APES Unit 2: Biodiversity

biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

generalist species

species with a broad ecological niche

genetic diversity

a measure of the genetic variation among individuals in a population

habitat diversity

the range of different habitats in an ecosystem or biome

specialist species

Species with a narrow ecological niche. They may be able to live in only one type of habitat, tolerate only a narrow range of climatic and other environmental conditions, or use only one type or a few types of food.

species richness

the number of different species in a community

species evenness

the relative proportion of different species in a given area

biogeography

study of the distribution of organisms around the world

geographic isolation

physical separation of a group of individuals from others of the same species

reproductive isolation

Separation of species or populations so that they cannot interbreed and produce fertile offspring

adaptation

A characteristic that improves an individual's ability to survive and reproduce in a particular environment.

biological evolution

the change over time in populations of related organisms

mutation

change in a DNA sequence that affects genetic information

natural selection

A natural process resulting in the evolution of organisms best adapted to the environment.

climax community

A stable, mature community that undergoes little or no change in species over time

ecological succession

gradual change in living communities that follows a disturbance

pioneer species

First species to populate an area during primary succession

primary ecological succession

ecological succession in an area without soil or bottom sediments

resilience

the ability of an ecosystem to maintain its normal patterns of nutrient cycling and biomass production after being subjected to damage caused by an ecological disturbance.

secondary ecological succession

ecological succession in an area in which natural vegetation has been removed or destroyed but the soil or bottom sediment has not been destroyed

range of tolerance

the limits to the abiotic conditions that a species can tolerate

anthropogenic

Human-induced changes on the natural environment

periodic

occurring at repeated intervals

episodic

happening in parts or segments

random

by chance, not planned or prearranged; irregular

migration

Form of relocation diffusion involving permanent move to a new location.

mass extinction

event in which many types of living things become extinct at the same time