B y Thomas Riggins
July 17 2007
y Thomas Riggins
One of the chapters (incomplete) in Engels' 'Dialectics of Nature' is entitled: 'The Part Played by Labour in the Transition from Ape to Man'. Although this was written in the 1870s it compares well, I think, with scientific ideas that are considered new today. I propose to compare Engels' views with those reported by Ann Gibbons in an article in the June 15, 2007 issue of Science ('Food for Thought: Did the first cooked meals help fuel the dramatic evolutionary expansion of the human brain?').
This article is primarily about Harvard primatologist Richard Wrangham's theory that cooking led to the expansion of the human brain, that is, the Homo erectus brain, and resulted in the intellectual development of Homo sapiens.
Wrangham, Gibbons says, 'presents cooking as one of the answers to a long standing riddle in human evolution: Where did humans get the extra energy to support their large brains?' That is, how do we explain that while we use about the same metabolic energy (calorie burning) as apes of comparable size, 25% of our energy is used by our brain, the apes only use 8% for theirs.
Gibbons reports that a classical explanation is that by eating meat we shrank our gastrointestinal system (we need more guts to digest plants than meat, and it takes longer) and the saved energy was devoted to the brain. 'That theory,' she says, 'is now gathering additional support.'
I don't know why she calls it 'classical' because she dates it to 1995. She writes, 'Called the expensive tissue hypothesis, this theory was proposed back in 1995....' Here is Engels (who is really 'classical') in the 1870s writing about the effects of a meat diet 'shortening the time required for digestion.' Engels said, 'The meat diet, however, had its greatest effect on the brain, which now received a far richer flow of the materials necessary for its nourishment and development, and which, therefore, could develop more rapidly and perfectly from generation to generation.' In this respect, modern science has not improved on Engels!
Wrangham, Gibbons reports, 'thinks that in addition, our ancestors got cooking, giving them the same number of calories for less effort.' Wrangham first 'floated this hypothesis' way back in 1999 (Science, 26 March 1999, p. 2004). There is nothing new under the Sun. Here, again, is Engels: 'The meat diet led to ... the harnessing of fire [which] ... still further shortened the digestive process, as it provided the mouth with food already, as it were, half-digested....' Modern science is repeating the views of Engels, and the science of his day, a hundred and thirty years on.
Engels talks about the role of labor in the transition from ape to man, and we shall see that it is labor that is the basis, in humans, for meat eating and cooking. But first, some more of Gibbons.
If cooking led to the expansion of the brain (the modern way of talking about the transition from ape to man), when was the First Supper? Wrangham thinks it was about 1.6 to 1.9 million years ago [mya] and the diner as well as the chef were Homo erecti. Of course, Engels knew nothing of modern primate evolution or what a Homo erectus was, but he did think meat eating and cooking were gradually developed from ape like ancestors (along with speech and more complex thinking), so he would not have been surprised by modern theories.
The article points out that early humans (e.g., australopithecines, 4 to 1.2 mya) had chimpanzee sized brains, while H. erectus (AKA H. ergaster) had a brain twice that size (c. 1000 cc). We evolved, along with our cousins the Neandertals, around 500,000 to 200,000 years ago, with brain sizes of about 1300 cc and 1500 cc, respectively. It was meat that allowed the skull to expand for brain growth 'according to a long-standing body of evidence.' A very long standing body of evidence since it is found in Engel's article.
We are told the first stone tools, used to butcher animals, date from 2.7 mya in Ethiopia (at Gona). The cut marks on bones, adjacent fossils, etc., suggest that australopithecines were making these tools and eating meat. Wrangham thinks that H. erectus replaced raw meat with cooked meat (1.9 mya) and this accounts for the big increase in its brain size.
The problem with this theory is that evidence of human use of fire only dates from about 790,000 years ago in what is now Israel. However, this is not fatal to Wrangham's position. Evidence of human controlled fire is very hard to come by and it is quite possible that earlier evidence of fire use will be found.
Some other scientists think Wrangham is right in principle, cooking led to brain increase (as Engels said), but his timeline is off. It didn't happen by H erectus, but by H sapiens and Neandertals. The jury is out.
While the jury may be out on Wrangham, it is not out on Engels. While this article discusses meat and cooking and the theory that 'cooking paved the way for brain expansion', it mentions nary a word about the role of labor in expansion of the human brain. The real point of Engel's article should be reaffirmed.
Meat eating and cooking are secondary developments derivative of what Engels called 'the decisive step in the transition from ape to man.' This was the development of the human hand as a result of the evolution of erect posture in our ancestors. Once the hand was no longer used in locomotion, it was free to develop greater dexterity which 'increased from generation to generation'-- i.e., was selected for. 'Thus,' 'Engels writes, 'the hand is not only the organ of labour, it is also the product of labour.'
As the first hominids developed more dexterity they began to make tools and to live under more complex social arrangements, necessitating better communication skills. Thus Engels writes, 'First labour, after it and then with it speech--- these were the two most essential stimuli under the influence of which the brain of the ape gradually changed into that of man, which for all its similarity is far larger and more perfect.'
I have already mentioned above how Engels saw the adoption of meat eating and fire (cooking) as outgrowths of the labour of primitive humans in tool making (which led to hunting and fishing) which derived from the adoption of upright posture. The Australopithecines of Goma represent the earliest tool makers (hominid, that is) and if meat eating led them to develop into H. erecti, and Wrangham proves right and H. erectus was the first cook, and the H. erecti, through the use of fire and cooking, then developed into us, then modern science has validated the argument presented by Engels in his essay of the 1870s.
The prescience of Engels demands that we in the 21st Century continue to profit and learn from his writings. He closes his essay with words that are even more relevant to us today than they were two centuries ago.
After tracing the development of civilization from the time of the transition to modern humans, Engels writes about how our species thinks that it is the master of nature and that we can remake the natural world to our own specifications. But we have to be 'reminded that we by no means rule over nature like a conqueror over a foreign people ... all our mastery of it consists in the fact that we have the advantage over all other creatures of being able to learn its laws and apply them correctly.'
But will we apply them correctly? For that we must rely upon science and it doesn't look like our political and economic leaders are willing to do that, nor do the masses of people seem properly educated as to this necessity.
Engels says that while we have built up a modern civilization (industrial capitalism) by subjecting nature to our immediate interests, we have not calculated the remote long term effects of our actions. 'In relation to nature, as to society, the present mode of production is predominately concerned only about the immediate, the most tangible result....'
As long as the corporations are making their profits, as long as they sell their commodities, they do not care 'with what afterwards becomes of the commodity and its purchasers. The same thing applies to the natural effects of the same actions.'
So, here we are 130 years down the line with global warming, polluted air, mass extinctions in the plant and animal worlds facing us, and the oceans slowly dying. Engels had hoped that we would by now have had a world socialist community and these problems would not be facing us. But we don't and they are.
There is only one way to solve them, according to Engels, and it 'requires something more than mere knowledge. It requires a complete revolution in our hitherto existing mode of production, and simultaneously a revolution in our whole contemporary social order.' We had better get to work. Time is running out!