Speciation

Question 1

General lineage species concept

Answer 1

species are metapopulations that exchange alleles frequently enough to comprise the same gene pool

Question 2

Biological species concept

Answer 2

Species are groups of interbreeding populations that are reproductively isolated from other such groups

Question 3

phylogenetic species concept

Answer 3

smallest possible group descending from a common ancestor and recognizable by unique derived traits

Question 4

Isolating barriers

Answer 4

Geographic
Reproductive

Question 5

Geographic isolating barrier

Answer 5

extrinsic properties of landscape that prevent gene flow
-Allopatry
ex. elk and red deer, *Populations must be unable or unlikely to
interbreed, even if given the opportunity

Question 6

Reproductive isolating barrier

Answer 6

Features of organisms that prevent interbreeding
-effective even in sympatry

Question 7

Reproductive barriers

Answer 7

1. Finding a mate (premating barriers)
2. Forming a zygote (postmating, prezygotic
   barriers)
3. Successfully developing reproductively
   viable offspring (postzygotic barriers)

Question 8

Premating barriers

Answer 8

Timing of reproduction
ex. corals, have greater spawning times depending on time of day

pollinator isolation
ex. monkeyflower species

Question 9

Postmating-prezygotic barriers

Answer 9

Gametic incompatibility: sperm or pollen
from one species fails to penetrate and
fertilize the egg of another species

Question 10

Postzygotic barriers

Answer 10

Hybrids produced but have low fitness
– Hybrid inviability
– Hybrid sterility
– Ecological inviability
– Behavioral sterility
ex. sperm from one species of beetle will fail to penetrate the egg of another species

Question 11

basis of postzygotic isolation

Answer 11

Bateson-Dobzhansky-Muller
incompatibilties: arise from epistatic
interactions at two or more loci

Question 12

Allopatric speciation