Question

In parapatric speciation, _________ selection must be strong to counteract the effects of ________.

a) disruptive; ecological isolation

b) stabilizing; behavioral isolation

c) directional; overdominance

d) directional; gene flow

e) disruptive; gene flow

Traits for immune system responses to new pathogens are often ____ in human populations.

a) under strong frequency-dependent selection

b) rapidly lost

c) under purifying selection

d) rapidly fixed

e) correlated with other endemic diseases

The mode of speciation in which genetic drift plays the strongest role is

a) autopatric

b) purifying

c) allopatric

d) stabilizing

e) parapatric

Answer 1

1.Correct answer is:e) disruptive; gene flow

Reason:In parapatric speciation, disruptive selection drives the process of assortative mating that eventually leads to complete reduction in the process of gene flow.

2.Correct answer is: a)under strong frequency-dependent selection

Reason:Immune response traits are under frequency dependent selection.

3.Correct answer is: c) allopatric

Reason:In peripatric which is a subform of allopatric mode of speciation, the genetic drift plays a significant role.