Mammals started being active in the daytime about 66 million years ago when dinosaurs were wiped out, say scientists who suggest that our ancestors emerged from the shadows only when their vicious, giant predators disappeared. A long-standing theory holds that the common ancestor to all mammals was nocturnal, but the new discovery reveals when the mammals started living in the daytime for the first time. Using computer algorithms they reconstructed the likely activity patterns of their ancient ancestors who lived millions of years ago. Two different mammalian family trees portraying alternative timelines for the evolution of mammals were used in the analysis. The results, published in the journal Nature Ecology and Evolution, show that mammals switched to daytime activity shortly after the dinosaurs had disappeared.

Source: dna November 07, 2017 06:11 UTC