Examples of Oldowan chopper tools from Melka Kunture, Ethiopia (Didier Descouens/Wikimedia Commons)

Examples of Oldowan chopper tools from Melka Kunture, Ethiopia (Didier Descouens/Wikimedia Commons)

A couple of million years ago our ancient human ancestors created the world’s first tools when they broke some rocks into sharp shards so that they could slice apart and butcher game such as gazelles or zebras.

These early implements, called Oldowan tools, are the world’s oldest-known cutting devices. The term “Oldowan” is taken from the site of Olduvai Gorge in Tanzania, where the first of these tools were discovered by archaeologist Louis Leakey in the 1930s.

This particular tool technology remained pretty much the same for about 700,000 years until more advanced Acheulean tools such as stone hand axes and cleavers were developed.

An extensive new study by an international and interdisciplinary group of researchers suggests that the tools themselves became a force that drove evolution.

These primitive tools became quite popular throughout the ancient world. Because nearly everyone wanted these tools, our early ancestors had to come up with an effective way to communicate with and teach others how to make and use the tools.  This means our ancient ancestors had to develop advanced verbal skills, including language.

The researchers, writing in the journal Nature Communications, suggest the methods of communicating among some of our most ancient ancestors might have been much more complex than had been thought.  So much so that earliest concepts of teaching and perhaps even the development of some kind of a fundamental proto-language or precursor to modern language took place about 1.8 million years ago.

Four views of an Acheulean handaxe (Didier Descouens/Wikimedia Commons)

Four views of an Acheulean handaxe (Didier Descouens/Wikimedia Commons)

Study authors believe that their work offers new insight into the power of human culture to actually guide the evolutionary process.

“Our findings suggest that stone tools weren’t just a product of human evolution, but actually drove it as well, creating the evolutionary advantage necessary for the development of modern human communication and teaching,” said Thomas Morgan, lead author of the study and a postdoctoral researcher in psychology at the University of California, Berkeley.

Morgan said his team’s research shows that even our earliest predecessors were able to more effectively learn how to create and use these ancient tools if they had a teacher, especially one who was able to use language.

It’s possible that more advanced tool technology could have been devised over the 700,000 years the original tools were in use.  But, since these ancient people were still so busy coming up with language and teaching methods, Morgan and his group believes that they were unable to share any possible newer technology with others.

The research team said the development of the newer Acheulean tools about 1.8 million years ago suggests there must have been some development in communication that allowed that to happen.

Homo habilis shown in this forensic facial reconstruction were among the early hominins to devise and use primative stone tools. (Cicero Moraes/Wikimedia Commons)

Homo habilis shown in this forensic facial reconstruction were among the early hominins to devise and use primitive stone tools. (Cicero Moraes/Wikimedia Commons)

To make their findings Morgan’s group recruited 180 students from Scotland’s University of Saint Andrews so that they could teach them how to make the ancient Oldewan “flake” tools.

The researchers split the 180 participants into five different groups using various teaching methods.

One group of participants had to teach themselves since they only got to look at previously fashioned tools without the benefit of any kind guidance from the tool makers.

Another group got to watch someone make the tools and was able to interact with the person who made the tools.

For the remaining groups, teachers actually instructed them how to make the tools with more complex teaching techniques, which included just the use of gestures for one group or verbal language for the others.

Once all the participants were “taught” how to make the tools, they were then tested to see how much skill they had acquired.

The results: Those who had to figure things out for themselves or just watched someone create the tools weren’t able to acquire the needed skills as easily as others who were actually taught, especially those whose instructor used verbal language.

“Human evolution, it’s not just a story of our ancestors evolving in response to environmental conditions, but is actually the case that we made those conditions ourselves,” said Morgan.

According to Morgan, the process of humans guiding their own evolution is sometimes called “gene-culture co-evolution”.  He said that’s when our genes and our culture are evolving in response to each other in one single process.

Creating stone age tools – University of California, Berkeley Video

Dr. Thomas Morgan was interviewed about his team’s research and findings in a recent radio edition of “Science World”.

You can listen to the interview in the player below.