Unit 7 Biology Vocabulary

Natural Selection

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

Evolution

The change in the heritable characteristics of biological populations over successive generations.

Adaptations

Inherited characteristics that enhance the survival and reproduction of organisms in specific environments.

Founder’s Effect

A genetic phenomenon that occurs when a small group of individuals becomes isolated from a larger population, leading to reduced genetic diversity.

Sexual Selection

A mode of natural selection where individuals with certain inherited traits are more likely than others to obtain mates.

Homologous Structures

Anatomical features in different species that share a common ancestry, but may have different functions.

Analogous Structures

Body parts in different species that perform similar functions but do not share a common ancestry.

Derived Characteristics

Traits that are present in an organism but were absent in the last common ancestor of the group being considered.

Behavioral Isolation

A form of reproductive isolation where different species have different courtship behaviors that prevent mating.

Hybrid Breakdown

A reproductive barrier occurring when hybrid offspring are viable and fertile but their subsequent generations are inviable or sterile.

Allopatric Speciation

The process of speciation that occurs when populations are geographically isolated from one another.

Speciation

The evolutionary process by which new biological species arise.

Sister Taxa

Groups of organisms that share an immediate common ancestor and diverged from one another.

Population

A group of individuals of the same species living in the same area at the same time.

Competition

The struggle between organisms for the same resources within an environment.