ancestor

These ancient implements -- essentially the first multi-purpose "Swiss Army knives" made by hominins -- show that our ancestors not only adapted to extreme change but prospered during one of Earth's most unstable eras.

These early humans are thought to have lived alongside their evolutionary ancestors: a pre-human group, called australopithecines, who had larger teeth and a mix of chimpanzee and human traits.

"We got interested in this because other researchers, for years, have been describing this type of ecological memory of soil microbes having some way to remember from their ancestors' past," she said.

"These are our ancestors, and we explain that no-one wants someone to fiddle or play with the skull of their grandmother."

As techniques in paleoproteomics continue to advance, researchers expect more revelations about the distant ancestors who shaped the human story.