Question

In a population of 6000 cave-dwelling fish, eyesight is under selection. Fish that are homozygous for allele A1 have good eyesight, fish that are homozygous for A2 are blind and fish that are heterozygous have poor eyesight. In the dark caves that these fish live in, the cost of good eyesight is higher than the benefits and having good eyesight is thus deleterious. Blind fish have a selective advantage of 0.25, fish with poor eyesight have a selection coefficient of 0.05. Which statement is true?

I. Fish with good eyesight have a fitness W = 0
II. The trait blindness is likely to increase in this population
I
II
Both are false
Both are true

Answer 1

Answer: I am in high school so this may not be the best answer, but I would say that eventually eye sight would simply become useless to the fish because they live in a cave and don’t really need to see, there for I would say that the second answer is correct.