Human Evolution - Skulls
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I wrote a while ago about the debate over how long ago our evolutionary ancestors started using fire - physical evidence has generally pointed to a recent date but many believe that it had to be much earlier because it probably affected the physical evolution of our brains, teeth, and jaws. Until recently, we've only had physical evidence of fire use going back around 700,000 years. Now the date has been pushed back to about a million years.
The new evidence comes from the work of Francesco Berna of Boston University and an international team at Wonderwerk Cave in South Africa. This puts the deliberate use of fire in the hand of homo erectus.
Using a technique that allows researchers to conduct microscopic analysis of the chemical composition of a sample, Berna was able to identify burned pieces of bone and plant material in the cave's sediments. The sediment came from an excavation unit that is roughly 100 feet inside the cave, which makes it unlikely that the material was burned by a lightning strike or wildfire.
According to Berna, learning to use fire was an important turning point for our species--both evolutionarily and culturally. "Control of fire is a tool for adapting to different environments," he says. "It provides warmth, it provides light...and it keeps away wild animals."
Source: Archaeology, July/August 2012
It is believed that the use of fire for cooking played an important role in our evolution because the process has the effect of "pre-chewing" and "pre-digesting" some of the material. This both increases the amount of nutrients we can take from our food while simultaneously reducing the amount of resources needed to eat and digest them - a double benefit that no other species has developed.
This is, of course, in addition to all of the other benefits that control over fire can provide, like those mentioned by Berna.