Koalas Nearly Vanished 100,000 Years Ago — And What Happened Was Unexpected

Koalas experienced a severe and prolonged population collapse beginning roughly 100,000 years ago, according to a major genomic study. The unexpected finding is that the decline started before modern humans reached Australia, challenging earlier timelines that placed people at the centre of the event.

Researchers instead found that increasing dryness, glacial conditions and shrinking forest habitat better match the ancient decline. However, “nearly vanished” describes an inferred genetic bottleneck rather than a direct count showing exactly how few koalas remained.