Every time we slice into a steak or cut into some chicken, we’re taking part in a technological heritage that stretches back at least 3.4 million years. Back then, the only cutting implements around were sharp pieces of stone and there were no true humans around to wield them. But there were still butchers– one of our ancestral species, Australopithecus afarensis, was already using stone tools to flay meat off bones, leaving small nicks with every cut. Such marked bones have been found and they push back the earliest estimates of tool use among human ancestors by 800,000 years.

In January 2009, a team led by Shannon McPherron from the Max Planck Institute found bones which had clearly been