AP Environmental Science: Topic 2.6 Adaptations

Key vocabulary terms and concepts covering genetic variability, natural selection, adaptations, and evolutionary mechanisms from AP Environmental Science Topic 2.6.

Mutation

A random event that occurs when DNA is copied, which can result in an entirely new trait within an organism.

Crossing Over

The process during meiosis where exchange of genetic information occurs between parts of parent chromosomes, leading to new trait combinations.

Adaptation

A trait originating from genetic variability that is advantageous to an organism and increases its fitness.

Fitness

An organism's likelihood and ability to survive and reproduce in its environment.

Natural Selection

The process where organisms better adapted to their environment survive and produce more offspring, passing their traits on while unadapted individuals die off.

Evolution

The change in the prevalence or frequency of a trait throughout an entire population over time.

Selective Force

An environmental condition, such as predation or drought, that kills off or selects out individuals in a population that lack a specific adaptation.

Microevolution

Small genetic or physical changes occurring within a single species over time.

Daphne Major

An island in the Galapagos where average finch beak depth increased from $9.5\,mm$ in 1976 to $10.2\,mm$ in 1978 following a major drought in 1977.

Pace of Environmental Change

The rate at which an environment alters; rapid changes force species to migrate or face extinction, whereas gradual changes allow species time to adapt.

Generation Time

The lifespan and reproductive rate of a species, where shorter lifespan organisms evolve rapidly and longer lifespan organisms adapt slowly.