Chapter 19 and 21: Evolution and Population Genetics

This set of flashcards includes key vocabulary and definitions related to evolution and population genetics as discussed in Chapters 19 and 21 of the AP Biology curriculum.

Fossil Records

Show changes in species over time, with deeper layers containing older fossils.

Biogeography

Study of how species are distributed geographically, suggesting common ancestry for related species found nearby.

Homology

Similar structures in different species due to shared ancestry.

Vestigial Organs

Structures that have lost their original function over time, indicating evolutionary change.

Convergent Evolution

The independent evolution of similar features in species of different lineages due to similar environmental pressures.

Analogous Structures

Features that serve similar functions but do not have a common ancestor, resulting from convergent evolution.

Natural Selection

The process where organisms with favorable traits are more likely to survive and reproduce.

Adaptations

Traits that increase an organism's survival and reproduction rates in its environment.

Heritability

The ability of traits to be passed down genetically from parents to offspring.

Gene Pool

The complete set of genetic information within a population.

Genetic Drift

Random changes in allele frequencies in small populations, which can lead to significant evolutionary changes.

Founder Effect

A decrease in genetic variation that occurs when a new population is established by a small number of individuals.

Bottleneck Effect

A sharp reduction in population size due to environmental events, leading to decreased genetic diversity.

Hardy-Weinberg Equilibrium

A condition in which a population's allele and genotype frequencies remain constant over generations in the absence of evolutionary influences.

Directional Selection

Natural selection that favors individuals at one extreme of a trait distribution.

Disruptive Selection

Natural selection that favors individuals at both extremes of trait distributions.

Stabilizing Selection

Natural selection that favors intermediate variants and acts against extreme phenotypes.

Artificial Selection

The intentional breeding of certain traits over others by humans.

Microevolution

Small-scale evolutionary changes typically observed at the level of populations.

Adaptive Evolution

Changes in a population that increase an organism's fitness in its environment, primarily through natural selection.