Functional extinction

End of viability for a population

Functional extinction is the extinction of a species or other taxon such that:It disappears from the fossil record, or historic reports of its existence cease; The reduced population no longer plays a significant role in ecosystem function; The population is no longer viable. There are no individuals able to reproduce, or the small population of breeding individuals will not be able to sustain itself due to inbreeding depression and genetic drift, which leads to a loss of fitness.

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