Lecture 27 - Evolutionary Genetics

Question 1

What is overdominance and underdominance?

L27 S6

Answer 1

Overdominance:

• heterozygote is selected for and has an advantage
• e.g. sickle cell heterozygosity due to lowered malaria susceptibility

Underdominance:
-heterozygote is selected against and has a disadvantage

Question 2

What is a special characteristic about the Mennonite community that makes it ideal for genetics research?

L27 S13

Answer 2

They have a rather closed off population

Question 3

What is evolution?

L27 S20

Answer 3

Change in gene frequency in a group over time

Question 4

What is anagenesis and cladogenesis?

L27 S20

Answer 4

Anagenesis:
-evolution within a single group over time

Cladogenesis:
-evolution resulting in the splitting of one lineage into two separate species

Question 5

What are the different mechanisms of reproductive isolation?

L27 S29

Answer 5

Prezygotic:

• ecological
• behavioral
• temporal
• mechanical
• gametic

Postzygotic:

• hybrid inviability
• hybrid sterility
• hybrid breakdown