“This site reveals an extraordinary story of cultural continuity,” Brown said in a recent press release.
When the going gets tough, the tough make the tools
The Nomorotukunan stone tool layers span the Pliocene to Pleistocene transition, during which the Earth's climate gradually became cooler and drier after a warm period of 2–3 million years. Pollen and other microscopic traces of plants in the sediments of Nomorotukunan tell the story: coastal marshes gradually dried up, giving way to arid grasslands dotted with shrubs. In a shorter time frame, hominins in Nomorotukunan faced forest fires (due to microcharcoal in the sediments), droughts, and rivers drying up or changing their courses.
“As the vegetation changed, tool production remained stable,” National University of Kenya archaeologist Rahab N. Kinanjui said in a recent press release. “It’s sustainability.”
Making sharp stone tools may have helped generations of hominins survive in a changing, drying world. During the warm, wet Pliocene, food was relatively easy to find, but as conditions became harsher, hominins likely had to scavenge or dig to obtain food. At least one animal bone at Nomorotukunan bears cut marks left by long-ago hominins who butchered the carcass for meat—something our lineage is not really capable of doing with bare hands and teeth. Tools also allowed early hominins to dig up and cut tubers or roots.
It's fair to assume that sharpened wooden sticks probably also played a role in this particular work, but according to archaeological evidence, wood won't last as long as stone, so we can't say for sure. What is some are stone tools and carved bones that hint at what Utrecht University archaeologist Dan Rolier, co-author of the paper, calls “one of our oldest habits: using technology to protect ourselves from change.”
A tale as old as time
Nomorotukunan may hint that Oldowan technology is even older than the earliest tools discovered by archaeologists so far. The most ancient tools discovered in the deepest layers of Nomorotukunan are the work of skilled flint workers who knew where to strike the stone and at exactly what angle to chip it into the desired shape. They also clearly knew how to select the right stones for the job (in this case, fine-grained chalcedony). In other words, these tools weren't the work of a bunch of apes who had just figured out for the first time how to push rocks together.
