Question

Evolution occurs in populations of individuals. What must be true of a population for evolution to occur and how do different environmental factors affect it?

Answer 1

The three evolutionary processes that can cause evolution are,

1). Mutation

2). Migration

3). Selection

Genetic variation or Mutation: Change in base pair sequences cause mutations. The mutations may be harmful or beneficial. If the mutation is beneficial, the population must be migrated to another region to spread the beneficial alleles resulted from mutation.

Migration: Migration is the movement of large group of populations from one region to another. The migrated people tend to mate with the native people. This alters the allele frequencies in the offspring and triggers evolution. This change in allele frequencies describes the history of migration.

Selection: Natural selection is a natural process of selection of genotypes that would result in offspring with better reproductive capabilities. Natural selection is highly unpredictable and it act on pre-existing genetic variants. Natural selection always results in better survival of organism independent of its pathogenicity.