Humans and Fire

It had been conventional wisdom that the origin of bipedality occurred in a forest/fringe environment and that a move to the savannah during the dry-out at the end of the Pliocene accelerated the evolution of humans.  That was thrown into turmoil when it was discovered that Ardipithecus ramidus possessed facultative bipedal characteristics at 4.4 million years but lived in an entirely forested environment.

Now, it seems, the savannah is seen as playing a different role in human evolution.  Charles Q. Choi, of Scientific American writes:

A longtime theory holds that early humans discovered how to use fire accidentally—perhaps while making stone tools they found that striking rocks against each other could generate sparks, and then gradually learned fire had many uses.

The problem with such serendipity-based explanations is that they "raise more questions than they answer," says evolutionary anthropologist Christopher Parker at the University of Utah in Salt Lake City. For example, these theories do not address when or where the discovery might have occurred, why it did not happen earlier or why other animals that use stone tools—chimpanzees, capuchin monkeys, crab-eating macaques and sea otters are known to do so—did not also develop fire use, Parker notes.

Parker and his colleagues suggest in a study published in the April Evolutionary Anthropology that humans developed fire use as a natural response to environmental changes. Previous research found that roughly 3.6 million to 1.4 million years ago—as the genus Homo emerged in Africa—the continent regularly experienced bouts of aridity, causing forests to shrink and dry grasslands to spread. Earlier studies suggested these climate shifts may have driven humanity’s ancestors away from a life climbing trees and toward one of walking upright on the ground, Parker says.

Yes, but there have been, as alluded to above, issues with these previous studies. If bipedality originated in the forest, as a response to who-knows-what, then they already possessed it when the drying out began. But this is not the crux of Parker's research:

Parker and his colleagues suggest in the new study that our ancestors not only grew accustomed to fire but learned to exploit it as a naturally occurring resource. This adaptation, called pyrophilia, may have set the stage for more active and deliberate human use of fire.

The research team's models suggest early humans benefited from wildfires in a number of ways: The blazes would have made it easier to find food, much as Martu Aboriginal women in Australia still rely on fire to clear brush for more efficient hunting. The models also indicate that early humans might have combed the charred remains of wildfires to dine on animals, seeds, nuts and tubers cooked in the flames—benefitting from a chemical process that not only makes many foods easier to digest but kills germs and neutralizes some toxins.

This has not been proposed before and it will be interesting to see if more evidence of this is found. Read the whole thing.

First Use of Fire in Europe Later Than Thought

New Scientist is reporting that examination of the earliest evidence of controlled fire in Europe has pushed it forward in time to around 400,000 years ago. Jessica Hamzelou writes:

To try to pin down the earliest evidence of controlled fire use, Paola Villa at the University of Colorado in Boulder, and Wil Roebroeks at Leiden University in the Netherlands re-examined the data from over 100 European sites. They were looking for evidence of fires that were unlikely to have occurred naturally – those in caves, for example – and for clues that fire had been used in a controlled way. These include activities such as making pitch: some early hominins made this sticky substance by burning birch bark and using it to glue pieces of flint to wooden handles to make stone tools easier to use.

She continues:

Although Villa and Roebroeks investigated only European sites, they think evidence of controlled fire use at a number of other sites is also up for debate. The Swartkrans site in South Africa is believed by some to contain 1.6 million-year-old evidence in the form of hundreds of charred bones. "But these might just have been sporadic natural fires that were taken advantage of," says Villa. In fact, just one site earlier than the 400,000 year mark has strong evidence of controlled fire use, the pair says: the 780,000-year-old Gesher Benot Ya'aqov site in Israel.

The earliest evidence in Asia is in the Homo erectus/ergaster site of Zhoukoudian, where it is estimated to be around 400 ky also. This does, indeed, suggest that early humans use of considerable resourcefulness without the use of fire. I am betting though, that even Spain during the Mindel and Riss glaciations was pretty cold. I would not be surprised if evidence was discovered that pushes the use of controlled fire back a bit.