Question

Broadly classify extinction process.

Answer 1

Ecological extinction is "the reduction of a species to such low abundance that, .... Guanacos and rheas have been classified as a low risk for global extinction, but this simplistic ...

the 7 categories of the IUCN Red List

IV. THE CATEGORIES

EXTINCT (EX) A taxon is Extinct when there is no reasonable doubt that the last individual has died. ...

EXTINCT IN THE WILD (EW) ...

CRITICALLY ENDANGERED (CR) ...

ENDANGERED (EN) ...

VULNERABLE (VU) ...

NEAR THREATENED (NT) ...

LEAST CONCERN (LC) ...

DATA DEFICIENT (DD)

Answer 2

Estes, Duggins, and Rathburn (1989) recognize two other distinct types of extinction: Global extinction is defined as "the ubiquitous disappearance of a species". Local extinction is characterized by "the disappearance of a species from part of its natural range".