APES section E-F (Biodiversity and Evolution, Biodiversity, Species Interactions, and Population Controls)

Ecological niche

The role a species plays in its ecosystem, including how it uses resources and interacts with other organisms.

Endemic species

A species found only in one specific geographic area.

Evolution

Genetic change in a population over generations.

Geographic isolation

Physical separation of populations that prevents interbreeding.

Importance of sharks and biodiversity

Sharks regulate prey populations and maintain healthy food webs; biodiversity increases ecosystem stability and resilience.

Indicator species

Species that reflect the health of an ecosystem.

Keystone species

A species with a disproportionately large effect on its ecosystem.

Native species

Species that naturally occur in an ecosystem.

Natural selection

Individuals with advantageous traits survive and reproduce more successfully.

Nonnative species

Species introduced by humans to a new ecosystem.

Reproductive isolation

When populations can no longer interbreed and produce fertile offspring.

Species evenness

How evenly individuals are distributed among species.

Species richness

The number of different species in an ecosystem.

Climax communities

Stable, mature ecosystems that persist until disturbed.

Coevolution

Species evolving in response to each other.

Ecological succession

Gradual change in ecosystem species over time.

Generalist

A species with a broad niche and flexible resource use.

Intrinsic rate of growth (r)

The maximum population growth rate under ideal conditions.

K-strategist

Species with few offspring, high parental care, and stable populations.

Niche overlap

When species compete for similar resources.

r-strategist

Species with many offspring, little parental care, and rapid population growth.

Population patterns

Stable, Irruptive, Cyclic, Irregular changes in population sizes.

Predator-prey interactions

Relationships where predators and prey influence each other's population sizes.

Primary ecological succession

Ecosystem development on land with no soil.

Resource partitioning

Division of resources to reduce competition.

Secondary ecological succession

Ecosystem recovery where soil remains.

Specialist

A species with a narrow niche and specific resource needs.