AP BIOLOGY

Detailed explanation-1: -Extinction occurs when species are diminished because of environmental forces such as habitat fragmentation, climate change, natural disaster, overexploitation by humans, and pollution, or because of evolutionary changes in their members (genetic inbreeding, poor reproduction, decline in population numbers).

Detailed explanation-2: -Under the Endangered Species Act (ESA), plant and animal species may be listed as either endangered or threatened. “Endangered” means a species is in danger of extinction throughout all or a significant portion of its range.

Detailed explanation-3: -There are two main types of extinction: Mass extinction and background extinction.

Detailed explanation-4: -Species endangerment and extinction have three major anthropogenic causes-overhunting or overharvesting; introduction of nonnative species, including the spread of disease; and habitat degradation or loss. All three causes probably were factors in prehistoric as well as modern times.

Detailed explanation-5: -Locally extinct This isn’t an IUCN category, but a term meaning an animal is gone from part of its native range. Grizzly bears are locally extinct in California, but still live in the wild in other areas.