Thursday, January 19, 2012

Migration 11: Wilson and the Standard View (revised)

In building up my picture of pre-Neolithic Homo sapiens, I am dependent on finding a variety of scientists, experts, commentators, who have written about the relevant issues at a level I can comprehend and engage with. I certainly have done no original research, unlike my writing based on Grand Canyon archival work. This requires a rather different sort of respect, which is easy to show for the work of Edward O. Wilson, who combines immense authority for his research, e.g. on ants and superorganisms, while commanding attention for his writings, e.g. on sociobiology, in which he ranges far in the subject of human nature. Which happens to be the title of his book (On Human Nature, 1978, Harvard) I am currently wrestling with.

I see twined themes on which we both proceed: 1. From (page) 19: "The question of interest is no longer whether human social behavior is genetically determined, it is to what extent." 
2. The answers to that question are, 96, deeply relevant and crucially important in the most important current issues of humanity and its future.

What makes Wilson's book so useful for me is that he presents something like a standard model of what scientists picture when they describe human development in the pre-Neolithic, pre-historical age from, say, 100 millennia ago. What surprises me is what is not emphasized in his writing, especially the role of language. Such a lack seems to me an error, whereas other aspects, such as his emphasis on male dominance, are perhaps more a matter of perspective and choice of model. I am also troubled by his ignoring our migratory character, but that may very well be due to the discoveries of the past 20 years underpinning the out-of-Africa hypothesis championed by C. Stringer, whose latest book -- not yet available -- deals with questions about and modifications of that hypothesis. 

Wilson's comment, on 20 (of  On Human Nature) is certainly widely shared: "Social behavior can be evaluated … by comparison with the behavior of other species and … by studies of variation among and within human populations." He sees the "picture of genetic determinism emerg(ing) most sharply when we compare selected major categories of animals". And, of course that means "the great apes and monkeys", "our closest living evolutionary relatives". Immediately obvious to me here is that such evaluations skip language. He lists, 20-1, four shared traits of pre-Neolithic humans with apes and monkeys:
1. Groupings of 10-100 adults. I am OK with that size of human bands.
2. Males are larger than females, although humans not so much, so "the predicted average number of females per successful male" is two; "we are a mildly polygynous species". This is a major difference with my view of more egalitarian arrangements among human mutually supportive bands.
3. There is a long period of social training -- that seems fine --, first by "closest associations with the mother", then with other children. But apes & monkeys do not migrate and they do not have language. A migratory language-using creature that requires years of education and upbringing in a world full of danger would surely be more evolutionarily successful if that upbringing were carried out as a group responsibility. If, for example, a mother dies during the baby's first year, would a child be abandoned? So "social training" is a major point to explore.
4. Social play features "role practice, mock aggression, sex practice, and exploration". What about the development of language? And for pre-Neolithics, was"mock aggression play" to show how to smash & bash, or an education on control of such behavior?

Wilson's turning to the chimpanzee to make other comparisons is a common trope, although the split in our lineages took place millions of years ago (mya). When Wilson wrote, it was 20 mya, what he called an evolutionarily short period. Now, Wikipedia sources say, it has shrunk to  5-7 mya. Yet language may be as recent as 200,000 ya or less. Wilson wants to show closeness by describing how humans have made chimps get some language. But he does not mention that even with 6 million years, chimps do not do such stuff on their own, nor teach their children or friends speech when we force them to learn it. He presses on, trying to find similarities, so he can claim, 31, "we have a little-brother species".

