Greek mythology has bequeathed the figure of Prometheus to us, the one that stole the fire from the gods and gave it as a gift to human beings. Since then, this character has become a symbol of the material progress of humanity, inspiring tragedies, poems, novels, films, and, of course, scientific papers. But these days, the feature that probably best represents the evolution and promises of our technological capacities is artificial intelligence. Recently, in the northern plains of modern Israel, biochemists and archaeologists have had the opportunity to link both the power of fire and the power of AI in an effort to better understand how, about a million years ago, our ancestors started giving the first steps towards the global civilization of Homo Sapiens we are today.
Becoming human: the importance of fire in our evolution
Archaeologists from Harvard University believe that the mastery of fire played a key role in the evolution line that led from the first subspecies of hominins to modern human beings. According to them, the capacity to cook meals is very likely to have paved the way for the mutations and natural selection processes that led to the emergence and dominion of Homo Sapiens – mainly by determining the gradual development of both smaller guts and much larger brains.
For decades now, we have known that the Homo Erectus, a type of archaic human that appeared about 2 million years ago, was able to develop a variety of stone tools that were mainly used for hunting small prey or cutting the carcasses of scavenged large animals. Archaeologists have discovered that fire was applied to these tools, especially to those made of flint, to chip them and shape them more easily. But the problem was that, until recently, it was very difficult to determine whether or not a certain tool had ever been touched by the flame (maybe hundreds of thousands or even millions of years ago).
AI in the campfire: searching for invisible marks in the stone
The Evron Quarry is an archaeological site in northern Israel believed to be inhabited by Homo Erectus. Back there in the 1970s, archaeologists discovered a wide array of flint stone tools, such as small and retouched flakes, cores, and hand axes, as well as bones belonging to large mammals such as hippos and elephants. But until now, except for a mysteriously burned elephant tusk, they had found no evidence of fire on the site.
Even though it is known that fire has the effect of altering the atomic structure of certain elements, most of the evidence it leaves is not only invisible but rather hard to detect, even with advanced technologies. Archaeological biochemists from the Weizmann Institute experimented by heating flint, then applying spectroscopic techniques to identify and measure how the stone was altered by the action of fire. The problem was that the patterns in the data were so complex that their analysis went beyond the possibilities of the human mind.
This is where AI kicked in. Researchers devised an app that, with the aid of a technique called ultraviolet Raman spectroscopy, could distinguish which pieces of flint had been exposed to fire and which had not, and even the temperature at which they were burned. Then, investigators applied the same technique to pieces of stone tools and bones discovered in the Evron Quarry in the 70s and were able to determine that they had been exposed to temperatures as high as 600°C. Burned bones and tusks may suggest that these animals were indeed cooked by the groups of Homo Erectus that passed through Evron Quarry about a million years ago, making it one of the oldest known cooking sites in the world.
From Fire to AI: glimpses of the future
While its reliability is still to be confirmed, this technology has the potential to change and dramatically expand what we know about how our ancestors tamed and exploited fire more than a million years ago. The excitement around this is not hard to understand: it all started there, in these ancient campfires where male and female hominins cooked their meals and shaped their tools.
At first, sitting around the fire more than a million years ago, they may have experienced something somewhat similar to our feelings when we see the fast evolution of AI today: a sense of something approaching that was beyond anything they could even imagine.
Stay tuned for more interesting blogs!