|posted 1 September 2003|
William H. Calvin, A Brief History of the Mind (Oxford University Press 2004), chapter 6. See also http://WilliamCalvin.com/BHM/ch6.htm
William H. Calvin
Perhaps surprisingly, for many animal species it is not the creative component, but rather the stabilizing ratchet component, that is the difficult feat. Thus, many nonhuman primate individuals regularly produce intelligent behavioral innovations and novelties, but then their groupmates do not engage in the kinds of social learning that would enable, over time, the cultural ratchet to do its work.
— Michael Tomasello, 2000
[Our] ways of knowing and core intuitions are suitable for the lifestyle of small groups of illiterate, stateless people who live off the land, survive by their wits, and depend on what they can carry. Our ancestors left this lifestyle for a settled existence only a few millennia ago, too recently for evolution to have done much, if anything, to our brains. Conspicuous by their absence are faculties suited to the stunning new understanding of the world wrought by science and technology.
– Steven Pinker, 2002
Neanderthals and Our Pre-sapiens Ancestors
Two-stage toolmaking and what it says about thought
By about 400,000 years ago, brain size is beginning to overlap with the modern range of brain size – the average isn’t there yet, but some individuals then had brains just as large as many people of normal intelligence now have. Though Homo erectus carried on in most of Asia, there was a new species called Homo heidelbergensis in Africa and Europe, perhaps the common ancestor of both our sapiens lineage and that of the Neanderthals.
Some spectacular evidence for advanced projectile predation is seen about then, suggesting that less advanced forms had been around for some time before. One spear discovered in a coal mine at Schöningen, Germany, has a split shaft for hafting, suggestive of mounting sharp points. Found lying among stone tools and the butchered remains of ten horses in layers dated to about 400,000 years ago, there are also three wooden spears several meters long. They were made from the trunks of spruce trees that were about 30 years old. After removing the bark, they were sharpened at the base of the trunk, where the wood is hardest. The thickest and heaviest part of the carved shaft is about a third of the distance back from the spear tip.
So these three weren’t the crude beginnings of spears, of the sort useful for thrusting and keeping troublesome scavengers at a distance. Balanced like modern javelins, they were surely thrown.
The third big advance in crafting stones also occurred about this time, staged toolmaking. Like staged food preparation, it suggests that hominids had learned to think ahead and prepare an intermediate product.
Producing a sharp edge seems to have been the major preoccupation of toolmakers, starting 2.6 million years ago. Though random bashing works (shatter and search), it is wasteful of raw material and, if you don’t happen to live in the midst of plenty, you have the motivation to make your hand-carried rock produce more sharp edges than random bashing produces. And so, early on, directed blows became common. The idea may not have been to construct a particular shape of tool, so much as to get more sharp edges per rock.
The second stage, known as the Acheulean, involved both hard hammering for the basic shapes and soft hammering for the edges. The handaxe was only the most enigmatic of the Acheulean tools. This was a gradual working of the stone to achieve a desired form, though not staging per se.
What developed was a method of staging, controlling the shape of the struck-off piece so that it had two good edges in a V-shape. The knapper first shaped a rock to have two sloping platforms like a tent. Then in the second stage, the knapper would up-end this “core” and strike in a line almost parallel to the “ridgeline.” The “flakes” struck off would thus be triangular, with two sharp edges intersecting at the ridgeline. The successive flakes would get bigger as they worked down through the core. Called Levallois flakes after the Paris suburb where they were first discovered, they are also common in Africa in the same period.
Whole books are regularly written about Neanderthals, and no wonder. They represent “the path not taken” (that is, by the way, an advanced form of metaphor; more later) by our ancestors, yet a path that led to a species that thrived for a long time in Europe and the Middle East.
Did they lack our kind of hunting techniques? (They certainly suffered a lot more nonfatal injuries, and died at earlier ages, than comparable “paleoindian” populations, so perhaps they regularly got too close to thrashing animals, or regularly beat up on one another.) Did they lack our kind of tools? (That case was once made from the archaeological record, but now it seems they had comparable tools to Cro-Magnons where they overlapped in their habitats.) Could they make such tools, or just trade for them? Invent them, or only copy them?
Did Neanderthals come to a violent end at the hands of our ancestors? Die from imported Cro-Magnon diseases, the way smallpox cleared the way for European settlers in the Americas? Or were they simply outcompeted, slowly declining into disappearance as their hunting grounds shrank during a bad drought? (That’s what evolutionary theory suggests ought eventually to happen to one of two species occupying the same evolutionary niche.) There are no answers to most such questions, but “all of the above” seems likely at different times and places.
