Speciation and Evolution

Question 1

Allopatric Speciation

Answer 1

• Parental species becomes subdivided by geographic barrier (ex: mountain)
• Divergence is due to natural selection or genetic drift

Question 2

Sympatric Speciation

Answer 2

• Reproductive isolation occurs in organisms that share the same space at the same time
• Could be due to habitat isolation

Question 3

Founder Effect

Answer 3

• Special case of genetic drift
• New population is established by a small number of individuals from a larger population
• New population does not accurately represent the original population that they came from

Question 4

Peripatric speciation

Answer 4

• Small group breaks off from the larger group and forms a new species as a result of a physical barrier (ex: mountain)
• Similar to allopatric speculation BUT one group is MUCH smaller than the other

Question 5

Perapatric Speciation

Answer 5

• A species is spread out over a large area
• Mating is restricted to those in a certain vicinity
• No physical barriers

Question 6

Convergent Evolution

Answer 6

Organisms that are not closely related independently develop similar traits

Question 7

Analogous Traits

Answer 7

Similar traits that evolved in different organisms that do NOT share a common ancestor BUT share a common function

Question 8

Homologous Traits

Answer 8

Similar traits that evolved due to a shared common ancestor BUT do NOT share a common function

Question 9

Describe the Evolution of Flightlessness

Answer 9

• Trade-offs
• Wings designed for optimal diving are energetically costly when flying
• Flight is too costly when wings are used for both swimming and flying