Question

What is transitional polymorphism?

Answer 1

Transitional Polymorphism:

1. When two or more phenotypes that are visibly different occur in the same population of a species, this is referred to as polymorphism.
2. Polymorphisms demonstrate the presence of many alleles for a particular gene in the gene pool.
3. Transitional Polymorphism occurs when a gene pool contains two alleles and one allele is gradually displacing the other.
4. This results from directional selection that removes one allele from the gene pool as a result of significant environmental pressure.
5. Examples include the peppered moth's light- and dark-melanistic variations (direction of selection determined by environment)