speciation

Question 1

biological species concept

Answer 1

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

Question 2

Reproductive isolation

Answer 2

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

Question 3

what keeps species separate?

Answer 3

• reproductive barriers
  
  • isolate gene pools
  • prevent interbreeding

Question 4

prezygotic barriers

Answer 4

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

Question 5

postzygotic barriers

Answer 5

• reduced hybrid viability
• reduced hybrid fertility
• hybrid breakdown

Question 6

disadvantages of biological species concept

Answer 6

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

Question 7

morphospecies concept

Answer 7

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

Question 8

disadvantages of morphospecies concept

Answer 8

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

Question 9

polymorphic species

Answer 9

an organism having more than one adult form

Question 10

cryptic species

Answer 10

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

Question 11

phylogenetic species concept

Answer 11

ID species based on evolutionary history

Question 12

monophyletic group

Answer 12

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

Question 13

synamporphy

Answer 13

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

Question 14

species in phylogenetic species concept

Answer 14

smallest monophyletic group on tree of life

Question 15

Allopatric speciation

Answer 15

speciation when populations become geographically isolated

Question 16

Dispersal

Answer 16

• allopatric speciation
  
  • geographic isolation and new colonization

Question 17

Vicariance

Answer 17

• allopatric speciation
  
  • geographic isolation by chance separation

Question 18

sympatric speciation

Answer 18

speciation when organisms live in same place

Question 19

sympatric speciation initiated by

Answer 19

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

Question 20

Niche

Answer 20

• range of ecological resources species can use
• range of conditions a species can tolerate

Question 21

sympatric speciation by disruptive selection

Answer 21

prezygotic reproductive isolation due to natural selection for different niche adaptation

Question 22

polyploidy

Answer 22

error in meiosis or mitosis doubles chromosome number

Question 23

autopolyploid

Answer 23

chromosomes all come from same species

Question 24

allopolyploid

Answer 24

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

Question 25

adaptive radiation

Answer 25

evolution of many diverse species from a common ancestor

Question 26

phylogeny

Answer 26

evolutionary history of a group of orgs

Question 27

phylogenetic tree

Answer 27

* graphical summary of evolutionary tree * shows ancestor-descendant relationship * clarifies who related to whom

Question 28

tree of life

Answer 28

most universal phylogenetic tree

Question 29

Node

Answer 29

common ancestor point where species diverge

Question 30

homologous trait

Question 31

Analogous traits

Answer 31

* Traits that look and function similarly due to similar selevtive pressure * not inherited from common ancestor

Question 32

convergent evolution

Answer 32

evolution of a similar trait due to similar selectionin each environment

Question 33

parsimony

Answer 33

minimizing of evolutionary changes in a tree

Question 34

artiodactyls

Answer 34

group defined by ankle bone astragalus