Until Now
Biology

Monkeys displace the apes

Old World monkeys diversify sharply as apes collapse — and the likely reason is digestion.

When
Duration
3.7 million years
Known to
± 1 million years
Era
Miocene, Cenozoic

From about 9 million years ago the ape genera of Eurasia disappear one by one as forests fragment and become more seasonal, while cercopithecoid monkeys diversify explosively into the same regions. The leading explanation is dietary: many monkeys can ferment unripe fruit and leaves in a specialised foregut, letting them exploit resources apes cannot, and they reproduce faster. By the end of the Miocene the ape radiation is reduced to a handful of surviving lineages in Africa and Southeast Asia.

Just before

Just after