Evolution Study Guide

These flashcards contain key vocabulary terms and their definitions related to evolution, providing a comprehensive study tool.

Theory

A well-substantiated explanation of an aspect of the natural world.

Inference

An idea or conclusion that's drawn from evidence and reasoning.

Observation

The use of one of the senses or measurement to gather information.

Hypothesis

A testable statement about the relationship between two or more variables.

Law

Statements based on repeated experiments or observations that describe or predict a range of natural phenomena.

Co-evolution

Evolutionary change that occurs between pairs of species or among groups of species as they interact.

Adaptive Radiation

A process in which organisms diversify rapidly from an ancestral species into new forms.

Punctuated Equilibrium

An evolutionary change happening rapidly and in brief geological events between long periods of stasis.

Convergent Evolution

The independent development of similar traits in unrelated or distantly related species.

Gradualism

New species evolve from existing species through gradual, often imperceptible changes.

Vestigial Structures

Structures that have no apparent function and appear to be residual parts from a past ancestor.

Homologous Structures

Similar physical features in organisms that share a common ancestor, but serve different functions.

Analogous Structures

Structures that evolved independently in two organisms to serve the same purpose.

Embryology

Study of embryos of different kinds of animals that look very similar.

Fossils

Preserved remains or traces of ancient organisms.

Directional Selection

Natural selection that favors individuals at one extreme of a phenotypic range.

Stabilizing Selection

Natural selection that favors average individuals.

Disruptive Selection

Natural selection that favors individuals at both extremes of the phenotypic range.

Artificial Selection

A process where humans select which organisms get to reproduce.

Natural Selection

The process where organisms better adapted to their environment tend to survive and reproduce more.

Fitness

An organism’s ability to survive and reproduce.

Genetic Drift

Change in allele frequencies due to chance fluctuations.

Genetic Equilibrium

Allele frequencies remain constant from generation to generation.

Extinction

The death of an entire species.

Speciation

The formation of new, distinct species that are reproductively isolated.

Founder Effect

A phenomenon where a small group of individuals becomes isolated from a larger population.