Evolution Study Guide

A comprehensive set of vocabulary flashcards covering the key concepts, mechanisms, and patterns of evolution as described in the lecture notes.

Natural selection

A process in which variations that increase reproduction are greater in the next generation; it works on existing variations.

Artificial selection

The process of selection directed by humans to produce specific traits in offspring.

Heritability

The ability of a trait to be passed down from one generation to the next.

Variation

The differences in physical traits of an individual from the group to which it belongs.

Overproduction

The struggle for survival that occurs when a population produces more offspring than the environment can support.

Limited resources

Environmental constraints such as food, water, and shelter that lead to competition among individuals.

Competition

The struggle between organisms to survive in a habitat with limited resources.

Fitness

A measure of the ability to survive and produce more offspring relative to other members of the population.

Adaptations as Compromises

The concept that evolution does not work for perfection; instead, structural and functional traits involve trade-offs.

Fossils

Visible evidence of evolution representing preserved remains or traces of organisms from the past.

Biogeography

Evidence for evolution based on the study of the distribution of organisms around the world.

Embryology

The study of embryos and their development which provides evidence for evolution.

Homologous structures

Anatomical features that are similar in structure but appear in different organisms and have different functions.

Analogous structures

Anatomical structures that perform a similar function but are not similar in origin.

Vestigial structures

Remnants of organs or structures that had a function in an early ancestor but no longer serve a useful purpose.

Mutation

A random change in the DNA of a gene that acts as a source of genetic variation.

Recombination

The process of forming new combinations of alleles during meiosis, contributing to genetic variation.

Directional selection

A type of selection that favors phenotypes at one extreme of a trait's range.

Stabilizing Selection

A type of selection where intermediate phenotypes are favored and become more common in the population.

Disruptive selection

A type of natural selection in which both extreme phenotypes are favored, while individuals with intermediate phenotypes are selected against.

Gene Flow

The movement of alleles from one population to another.

Genetic Drift

A change in allele frequencies due to chance.

Bottleneck Effect

Genetic drift that occurs after an event greatly reduces the size of a population.

Founder Effect

Genetic drift that occurs after a small number of individuals colonize a new area.

Sexual Selection

A process that occurs when certain traits increase mating success.

Hardy-Weinberg

A principle describing the five factors that lead to evolution in a population.

Speciation

The rise of two or more species from one existing species.

Extinction

The elimination of a species from Earth.

Reproductive Isolation

A state that occurs when members of different populations can no longer mate successfully with one another.

Prezygotic Isolation

Barriers that prevent fertilization from occurring between different species.

Postzygotic Isolation

Barriers that occur after fertilization, preventing hybrid offspring from surviving or reproducing.

Allopatric Speciation

Speciation that occurs when biological populations of the same species become isolated due to geographical changes.

Sympatric Speciation

Speciation that occurs while populations remain in the same geographic area.

Behavioral Isolation

Isolation caused by differences in courtship or mating behaviors.

Geographic Isolation

Isolation that involves physical barriers that divide a population into two or more groups.

Temporal Isolation

Isolation that exists when timing prevents reproduction between populations.

Convergent Evolution

Evolution toward similar characteristics in unrelated species.

Divergent Evolution

Evolution toward different characteristics in closely related species.

Coevolution

The process in which two or more species evolve in response to changes in each other.

Evolutionary Arms Race

A pattern of coevolution where each species responds to the other's adaptations with its own counter-adaptations.