Directional Selection

1

Conditions change in an environment

(eg. temperature drops)

2

Individuals with an extreme phenotype are better adapted to the new environment, making them more likely to survive and pass on their alleles to their offspring

(eg. individuals with the longest fur)

3

The frequency of that particular allele increases in the next generation

4

Over generations, that particular allele continues increasing in frequency, meaning a larger percentage of the population has the characteristic