��������

Western Washington University associate professor of Environmental Studies Michael Medler has recently published a new hypothesis about factors that influenced human evolution.

Medler has proposed that long-burning fires caused by lava flows in the African Rift Valley may have actually played a significant role in human evolution; his research, “,” appears in the most recent issue of the online journal “.”

Medler’s research contributes to an emerging notion that human evolution has been influenced by fire. Medler offers that humans are unique in the animal kingdom because of our ability to make fire. He goes on to propose that many of the other attributes that separate us from other primates may be evolutionary adaptations that resulted from small groups living close to the fires at the leading edges of lava flows in the African Rift Valley. Access to fire could have allowed cooked food, freeing more caloric energy, leading to the development of humans’ uniquely short intestines, small mouths, and most importantly, larger brains.

Medler speculates that long before humans learned to make fire, small groups may have evolved many adaptations to living near the fires that would be constantly burning as lava flows poured into the internal basins of the African Rift. These lava flows could have provided ongoing sources of heat and ignition for these groups of hominids for thousands of years at a time. The article outlines how the location of important early human ancestors coincides with the timing and location of many lava flows.

“This ‘pyrogenesis hypothesis’ combines the ideas of other researchers, but introduces lava flows as a specific mechanism to explain our unique evolutionary history,” said Medler.

Other recent research has proposed that fire influenced human evolution. For example, in his 2009 book “Catching Fire: How Cooking Made Us Human,” Harvard’s Richard Wrangham concluded that because humans require cooked food in order to survive in the wild, we are biologically dependent on the control of fire. He argues that our ancestral association with fire became obligatory by the time of Homo erectus (one of our most important ancestors) 1.9 million years ago.

“Michael Medler's ideas are exactly the kind of innovative and scientifically reasonable proposals that are needed to provoke further investigation of the critical role of fire in the human past,” said Wrangham.

Medler is continuing his research and working with students at Western’s Huxley College of the Environment to combine maps of significant hominid archeology sites in with maps of lava flows occurring in the same locations and time spans that our ancestors where evolving.

“Speculations about the effects of fire and lava flows on human evolution” is available online at http://fireecology.net/docs/Journal/pdf/Volume07/Issue01/013.pdf. For more information, contact Michael Medler at (360) 650-3173 or Michael.medler@wwu.edu.