7.10: Postzygotic Barriers

Question 1

What is reduced hybrid viability?

Answer 1

• The genes of different parent species may interact in ways that impair the hybrid’s development or survival
  Ex. Domestic sheep can fertilize domestic goat, but the hybrid embryo dies early on

Question 2

What is reduced hybrid fertility?

Answer 2

A hybrid can develop into a healthy (viable) adult, but it is
sterile (not fertile)
↳ usually results due to differences in number of chromosomes between parents
Ex. A make donkey and female horse can mate to produce a mule, but mules are sterile

Question 3

What is hybrid breakdown?

Answer 3

• the hybrid of the first generation may be fertile, but when they mate with a parent species or one another, their offspring will be sterile.
  Ex. Farmers have tried crossing different types of cotton plants, but after the first generation the plants do not produce viable seeds