The human thumb changed 2 million years ago and triggered a cultural revolution

The human thumb changed 2 million years ago and triggered a cultural revolution

The human thumb is an evolutionary miracle that allowed our ancestors to create stone tools and radically expand their food choices. A new study shows that our agile and dexterous thumbs evolved 2 million years ago, irrevocably changing the course of human history.

Many primates have active thumbs, but none of them look like ours. The human thumb, perpendicular to the others, allows for a good grip and holding of objects, which anthropologists consider a necessary physical attribute for making tools. Katerina Harvati (Katerina Harvati), the lead author of the new study and paleoanthropologist at the University of Tübingen, said that most studies on the history of dexterity of ancient people are based on a direct comparison of the hand of modern humans and the hands of the first hominins. A new study shows that it was a change in the thumb that transformed humanoids into us.

Homo sapiens appeared about 300,000 years ago. Other humans (now extinct) such as Homo habilis, Homo erectus, Homo naledi and Homo neanderthalensis appeared much earlier, about 2.8 million years ago. And already after 800,000 years, they developed “opposable thumb”.

The results showed that all Pleistocene humans evaluated in the study showed an increased efficiency of thumb oppositions, and this underlines “the importance of this functional feature in the biocultural evolution of our species”.