Is 'old man' skull evidence of caring?

The toothless skull of an early human ancestor, discovered in the Republic of Georgia, may attest to evolution's oldest known example of some kind of compassion for the elderly and handicapped in society, scientists say.

Other experts agreed that the discovery was significant but cautioned that it might be a stretch to interpret the fossil as evidence of compassion.

The well-preserved skull belonged to a male Homo erectus about 40 years old. All his teeth, except the left canine, were missing. The empty tooth sockets had been filled in by a regrowth of bone, the scientists said, indicating that the man had been toothless for at least two years before he died at what was then an old age. (The discoverers call him the "old man.")

In a report in today's journal Nature, the discovery team said the 1.77-million-year-old skull "raises questions about alternative subsistence strategies in early Homo."

Specifically, how could the man have survived that long, unable to chew the food of a mainly meat-eating society?

In interviews and the current issue of National Geographic, the paleoanthropologists said caring companions might have helped the toothless man in finding soft plant food and hammering raw meat with stone tools so he could "gum" his dinner. If so, they said, this was evidence of a kind of compassion that had been absent in the ancestral fossil record before the Neanderthals 60,000 years ago.

In the survival of the old man, Dr. David Lordkinidze said in National Geographic, "We're looking at perhaps the first sign of truly human behavior in one of our ancestors."

Lordkinidze, director of the Georgian State Museum in Tbilisi, led the international team that made the discovery at Dmanisi, a site that has already yielded several fossil skulls and skeletons that are the oldest clear evidence of human ancestors living outside Africa. They have been identified as Homo erectus, an immediate predecessor of Homo sapiens, but appear to be at an early stage of that species, leading some experts refer to it as proto-Homo erectus.

Dr. G. Philip Rightmire of Binghamton University in upstate New York, a team member who specializes in Homo erectus research, said in an interview that if the toothless individual had lived in the warmer climate of Africa, with a year-round abundance of plants and fruits, his chances of surviving unaided would have been better. But in Georgia, where winters are cold and bare of vegetation, human ancestors presumably relied mostly on a diet of meat.