Scientists make huge breakthrough with 3m-year-old human DNA discovery

Scientists have made a significant breakthrough in the study of the first humans on Earth, who lived approximately 2.75 million years ago. Some 1,300 ancient tools have been unearthed in Kenya, including sharp flakes, hammerstones, and stone cores, suggesting early humans were far more sophisticated than once thought.

The same kinds of tools appear in three distinct layers underground in Namorotukunan, a significant archaeological site in the Turkana Basin of northwest Kenya, with each layer dating back further in history, suggesting that humans continually used tools hundreds of thousands of years earlier than previously thought.

The collection completely blows previous understandings of early humans out of the water, because many experts in human evolution believed that continuous tool use emerged much later, between 2.4 and 2.2 million years ago.

"We have probably vastly underestimated these early humans and human ancestors. We can actually trace the roots of our ability to adapt to change by using technology much earlier than we thought, all the way to 2.75 million years ago, and probably much earlier," said Prof David Braun of George Washington University, who led the research.

These very first humans are believed to have had relatively small brains, and coexisted with a pre-human group known as australopithecines, which had larger teeth and a mix of chimpanzee and human traits.

The tool users at Namorotukunan were most likely one of these groups or possibly both, as published in the journal, Nature Communications.

Prof Braun explained that previously, tool use was linked to when humans had evolved relatively larger brains. "But what we're seeing at Namorotukunan is that these really early tools are used before that brain size increase," he said.

"The argument is that we're looking at a pretty substantial brain size increase. And so, often the assertion has been that tool use allowed them to feed this large brain," he said.

Scientists believe the tools would have helped them adapt, enabling them to find food and survive in a changing landscape, ranging from lush wetlands to dry, fire-swept grasslands and semideserts.

The tools, unearthed by scientists over 10 years, would have been made in a technique known as Oldowan, where makers carefully struck rocks gathered from riverbeds.

"We thought that tool use could have been a flash in the pan and then disappeared. When we see 300,000 years of the same thing, that's just not possible," Prof Braun added.