Natural Selection and Related Concepts

These flashcards cover essential concepts related to natural selection, sexual selection, speciation, genetic drift, and phylogenetics.

Natural Selection

The process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Variation in a Trait

Differences in characteristics among individuals in a population which are crucial for natural selection.

Heritability

The proportion of trait variation attributable to genetic differences.

Agent of Selection

An environmental factor that affects the survival and reproduction of organisms, such as predators or climate.

Adaptation

A heritable trait that enhances an organism's fitness in its environment.

Directional Selection

A type of natural selection that favors one extreme phenotype over the others.

Stabilizing Selection

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

Common Garden Experiment

A method used to distinguish between genetic and environmental influences on trait variation.

Sexual Selection

A form of natural selection where individuals with certain inherited characteristics are more likely than others to obtain mates.

Male-Male Competition

Intra-sexual selection where males compete for female attention, often leading to evolved traits such as larger size or weaponry.

Direct Benefits of Female Choice

Advantages that female organisms receive from choosing male partners, such as protection or resources.

Reproductive Isolation

A condition that prevents gene flow between populations, crucial for the process of speciation.

Genetic Drift

Random fluctuations in allele frequencies in small populations that can lead to significant changes over time.

Gene Flow

The transfer of genetic material between populations which can introduce new genetic variation.

Phylogenetic Trees

Diagrams that represent evolutionary relationships among species, indicating common ancestors and speciation events.