetics)

4

what is developmental biolgoy

development from a singular fertilize cell to a full adult and the genes/processes involved

5

phylogenetic tree

tree of relationships

6

monophyletic clade

a single common ancestor included in the group; all descedenets of a common ancestor
(humans and chimps form a clade)

7

paraphyletic clade

groups that do not include all, but some descdenenats of the last common ancestor (reptiles; e.g. birds not included despite sharing common ancestor to crocodiles)

8

polyphyletic clade

groups that have more than one origin

e.g. birds, bats and pterodactysla re groupted together as 'flying vertebrates'

9

cladogram

only represents the branching pattern and branch order;

but doesnt tell us the time of brancing/evolution information

is more of a hypothesis of evolitionary theory

10

phylogram

shows the information about branch lengths (quantity of evolution) AND branch order

hence the real rerpesentation of evolutionary history and time (of character development)

11

in groups

mammals and frogs are outgroups relative to the ingroup of dinorsaurs but dinosaurs and frogs are outrgorups relative to the ingroup of dinosaurs

12

what do two sistergrousp form

a monophyletic group

13

what methods can we use to recontruct the tree of life

cladistics

molecular phylogeny

phylogenic rescontruction

14

what do changing trees imply

changing evolutionary scenarios

15

why is it important to understand the evolution of characers

as there are continous changes of interpresetations of evolution

16

principle of parismony

choosing the simplest explanation, which requires the fewest assumptions, from a set of equivalent models that depic evolutionary scenarios

preferred hypothesis is the simples

characteristcs shared with a more primitive animal is the primitive state

17

origin of the principle of parsimony

medivieal philosopher william of occam; logical principle

18

symplesiomoprhies

are uniformative; as they are the primitive character
bad characater for defining a gorup

they do not prefer a tree

19

synanomorphies

are informative

shared derived characateristics
they prefer trees

20

how are new groups formed

discovered by characters only presesent in monophyletic group

21

why are shared primitive characterics bad

they dont define groups adn are uninformative

22

example of groups badly defined by shared primitive characterics

1. Reptiles; defined by symplesiomorpheis such as scales and cold blooded; but birds have lost these traits in the archosauria; birds and cocodiles have shared derived characteristics (Extra hole in skull) implying birds are reptiles

2. apes: defined by sympesiomorphies such as hairiness; but hairiness is too broad to define mamals relationsips; instead humans and chimps clsoely related but humans lost traditional ape features

23

aim of phylogentic trees and the principle of parsimony

to find lots of characteristics to find overlaps in overcomming the lack of informationg conercning parsimonous cost

24

why do we use molecular phylogeny

more accurate and sometimes morphological characterstics disagree

principle of pasrimony can also be applied to nucleoid genes

25

how does gene inheritance help in constructing trees

dna provides information

26

example of molecular data revealing information between groups

choanoflagellates are the closest relative to animals:

- gene fusion supports their close relationshio

- EGF and TK genes exist across all life but only metazoans and choanoflagalltes have a fused version of this gene that places them in a clade

27

example of where gene expression matters

HRP antibody (the horse radish peroxidase gene) only binds to a gene product in the nervous system of ecdysozoa

28

molecular phylenies determien other genetic characters like

1. Elongation factor one alpha gene is preserved in all life; the gene has slowly evolve and varies in animals, plants, fungi and bacteria which allows for out groups and ingrousp to be eaily located

for example: both animals and fungi have extra amino acids in this gene; shows a molecular synacromorphy

29

examples of reclassification

spiral cleavage + bilateraly symmetry

ecihnodrms have gained and lost bilateral symmetry

the annelids have gained spiral cleaves in the the mesoderm

30

what do changes in minctonrdial gene order tlel us

supports insect and crustacean relationships

31

classification mneonimic

kindly put candy out for good students

32

classification linnear system

life
domain
kingdom
phylum
class
order
family
genus
species

33

classification order of humans

life
domain : eukarya
kingdom : animalia
phylum : chordata; vertebrata
class : mammalia
order: primate
family: hominidae
genus: homo
species: sapiens

34

legs evolution

- legs evolved in a transition between fish and tetrapods

we know jaws evolved before legs

35

fish and bird limb evolution

fish and bird limbs start similary in early embryos but end up differnet in adults

both have similar limb buds:

gene Tbx 5 switched on in the forelimbs/hindlimbs of tetrapods and in the pectoral and pelvin fin of sih

early in development genes guided in later development manipulated stem cells in fish and bird differently

36

embryonic development

process of change between first cell ana dult;

animals different due to different modes of embryonic developmen

37

embryogenesis

new morphologies evolve by changes in embryogenesis

1. all animals start as undifferetiated unfertiilziied egg cells
2. cell divisionc auses changes in animals apperances and properties
3. final produce resutls in a differed state of development

so while embryos might be similar; different adults result

hence another mechanism and history of change

38

what do nonmorphological characteristics evolve to

behaviour

39

example of behavioural evolution

snails tentacles pulsate similar to a capterpillar

hence the Drigenia Flatworm Parasite has develoepd a dual life cycle that they infect a snail and mgirate to its tentacle to make it pulsate like a caterpillar

this results in a bird eating the snail thinking its a caterpillar and consumign the flatworm

shows evolution of behaviour change