martes, 21 de abril de 2015

Our ancestors used knives two million years ago

Thanks to new technology it has finally been determined that hominids - our primate ancestors - were making and using tools in different parts of South Africa as long as two million years ago.

This is much earlier than originally thought.

Kathleen Kuman, a professor of archaeology at the University of the Witwatersrand, and researchers have dated a collection of tools from the Oldowan (a flaked stone tool industry) found in the Sterkfontein Caves in the Cradle of Humankind, after decades of lack of clarity.

"There was no absolute dating method that worked well for the cradle sites at the time, and for many decades we relied on the age of the fauna to give us the age of tools," she says.

But a new machine designed at Purdue University in the US was able to analyse the age of the quartz stone from which the tools were made, it was announced earlier this month.

By measuring the build-up of aluminium in the quartz, the machine can determine for how long it had been buried.

"Quartz tools dominate our Oldowan assemblage at Sterkfontein," says Kuman. "They are very sharp and must have been used for cutting activities. It is commonly believed that cutting of meat from carcasses was one of the first uses of Oldowan tools."

There are also some quartzite tools which have more "robust" edges and which were probably used to scrape and cut through tougher materials.

There are three other Oldowan deposits in South Africa - another one near Sterkfontein and two in the Northern Cape - and they are from roughly the same era.

"Now that we have four Oldowan sites in South Africa, we know that the industry was present here consistently and had a fairly wide distribution from the Cradle of Humankind in Gauteng to the Northern Cape," says Kuman. Tanya Farber | timeslive.co.za