Natural selection

Definition

Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring. It is a key mechanism of evolution, first proposed by Charles Darwin.

5 Must Know Facts For Your Next Test

1. Natural selection operates on existing genetic variation within a population.
2. It results in the differential survival and reproduction of individuals due to differences in phenotype.
3. Fitness in natural selection refers to an organism's ability to survive and reproduce.
4. Adaptations are traits that increase an organism's fitness within a given environment.
5. Over time, natural selection can lead to speciation, where new species arise from ancestral populations.

Review Questions

• What role does genetic variation play in natural selection?
• How does natural selection contribute to the process of evolution?
• What is meant by 'fitness' in the context of natural selection?

Related terms

Genetic Variation: Differences in DNA sequences among individuals in a population.

Adaptation: A trait shaped by natural selection that increases an organism's reproductive success.

Speciation: The formation of new and distinct species through evolutionary processes.