Lecture 6

Question 1

Ring Species

Answer 1

Adjacent populations can exchange genetic material directly, but gene flow between distant populations occurs only through the intermediary species

Question 2

Speciation

Answer 2

• The origin of new species in evolution

- Evolution of reproductive isolation among once interbreeding populations

Question 3

Modes of Speciation

Answer 3

1) Speciation by geographical isolation (allopatric)

2) Speciation without geographical isolation (sympatric)

Question 4

Allopatric Speciation (geographic isolation)

Answer 4

1) Populations become geographically separated, preventing gene flow between them
2) As populations experience different patterns of evolutionary forces, they may accumulate genetic differences that isolate them reproductively

Question 5

2 Different ways allopatric speciation can occur:

Answer 5

1) Dispersal and Colonization: Individuals migrate to a new territory and are then cut off from the original population
2) Vicariance: Physical splitting of a habitat

Question 6

Sympatric Speciation

Answer 6

Reproductive Isolation develops and new species arise without geographical isolation
-Often requires selection for very localized specialization