Why end of dinosaurs created new dawn for our earliest ancestors
With enormous predators such as T-Rex marching around in the daytime, it is not surprising that the first mammals chose to live under the cover of darkness.
A new study from University College London and Tel Aviv University says our ancestors did not emerge from the shadows until after dinosaurs became extinct, around 66 million years ago.
Researchers used algorithms to analyse details from 2,415 species of living mammals to reconstruct the activities of their ancestors.
They found that when the dinosaurs were wiped out, previously nocturnal mammals changed over millions of years to living primarily in the daylight.
The team found the ancestors of gorillas and gibbons were the first to give up their nocturnal activity, which fits in with the fact that their descendants - including humans - are the only mammals to see well in daylight.