“Around a decade ago, koalas nearly vanished from southeastern Australia due to the fur trade. In the 1920s, as few as 500 individuals remained in the state of Victoria. Conservationists kicked off a concerted effort to rebuild their numbers, and by 2020, the local population had ballooned to nearly half a million animals.

While that’s good news, if a population gets severely reduced in a ‘genetic bottleneck,’ that usually causes descendants to have little genetic variation. This can increase their risk of inbreeding—which can lead to deformities and poor health—and leave them vulnerable to environmental pressures they can’t adapt to.

Surprisingly, DNA analyses reveal that Victorian koalas’ genetics are also quickly rebounding, probably because the population grew so fast, according to a study published March 5 in the journal Science. The findings provide hope to those working to save animals from the brink of extinction.”

From Smithsonian Magazine.