Assertion: dodo's extinction | /r/CapableOf | occur over long period of time
Facets:
value: usually
type: TEMPORAL
Source sentences:
text: Extinction, though, usually occurs over a long period of time, but when it does happen at a faster rate, it is called mass extinction.
text: In summary, extinction can take place quickly like in a mass extinction, or may occur over a long period of time.