October 10, 2007
Olduvai Gorge and the Origins of Human Distinctiveness
Robert J. Blumsenschine
Professor of Anthropology, Rutgers University
Minutes of the Fourth Meeting of the 66th Year
President Giordmaine called the fourth meeting of the 66th year to order at 10:15 AM and himself presented the invocation in a fine bass voice. About 85 members attended, hearing Jerry Freedman read minutes of the last meeting in a version which, in accordance with newly-set policy, beat the five-minute limitation by at least a minute.
Philip Cruikshank introduced his wife Natalie as a visitor. The president made an announcement about handbooks being available for members without them and took the opportunity to compliment the membership committee for all the effective and – from the sustained applause greeting his words – much appreciated work they have been doing under the leadership of Charles Stenard.
Philip Cruikshank introduced the speaker, Robert J. Blumenschine, since 1985 Professor of Anthropology and head of the Centre for Human Evolutionary Studies at Rutgers, whose talk was entitled “Olduvai Gorgeand the Origins of Human Distinctivemess.” The speaker proved to know what he was talking about, having spent twenty-five years working at the Olduvai Gorge on the edge of the vast Serengeti plain in northern Tanzania. He discussed the evolution of human behaviour and he used power-point with great effect, showing explanatory graphs and pictures rather than simply projecting words already uttered, as is often irritatingly the case with users of that technology.
The talk reminded me of the novels of Aaron Elkins about a “bone detective” in that by examining the marks on humanoid bones at different stages of development, he was able to delve the mystery of the diet, ranging and technological strategies of hominids. This involved gathering evidence: did animals chase hominids, or vice versa. The Olduvai basin was selected, not because large numbers of hominids lived there – they didn’t – but because its volcanic geology had evolved in such a way as to permit examination of stratified layers in useful time sequences over the last two million years, a fact successfully exploited by the pioneering work of Louis and Mary Leakey, British anthropologists from Kenya and London who began working in 1935. They were paleoanthropologists and studied the circumstances under which human behavioural traits arose.
It seems our ancestors were at first mainly vegetarians but evolved into predators of animals often larger than themselves. Our ability to move fast on two legs, to think out hunting strategy due to the leap forward in our brain size about two million years ago, and our use of language allowing co-operation, were all important in becoming successful carnivores after we and the chimpanzees branched off from our common ancestors seven-to-ten million years ago. Evidence for “homo habilis”, as he is called, and his stone tools, comes from about fifty bone specimens found in sub-Saharan Africa. Beginning in the 1950s, man was seen as a hunter but in the 1980s this was questioned in favour of man-the-scavenger, that is, not men chasing live animals but men picking up the edible leavings of prey killed by animals. It seems that, compared to us, the relatively small size of the brains and body, combined with the presence of marks of animal attack, call the hunter image into doubt.
Two kinds of scavenging were mentioned – “confrontational scavenging” where man drives away the animals who have done the work, and “passive scavenging” where men make use of food abandoned by animals. Resolving this matter was the subject of the speaker’s doctoral studies. He spent a year observing animals who deposited food at ground-level, and also leopards who stashed small prey in trees, abandoning food for long periods and allowing hominids, much better at climbing trees than we are, to find them. He concluded that the bone evidence favours the passive scavenging thesis rather than the hunting or confrontational scavenging models.
His recent study has focussed on behaviour such as the willingness of homo habilis to transport stone for tools over long distance and whether they were at risk in their passive scavenging. They were, as their avoidance of high-risk situations indicates, and even crocodiles were a danger. Large animals, if not crocodiles, were both pursuers and pursued. But only homo habilis went after the highly nutritious bone marrow, easily extracted by their tools.
Questions revealed that the animal population has been dropping off rapidly and that cannibalism is found only in the last 200,000 years. The meeting adjourned at 11:28 a.m.
Respectfully submitted,
John Frederick
Philip Cruikshank introduced his wife Natalie as a visitor. The president made an announcement about handbooks being available for members without them and took the opportunity to compliment the membership committee for all the effective and – from the sustained applause greeting his words – much appreciated work they have been doing under the leadership of Charles Stenard.
Philip Cruikshank introduced the speaker, Robert J. Blumenschine, since 1985 Professor of Anthropology and head of the Centre for Human Evolutionary Studies at Rutgers, whose talk was entitled “Olduvai Gorgeand the Origins of Human Distinctivemess.” The speaker proved to know what he was talking about, having spent twenty-five years working at the Olduvai Gorge on the edge of the vast Serengeti plain in northern Tanzania. He discussed the evolution of human behaviour and he used power-point with great effect, showing explanatory graphs and pictures rather than simply projecting words already uttered, as is often irritatingly the case with users of that technology.
The talk reminded me of the novels of Aaron Elkins about a “bone detective” in that by examining the marks on humanoid bones at different stages of development, he was able to delve the mystery of the diet, ranging and technological strategies of hominids. This involved gathering evidence: did animals chase hominids, or vice versa. The Olduvai basin was selected, not because large numbers of hominids lived there – they didn’t – but because its volcanic geology had evolved in such a way as to permit examination of stratified layers in useful time sequences over the last two million years, a fact successfully exploited by the pioneering work of Louis and Mary Leakey, British anthropologists from Kenya and London who began working in 1935. They were paleoanthropologists and studied the circumstances under which human behavioural traits arose.
It seems our ancestors were at first mainly vegetarians but evolved into predators of animals often larger than themselves. Our ability to move fast on two legs, to think out hunting strategy due to the leap forward in our brain size about two million years ago, and our use of language allowing co-operation, were all important in becoming successful carnivores after we and the chimpanzees branched off from our common ancestors seven-to-ten million years ago. Evidence for “homo habilis”, as he is called, and his stone tools, comes from about fifty bone specimens found in sub-Saharan Africa. Beginning in the 1950s, man was seen as a hunter but in the 1980s this was questioned in favour of man-the-scavenger, that is, not men chasing live animals but men picking up the edible leavings of prey killed by animals. It seems that, compared to us, the relatively small size of the brains and body, combined with the presence of marks of animal attack, call the hunter image into doubt.
Two kinds of scavenging were mentioned – “confrontational scavenging” where man drives away the animals who have done the work, and “passive scavenging” where men make use of food abandoned by animals. Resolving this matter was the subject of the speaker’s doctoral studies. He spent a year observing animals who deposited food at ground-level, and also leopards who stashed small prey in trees, abandoning food for long periods and allowing hominids, much better at climbing trees than we are, to find them. He concluded that the bone evidence favours the passive scavenging thesis rather than the hunting or confrontational scavenging models.
His recent study has focussed on behaviour such as the willingness of homo habilis to transport stone for tools over long distance and whether they were at risk in their passive scavenging. They were, as their avoidance of high-risk situations indicates, and even crocodiles were a danger. Large animals, if not crocodiles, were both pursuers and pursued. But only homo habilis went after the highly nutritious bone marrow, easily extracted by their tools.
Questions revealed that the animal population has been dropping off rapidly and that cannibalism is found only in the last 200,000 years. The meeting adjourned at 11:28 a.m.
Respectfully submitted,
John Frederick