Did Neanderthals have our kind of language? A theme of many novels is the potential conflict between Neanderthals and modern Homo sapiens because one had the bleached skin of sunshine-starved Europeans and the other had the dark skins of those fresh out of sunny Africa. Cross-group romances and cross-rearing of orphans allow the novelist to show the contrasts, head to head. But the major ploy of the paleonovelist (many of whom are well informed about the anthropology) is to assume that one group had our kind of language and the other didn’t.
That is indeed a key scientific question, but no one has yet found evidence that is widely persuasive on the issue of whether Neanderthals had language. Still, the effort so far shows the candidates and they say something about what had happened in the 1.2 million years between early Homo erectus and Homo heidelbergensis.
Since women and children speak at a higher pitch than adult men, thanks to their smaller size, the hearing part of our brain needs to correct for this, so that words from a small vocal tract still are recognized as the same as the words spoken from a deeper throat. Some of the vowel sounds that we make are useful as calibration signals and cause us to treat the other speech sounds in a manner appropriate to the size of vocal tract that produced them. The upper part of the vocal tract of Neanderthals is not shaped the same as ours, judging from the curvature of the base of the skull. The argument about Neanderthal abilities has been about speech, not language per se, and has been founded on the observation that the Neanderthal throat would not have been well suited for the production of the vowels a, i, and u.
Fine, perhaps they calibrated speech sounds in some other way. Or just slowed down, the way we do when conversing with someone with a speech defect or a hearing problem. What we really want to know is how much Neanderthals and our ancestors talked and, if they could, whether they had protolanguage or, better yet, syntax.
Well, how about the size of the nerve that controls movements of the tongue? (You can infer it from the size of the hole in the base of the skull where the hypoglossal nerve exits.) It’s bigger in us than in great apes or Homo erectus. Neanderthals are like us in this regard. But blood vessels also travel through the same holes as the nerves, and you cannot control for that, so we are not entitled to conclude that bigger holes were for bigger nerves. Worse, nerves are bundles of many nerve fibers and there are two major ways that they can get bigger: more fibers (the usual assumption, with its implication of finer control), and fibers whose diameter is greater because they have more fatty insulation. (More insulation makes them conduct faster, and also lowers the metabolic costs.)
The other line of evidence comes from the size of the nerves controlling breathing. Same results: Neanderthals are enlarged much like we are, but poor Homo erectus back at 1.6 million years ago had to get along with ape-sized nerves. Same caveats, too. Still, larger nerves do indeed suggest finer control of the chest muscles, and that is something that you would expect to improve with the careful modulation of breathing needed for speech – or for that matter, swimming, sustained running, and blowing at embers to keep the fire going.
None of this proves that Neanderthals indeed had our vocalization capabilities. Both lines of nerve size evidence, taken together, suggest that finer control of tongue and chest movements developed sometime between 1.6 million years ago and about 400,000 years ago when we shared a common ancestor with the Neanderthals – and that is at least consistent with a lot more vocalization.
Staging emerges as the central feature that says something about the mental capabilities of the hominids of this period. You have to be able to “see” a standard series of blades within the core, something like imagining sliced bread and shaping the loaf accordingly.
But, like staged food preparation, it is a routine sort of staging, passed on to an apprentice. It takes time to get good at it, just as young chimps take six years to get good at nut cracking. This sort of staging is not necessarily a new set of stages each time, the way a short-order cook can juggle an order from a whole table of people and have this unique combination all finish up at the same time.
Remember those javelins, however. That’s an advanced sort of projectile predation, and surely only some of the throws were set pieces performed in a stereotyped ambush setting. So their brains were likely busy during “get set,” trying to create a novel set of movement commands.
The issue is how much of that novel staging carried over to planning other things. If they could stage both toolmaking and food preparation, perhaps their life of the mind included other kinds of agendas as well, with more of an eye to the future. Maybe they added “ready” to the front end of “get set, go” just as accurate throwing and hammering prefaced the apelike “go” with a hominid “get set” phase.
To get ready, you have to set the stage with the right stuff, slowly get everything into position. Getting set requires orchestrating everything offline. And for ballistic actions, launching is entirely on automatic because feedback is too slow to modify the movement. So perhaps the evolutionary ordering is go-set-ready.
Morality, after all, did not enter the universe with the Big Bang and then pervade it like background radiation. It was discovered by our ancestors after billions of years of the morally indifferent process known as natural selection.
– Steven Pinker, 2002
Clearly, we are not the result of a constant and careful fine-tuning process over the millennia, and much of our history has been a matter of chance and hazard. Nature never “intended” us to occupy the position of dominance in the living world that, for whatever reasons, we find ourselves in. To a remarkable extent, we are accidental tourists as we cruise through Nature in our bizarre ways. But, of course, we are nonetheless remarkable for that. And still less are we free of responsibility.
– Ian Tattersall, 2002
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The River That
copyright ©2003 by William H. Calvin