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Flashcards in speciation Deck (34)
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1
Q

biological species concept

A
  • group of populations have potential to interbreed
  • produce fertile offspring
  • members of a species similar b/c reproduce with eachother
2
Q

Reproductive isolation

A
  • prevents members of different species from mating w/ eachother
  • prevent gene flow
  • maintain separate distinct species b/c don’t share same gene pool
3
Q

what keeps species separate?

A
  • reproductive barriers
    • isolate gene pools
    • prevent interbreeding
4
Q

prezygotic barriers

A
  • habitat isolation
  • temporal isolation (breed at diff. times)
  • behavioral isolation
  • mechanical isolation
  • gametic isolation (gametes not compatable)
5
Q

postzygotic barriers

A
  • reduced hybrid viability
  • reduced hybrid fertility
  • hybrid breakdown
6
Q

disadvantages of biological species concept

A
  • reproductive isolation cannot be evaluated in
    • fossils
    • asexual reproducing species
  • Only applied to pop. that overlap geographically
7
Q

morphospecies concept

A
  • individual species differ in size, shape or other morphological feature
  • can be widely applied w/o knowledge of gene
8
Q

disadvantages of morphospecies concept

A
  • polymorphic species may be split into two species
  • cannot ID cryptic species
  • features used to distinguish species are subjective
9
Q

polymorphic species

A

an organism having more than one adult form

10
Q

cryptic species

A

species that contain individuals that are morpholigically identical to each other but belong to different species

11
Q

phylogenetic species concept

A

ID species based on evolutionary history

12
Q

monophyletic group

A
  • an ancestral pop. plus all of its descendants
    • Aka clade or lineage
13
Q

synamporphy

A
  • trait unique to a monophyletic group
  • homologous traits inherited from a common ancestor
  • shared traits in two groups on tree
14
Q

species in phylogenetic species concept

A

smallest monophyletic group on tree of life

15
Q

Allopatric speciation

A

speciation when populations become geographically isolated

16
Q

Dispersal

A
  • allopatric speciation
    • geographic isolation and new colonization
17
Q

Vicariance

A
  • allopatric speciation
    • geographic isolation by chance separation
18
Q

sympatric speciation

A

speciation when organisms live in same place

19
Q

sympatric speciation initiated by

A
  • external events
    • disruptive selection based on ecological niche
  • internal events
    • chromosomal mutation
20
Q

Niche

A
  • range of ecological resources species can use
  • range of conditions a species can tolerate
21
Q

sympatric speciation by disruptive selection

A

prezygotic reproductive isolation due to natural selection for different niche adaptation

22
Q

polyploidy

A

error in meiosis or mitosis doubles chromosome number

23
Q

autopolyploid

A

chromosomes all come from same species

24
Q

allopolyploid

A
  • parents belong to different species mate
  • offspring w/ 2 diff. sets of chromosomes
25
Q

adaptive radiation

A

evolution of many diverse species from a common ancestor

26
Q

phylogeny

A

evolutionary history of a group of orgs

27
Q

phylogenetic tree

A
  • graphical summary of evolutionary tree
  • shows ancestor-descendant relationship
  • clarifies who related to whom
28
Q

tree of life

A

most universal phylogenetic tree

29
Q

Node

A

common ancestor point where species diverge

30
Q

homologous trait

A
31
Q

Analogous traits

A
  • Traits that look and function similarly due to similar selevtive pressure
  • not inherited from common ancestor
32
Q

convergent evolution

A

evolution of a similar trait due to similar selectionin each environment

33
Q

parsimony

A

minimizing of evolutionary changes in a tree

34
Q

artiodactyls

A

group defined by ankle bone astragalus