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

The correct answer is - overdominance.

Explanation:

In the given question, genotype Pp is a heterozygote condition that has a 54% survival rate or fitness thus these individual people get more chance of mating and increase in number as compared to the other two conditions of PP or pp traits where PP has 45% survivability, less than heterozygous condition and more than pp that has only 4% rate.

It results in a normalizing selection model of natural selection as a moderate trait, that is heterozygote, is selected. Thus, the selection of overdominance which means heterozygote condition produces a better phenotype than PP or pp parents is heterosis.