Lee-Ballard Biology Vocabulary Study

Microevolution

• observable change in the allele frequencies of a population over a few generations

• a large-scale evolutionary change that occurs over long periods

• the process by which new species arise from existing species

• the genetic drift that occurs in small populations

Normal Distribution

• A distribution in a population where allele frequency is highest near the mean range value and decreases progressively toward each extreme end.

• A distribution that is uniform across all values in a population.

• A distribution that only applies to categorical data.

• A distribution where all values have the same frequency.

Stabilizing Selection

What is stabilizing selection?

• A pathway of natural selection where extreme phenotypes are favored

• A pathway of natural selection where intermediate phenotypes are selected over phenotypes at both extremes

• A process that leads to increased genetic diversity

• A mechanism that eliminates all phenotypes except the most extreme

Bottleneck Effect

• genetic drift that results from an event that drastically reduces the size of a population

• a phenomenon where a small number of individuals colonize a new area

• the increase in genetic variation due to migration

• a process that leads to the extinction of a species

Genetic Drift

• change in allele frequencies due to chance alone, occurring most commonly in small populations

• a process that leads to the adaptation of a population to its environment

• the transfer of genetic material between populations

• the increase in genetic variation within a population

Founder Effect

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

• a phenomenon where a large population suddenly decreases in size

• the process by which genetic variation is lost due to random mating

• the introduction of new genetic material into a population

Disruptive Selection

• A pathway of natural selection where the most common phenotype is favored.

• A pathway of natural selection in which two opposite, but equally uncommon, phenotypes are selected over the most common phenotype.

• A type of selection that favors intermediate phenotypes.

• A process that leads to the extinction of all but one phenotype.

Gene Flow

• gene flow

  physical movement of alleles from one population to another

• gene flow

  the process of natural selection

• gene flow

  the mutation of genes within a population

• gene flow

  the isolation of populations leading to speciation

Sexual Selection

• founder effect

• natural selection

• bottleneck effect

• mutation

Gene Pool

• collection of alleles found in all the individuals of a population

• a type of genetic mutation

• the total number of genes in a single organism

• the variety of species in an ecosystem