Man's first cooked meal was carrion al fresco, grilled roots and beans

Scientists believe they have identified when man ate his first cooked meal - a barbecue of root vegetables, beans, seeds, and strips of carrion meat.

The meal was devoured 1.9 million years ago in Africa, according to a team of five anthropologists who have found evidence of bone or horn digging-tools used to dig up the roots, and of 400C fires.

The team, led by British anthropologist Professor Richard Wrangham, claims that the first meal marked the beginning of humanity because of the effect it had on the development of man. The first cooked meal led to the domestication of early women as cooks, and to physical changes in man, including smaller teeth and guts, and bigger brains. The team claims that the evolution of human sexual relationships, bonding and mating will have to be re-thought.

The date at which ancestral man first used fire to cook is one of the most important missing dates in the evolution of mankind. "It is an extremely important date, but until now we have had no real idea of when it was," said Professor Wrangham, professor of anthropology at Harvard University.

"Cooking would have had a widespread effect on all aspects of life, nutrition, ecology, production of energy, and social relationships in whatever species invented it. In effect, humanity began with cooking."

"We suggest that cooking was, for example, responsible for the evolution of the unusual human social bonding of pairs within communities," he added. "It would also have fundamentally changed lifestyles. When only raw food was available, man would have had to spend half the day chewing. Cooled food also enabled mothers to shorten the period of weaning."

To track down the date of the first cooked meal, Professor Wrangham and Professor David Pilbeam and colleagues looked for evidence of the changes that cooking would have brought about.

What they found from fossil research was that there were big changes 1.9 million years ago. One of the most striking was a big reduction in molar size, and a similar drop in the thickness of tooth enamel and jaw size.

The arrival of cooking also meant that smaller guts were required to hold less food for shorter periods, and the team found stomach size did begin to shrink substantially 1.9 million years ago. Brain size also began to increase as a result of the extra energy available from more food being eaten.