Natural selection 1

Natural Selection

The process in which individuals with favorable inherited traits are more likely to survive and reproduce.

Microevolution

The change in allele frequencies in a population over many generations.

Adaptive trait

An inherited trait that makes an organism more fit for its environment.

Fitness

An organism's ability to survive and reproduce.

Niche

The role or function of an organism or species within an ecosystem.

Homologies

Similarities between species resulting from common ancestry.

Vestigial structure

Structures that once served important functions in ancestral species but have lost most, or all, of their original function.

Analogous structures

Similar features found in different species that are not the result of recent common ancestry.

Genetic drift

Changes in allele frequencies in a population due to random chance.

Founder effect

A phenomenon where a new population is established by a small number of individuals from a larger population.

Bottleneck effect

A drastic reduction in population size due to environmental events, leading to changes in allele frequencies.

Gene flow

The movement of alleles into or out of populations, which changes allele frequencies.

Hardy-Weinberg equilibrium

A state in which allele and genotype frequencies in a population remain constant across generations in the absence of evolutionary influences.

Common ancestor

A species from which two or more species evolved.

Sexual selection

A mode of natural selection where individuals with certain traits are more likely to successfully attract mates.

Directional selection

A type of natural selection that favors individuals at one end of the phenotypic range.

Disruptive selection

A type of natural selection that favors individuals at both extremes of the phenotypic range.

Stabilizing selection

A type of natural selection that favors intermediate variants and acts against extreme phenotypes.

Heterozygote advantage

When heterozygotes have higher fitness than both homozygotes, maintaining two or more alleles in the population.

Darwin's finches

A group of birds studied by Charles Darwin, which helped him develop his theory of evolution through natural selection.

Artificial selection

The process by which humans breed other animals and plants for particular traits.

Descent with modification

Darwin's term summarizing his idea of evolution, indicating that species change and adapt over time.