Question

Peacocks (the males) have very long feather trains, while peahens (the females) do not. Why don’t the feather trains just get longer, and longer, and longer every generation? What would happen if the females preferred feather trains that gave the males the best or most efficient flying ability?  
This chapter deals with genetic variation and natural selection.

Answer 1

The male's feathers do not get longer and longer each generation because they would reach a point in which the feathers would hinder their survival. If the females preferred feather trains that would help males fly, then males would likely have much shorter feather trains.