Study: Ancient Humans Made Stone Axes Earlier Than Thought

A new study suggests that ancient humans were fashioning hand axes, cleavers and picks in East Africa 1.8 million years ago, at least 300,000 years earlier than previously estimated by scientists.

Homo erectus, a precursor to modern humans, appeared approximately 2 million years ago and traveled across parts Asia and Africa before dying off around 70,000 years ago. The study, published in the journal Nature, discovered huge discrepancies in tool-making technology among Home erectus based on their location.

While archeological evidence shows that Homo erectus humans in Dmanisi, Georgia, were still using simple chopping tools about 1.8 million years ago, those in West Turkana, Kenya, had developed innovative tools such as hand axes and picks - collectively known as Acheulian tools - during the same period.

The Acheulian tools represent a great technological leap. Why didn't Homo erectus take these tools with them to Asia? said study co-author Dennis Kent, a geologist at both Rutgers University and Columbia University's Lamont-Doherty Earth Observatory

A team of American and French scientists made the findings after traveling to Kokiselei, an archaeological site along the northwest shoreline of Kenya's Lake Turkana, where researchers have found some of the earliest human relics to date. By analyzing the periodic polarity reversals in the surrounding sediment, researchers discovered tools found in the area were significantly older than other Acheulian finds.

Acheulian tools previously found in Ethiopia are approximately 1.4 million years old, while experts believe similar tools found in India were made between 1.5 million and 1 million years ago.

We suspected that Kokiselei was a rather old site, but I was taken aback when I realized that the geological data indicated it was the oldest Acheulian site in the world, said the study's lead author, Christopher Lepre, also a geologist with joint appointments at Rutgers and Lamont-Doherty.

The tools were found near close to the site of Turkana Boy, the most complete skeleton of a prehistoric human found to date, which was unearthed in 1984.

While anthropologists have yet to discover an Acheulian tool gripped in a Home erectus fist, most credit those early humans with developing the technology. Acheulian tools were larger and heavier than earlier apparatuses and were likely used to hunt and butcher animals.

Home erectus was the first prehistoric human to walk upright, but possessed a flat skull, a sloping forehead and a smaller brain. They are thought to be the first humans to migrate outside of Africa.