Youngless: Mechanisms of Evolution (What Causes Evolution)

Evolution

The process by which species adapt over time in response to their changing environment.

Natural Selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Mutations

A random change in the genetic composition of an organism due to changes in the DNA base sequence

Genetic Drift

A random change in the allele frequency of a population as a result of chance events rather than natural selection.

1. Bottleneck effect

2. Founder effect

What are the 2 types of genetic drift?

Bottleneck effect

Genetic drift resulting from the reduction of a population, typically by a natural disaster (fire, disease, volcano), such that the surviving population is no longer genetically representative of the original population.

Founders effect

genetic drift that occurs after a small number of individuals colonize a new area

Sexual Selection (non-random mating)

natural selection arising through preference by one sex for certain characteristics in individuals of the other sex.

Ex: Peacock feathers

Gene Flow

Movement of alleles into or out of a population due to the migration of individuals to or from the population