The Stone Age, as many of us remember learning about it in science class, was the prehistoric period in which humans began using stones for tools. And while the Stone Age for humankind is long over, new archaeological evidence confirms that chimpanzees and monkeys on three separate continents have entered a Stone Age of their own.
In Africa, Brazil and Thailand, archaeologists have uncovered stone tools that, while unremarkable to look at and only the age of the Egyptian Pyramids, are exciting for one simple reason: they were used by primate, not human, hands.
The finds have sparked an entirely new scientific field: primate archaeology.
Of course we've seen primates use tools before-who can forget the scene where Chester uses a crazy straw to save the Universe in Dude, Where's My Car? But primate tool use usually pertains to sticks and plant material, not stone.
Scientists think this might have to do with available materials. Monkeys and chimps that spend a majority of their time in the trees and upper canopy don't have as much contact with stones found near the ground.
Once a particularly clever primate discovers how to use stone, this wisdom has to be passed down through generations and to other groups of primates for it to catch on. Finding tools on three distinct continents proves to researchers that primates around the world are independently discovering how to use stone, though some groups have been observed that have passed their knowledge down for generations.
Chimpanzees in west Africa have been using stones to crack open nuts for generations.
One way researchers identify primate tools, and tell them apart from human tools of the same period, is by weight. Chimpanzees apparently prefer heavier stone hammers, with a weight between 1kg and 9kg, while humans chose stones that weighed 1kg or less. Many of the 4,300 year old hammers found by researchers weighed more than 1kg, a clear indication that they were used by primates.
But what might separate primate and human evolution isn't the physical capabilities of performing a task, many monkeys have similar small-motor skills and dexterity. Instead it's hypothesized that primate evolution may reach a stand-still due to the brain development and thought processes required to envision and then create new technologies.
Yet, according to experiments conducted by Harvard researchers, Alexandra Rosati and Felix Warneken, chimps may not be able to implement skills like cooking for themselves yet (controlling fire was another human milestone of the Stone Age) but they can already appreciate the value of cooking.
In their experiments, Rosati and Warneken introduced two 'ovens' to their chimpanzees. They weren't working ovens but when the primates put their raw foods into one specific container, it would be returned to them cooked. The second container didn't 'cook' the food and anything the primates put into it remained raw.
The chimps were given raw potato slices (to be returned 'cooked' into chips) and wood chips. It wasn't long before the chimps understood that the 'oven' was meant to cook edible foods and quickly abandoned the wood chips.
What I found remarkable was that the researchers also noted chimps trying to bring raw food from remote locations in the facility to cook in their 'oven'.
The research suggests that the possibility for brain development and growth experienced by our ancestors are present in chimpanzees as well.
"It's possible that chimpanzees – and macaques and capuchins – haven't yet reached the limits of their technological capabilities," says Michael Haslam of the University of Oxford and leader of the Primate Archaeology (Primarch) project.
What's sad is that threats of extinction could interfere with the primate's ability to complete their Stone Age and reach their full potential.
"We are shrinking their populations dramatically through habitat destruction and hunting," says Haslam. "Smaller populations cannot spread and sustain complex technologies as well as larger groups."
Considering the human Stone Age lasted roughly 3.4 million years, we may or may not get the chance to find out whether primate intellect will ever advance to meet our own.Source: Bbc | Upworthy | Wikipedia