In a very large population, a quantitative trait has the following distribution pattern. If there is no gene flow, the curve shifts to the left or to the right, and the population size consequently increases over successive generations, which of the following is most likely occurring?
A) immigration or emigration
B) directional selection
C) disruptive selection
D) genetic drift

Question

In a very large population, a quantitative trait has the following distribution pattern. If there is no gene flow, the curve shifts to the left or to the right, and the population size consequently increases over successive generations, which of the following is most likely occurring?
A) immigration or emigration 
B) directional selection 
C) disruptive selection 
D) genetic drift

Quizplus · Accepted Answer

If the curve shifts consistently to one direction in successive generations, it suggests that there is directional selection occurring, favoring individuals with traits at one end of the spectrum. This would result in an increase in the frequency of those traits, which would shift the distribution of the population towards that direction. The other choices do not necessarily explain this observation.

In a Very Large Population, a Quantitative Trait Has the Following