AP Biology Unit 7: Mechanisms of Evolution

Evolution

Change in the genetic makeup of a population over time.

Natural Selection

The major mechanism that drives evolution by favoring individuals with advantageous traits.

Variation

Differences in traits among individuals within a population.

Heritability

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

Overproduction

Populations tend to produce more offspring than the environment can support.

Competition

The struggle for existence among individuals for limited resources.

Phenotype

The observable physical traits of an organism.

Genotype

The genetic makeup of an organism that determines its phenotype.

Selection Pressures

Factors that influence survival and reproduction in a given environment.

Abiotic factors

Non-living components of the environment such as temperature and sunlight.

Biotic factors

Living components of the environment, including predators and prey.

Fitness

An organism's ability to survive and reproduce in a specific environment.

Differential Reproductive Success

The concept that organisms with certain traits leave more offspring than others.

Directional Selection

Selection that favors one extreme of a phenotypic range.

Disruptive Selection

Selection that favors both extremes of a phenotypic range over intermediate traits.

Stabilizing Selection

Selection that favors intermediate variants and acts against extremes.

Stable Environments

Environments that lead to little evolutionary change.

Fluctuating Environments

Environments that drive rapid evolution due to changing conditions.

Artificial Selection

Process where humans breed individuals with desired traits.

Domestication

The process of adapting wild species for human use through selection.

Genetic Diversity

The variety of genetic traits within a population.

Convergent Evolution

Different species developing similar traits due to similar selection pressures.

Lamarckian Fallacy

The mistaken belief that individuals can evolve based on needs.

Adaptation

A heritable trait that increases an organism's fitness in its environment.

Acclimatization

Temporary physiological changes an organism undergoes in response to environmental changes.

VISTA

Memory aid for explaining Natural Selection: Variation, Inheritance, Selection, Time, Adaptation.