Microevolution and Genetic Variation

These flashcards cover key vocabularies and concepts related to microevolution and genetic variation, highlighting important definitions and processes within evolutionary biology.

Why is genetic variation important?

It is the raw material for evolution and allows for adaptive evolution under changing environments.

What creates new genetic variation?

Mutations, alteration of gene number or position, and sexual reproduction.

Microevolution

Change in allele frequencies in a population from one generation to the next.

Genotype

Genetic composition of an individual.

Phenotype

Observable characteristics of an individual.

Polymorphism

When there are two or more versions of a trait within a population.

Mutation

A change in the structure of a gene, the only way to generate novel alleles.

Genetic drift

Change in allele frequencies between generations due to random events.

Founder effect

Occurs when a few individuals separate from a source population, leading to a new population that may not reflect the allele frequencies of the original.

Bottleneck effect

Occurs when a large population is suddenly reduced to a small number of individuals, leading to the loss of genetic variation.

Gene flow

Change in allele frequencies due to input of individuals or gametes from other populations.

Natural selection

The process that favors individuals with traits that confer survival and reproduction advantages.

Directional selection

Favors individuals at one end of the phenotypic range.

Disruptive selection

Favors individuals at both extremes of the phenotypic range.

Stabilizing selection

Favors individuals in the middle of the phenotypic range.

Sexual selection

Natural selection that is related to mating success.

Intrasexual selection

Acts on traits that affect success in competition with members of the same sex for mates.

Intersexual selection

Acts on traits that affect success in being chosen for mating by the opposite sex.

Neutral variation

Genetic variation that does not confer an advantage or disadvantage in terms of survival.

Evolutionary trap

A previously adaptive choice that is no longer beneficial due to rapid environmental change.

Ecological trap

A change in the environment that can lead to poor habitat choice or behaviors that were previously adaptive.