Apes Lived in Open Habitats 10 Million Years Earlier Than Expected

Well, this is rather awkward for our understanding of human evolution. New fossil evidence suggests that apes were living in open, grassland-like habitats roughly scientific discoveries keep challenging assumptions – 10 million years earlier than the prevailing narrative assumed.

The standard story goes something like this: our ape ancestors lived in forests, swinging through trees and eating fruit. Then climate change reduced the forests, forcing some apes onto the expanding grasslands. This environmental pressure drove the evolution of bipedalism – walking upright was more efficient in open terrain. Eventually, this led to hominins, then humans.

Its a tidy story. And like many tidy stories, it appears to be an oversimplification.

The new research, based on fossil analysis and paleoenvironmental reconstruction, indicates that apes were already adapted to open or semi-open habitats well before the supposed “forest to savanna” transition. They werent forced out of the trees by climate change; some lineages were already comfortable in mixed environments.

This matters because it changes how we think about selective pressures in human evolution. If bipedalism didnt evolve as a response to forest loss, what DID drive it? The answer might be more complex than climate forcing our ancestors to adapt.

Nature has ongoing coverage of human evolution research for those wanting to follow developments. One possibility is that bipedalism evolved for reasons unrelated to habitat – perhaps for carrying food or tools, perhaps for thermoregulation, perhaps for social display. The habitat argument never fully explained why only some apes became bipedal while others remained quadrupeds in the same environments.

Science progresses by overturning comfortable assumptions. This is one of those cases.