Unit 6 Evolution - Marshall Biology

Assortative Mating

Organisms selectively mate based on common phenotypes

Biochemical

Type of evidence dealing with atomic and molecular similarities

Biogeography

Study of the distribution of plant and animal species on the planet

Bottleneck Effect

Genetic drift in which only a few organisms survive a mass extinction

Descent with Modifications (DWM)

Concept that modern species are offspring of ancient species, with new traits

Directional Selection

A single extreme phenotype is favored over others

Disruptive Selection

Extreme phenotypes are favored over intermediate phenotypes

Fitness

The extent to which an organism is likely to reproduce

Fossil

Any remnant of an organism from the past that provides details

Fossil Record

History of life told through remains from the past

Founder Effect

Genetic drift in which organisms with a unique genotype begin a population

Gene Flow

The movement of alleles between populations due to migration

Gene Frequency

Percentage of times a gene or allele appears in a population

Gene Pool

All the alleles for a specific gene within a population

Genetic Drift

Changes in allele frequencies due to chance issues in the population

Macroevolution

Large scale changes in populations over long periods of time

Microevolution

A change in a gene pool over a short period of time

Mutation

Any change in DNA sequence

Natural Selection

Process of allele frequencies adapting to the needs of their environment

Random Mating

Organisms show no choice or preference on who they mate with

Speciation

Splitting of one species into two distinct, separate species

Stabilizing Selection

An intermediate phenotype is favored over others

Vestigial

Similar structures that are functional in one species but not in another