Question

Individuals in a population of purple people earters are polymorphic at a single locus that leads to variation in purple people eater pup viability. 45% of the pups with genotype PP are viable, 54% of pups with genotype Pp are viable, but only 4% of pups with genotype pp are viable. What model of natural selection best fits these data?

Selection for a completely dominant trait OR Overdominance. WHY?

Answer 1

Ans ) here genotyle Pp that is heterozygote have 54% survival rate or fitness so they get more chance of mating and increase in number as compare to two homozygous traits, so this leads to stabilizing or normalizing selection model of natural selection as moderate trait ie heterozygotes are selected and undergo selection. So here selection of overdominance ie heterosis where  heterozygote produce better phenotype than homozygous parents and lead to heterozygote selection.