London, Aug 23 (IANS) Cooking food with fire may date back two million years, far earlier than originally thought, a study suggests.


According to the research, there is evidence that this occurred with the emergence of Homo erectus - a direct ancestor of modern humans who evolved around 1.9 million years ago, Daily Mail reported Tuesday.

Until now the earliest date accepted by scholars for when man learned to control fire is 1.5 million years B.C.

Processing food played a vital role in human evolution. By boosting calorie intake, and reducing feeding time, it would have aided fitness and survival and set the stage for evolutionary progress.

Experts calculated that if humans were ordinary primates living off raw food, eating would take up 48 percent of their day. In fact, modern humans devote just 4.7 percent of each day to the business of food consumption, the Mail said.

As well as spending much less time eating than chimpanzees and other apes, humans have also evolved far smaller teeth, jaws and guts.

The scientists say the physical changes could not have evolved without the introduction of food processing which would also have included techniques such as preserving foods with salt and drying out meats in the sun.

Like modern humans, Homo erectus had molars too small to be the product of the natural forces of evolution alone.

It spent more time eating than modern humans, but food consumption still only took up an estimated 6.1 percent of its day.

The findings have been published in the journal Proceedings of the National Academy of Sciences.

The US authors, led by Chris Organ, from Harvard University in Cambridge, Massachusetts, wrote: "Food processing would have provided higher caloric intake in the ancestors of modern humans, which likely bestowed significant advantages on reproductive success and survival."

The research involved a comparative analysis of modern humans, non-human primates, and 14 extinct hominids (human-like creatures) dating back more than five million years.

The scientists used information from tooth size, body mass, DNA and other characteristics to infer when patterns of reduced eating time began.