AP Environmental

Biodiversity

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

genetic diversity

the variety of DNA (traits) within a given species

species diversity

the number and relative abundance of species in a biological community

ecosystem diversity

variety of habitats, living communities, and ecological processes in the living world

theory of island biogeography

demonstrates the dual importance of habitat size and distance form the mainland in determining species richness

species richness

the number of different species in a community

species evenness

relative abundance of each species

ecological succession

the predictable replacement of one group of species by another group of species over time to create a gradual change over time

primary succession

establishment of an ecosystem that occurs on surfaces where no soil exists

secondary succession

reestablishment of a damaged ecosystem in an area where the soil was left intact

Evolution

the gradual change in a species over time

Adaptation

inherited characteristic that increases an organism’s chance in survival

Mutation

change in DNA sequence that affects genetic information

geographic isolation

physical separation of a group of individuals from others of the same species that can lead to speciation

Speciation

Formation of new species

Simpson’s Index of Diversity Equation

n= number of individuals in a species

N= total number of organisms in the community

Shannon-Wiener Index Equation

pi= proportion of each species (n/N)

In pi = natural logarithm of pi

divergent evolution (adaptive radiation)

when two or more species sharing a common ancestor become more different over time

convergent evolution

process by which unrelated organisms independently evolve similarities when adapting to similar environments

Coevolution

process by which two species evolve in response to changes in each other due to a close mutualistic relationship

edge effect

the condition in which, at ecosystem boundaries, there is greater species diversity and biological density than there is in the heart of ecological communities

Microevolution

evolutionary change within a species or small group of organisms, especially over a short period.

Macroevolution

large-scale evolutionary changes in species that take place over long periods of time

ecological tolerance

the range of conditions, such as temperature, salinity, flow rate, and sunlight that an organism can endure before injury or death results

climax community

a stable, mature community that undergoes little or no change in species over time; has high biodiversity and high stability

pioneer species

first producer to populate an area during succession