Then, 31, there is the huge chimp-human genetic overlap. The gross number, come up with much more recently, is 1-2% difference, but the details are devilish: Here is a 2005 abstract from Nature: Nature 437, 69-87 (1 September 2005) | doi:10.1038/nature04072; Received 21 March 2005; Accepted 20 July 2005
Initial sequence of the chimpanzee genome and comparison with the human genome  The Chimpanzee Sequencing and Analysis Consortium25
Here we present a draft genome sequence of the common chimpanzee (Pan troglodytes). Through comparison with the human genome, we have generated a largely complete catalogue of the genetic differences that have accumulated since the human and chimpanzee species diverged from our common ancestor, constituting approximately thirty-five million single-nucleotide changes, five million insertion/deletion events, and various chromosomal rearrangements. We use this catalogue to explore the magnitude and regional variation of mutational forces shaping these two genomes, and the strength of positive and negative selection acting on their genes. In particular, we find that the patterns of evolution in human and chimpanzee protein-coding genes are highly correlated and dominated by the fixation of neutral and slightly deleterious alleles. We also use the chimpanzee genome as an outgroup to investigate human population genetics and identify signatures of selective sweeps in recent human evolution.
And another Wikipedia-sourced comment:
And while we’re discussing the genetic similarities of humans and apes, here’s a well-kept secret: we don’t share 98.8% of our genes in common with chimpanzees. What we share, for sure, is about that much similarity in our overall nucleotide sequence for the regions of DNA we share in common. Why is this distinction important? First, a single gene may be 400 nucleotides in length, but a change in just one of those nucleotides (far less than 1%!) can code for a different gene. Second, there are upwards of 700 genes in humans that are not found in chimpanzees. Third, there are nearly 5 million “indels” in each species (regions of the DNA that have been inserted or deleted). And fourth, there are major differences in the rate and timing at which genes we do share in common are turned on and off during growth and development.
Anyway, Wilson next reverses his view and gives primacy to chimps, wanting us to be chimp-like alpha-male-dominated creatures. It is worthwhile asking why chimps are such favorites. Wilson does not distinguish bonobos as models (Chris Stringer and Steven Pinker are more explicit in their rejection), with their female-centered social organization. However, bonobos and chimps are closer to each other genetically and developmentally than either are to us, and still came up with social organizations based on opposite gender assignments. 

So it is relevant to ask, if these really, really close cousins can be so differently organized, why do we, not quite so close, have to be like either? Surely, our social organization, based as it is on language, could be as markedly different from any apes. as bonobos are from chimps. Moreover, even if a few million years ago we started out like something else, did not the genetic changes since the split provide us with opportunities and challenges that even way back then, showed up as changes in social organization? Then toss in, most importantly, the development of language. It may be fairly "recent", but surely it promoted, even evolutionarily selected for, a social organization to take advantage of its benefits. Benefits that seem to me would be maximized when they involve social, extended, open, back-&-forth. Language needed a group setting to develop, surely. Dictatorship and dominance do not promote speech and its benefits now, why should they have 100 millennia ago? Do we have to fantasize about an Arab Spring way back then, with old-fashion inarticulate alpha males toppled by the new medium of fluent language use? Could not earlier developments like being upright, having fire, eating cooked food, etc., have been producing a society in which language was nurtured by and reciprocally nurtured openness, discussion, narrative, speech-based learning?

So why do scientists like to cuddle up to chimps? Are we were so  lonely that we need an extended cousinage? My own sense is that in understanding humans and how we lived 100 millennia ago, we are on our own, and ought to leave chimps in peace, instead of torturing them into Lamarckian behaviors. I would also suggest that when we look back into our prehistoric past, we need to be very careful of the distortions brought by looking through the lens of the tremendous changes wrought by the Neolithic Revolution. 

Chimps aside, Wilson wants, 34, to restrict cultural evolution to the post-Neolithic, which I think is a serious limitation, given our pre-Neolithic accomplishments of spread and culture (think of  boating to Australia 60 millennia ago and 30-millennia-old cave painting). Strangely, he then jumps way ahead to talk about Israeli kibbutzim to show the incest taboo as genetic. Another genetic-based trait, he says, is hypergamy, women marrying up. Since this has no place in the pre-Neolithic, he uses civilizations in China & India to clinch his argument. This, again, seems to be a practice that writers on humanity's development/history fall into: They compound their arguments from a mix of pre- and post-Neolithic, almost ignoring or down-grading the truly revolutionary impact of the invention of domestication. It does get confusing. For instance, Wilson argues, 80, we do not diverge culturally too far from what our biology allows. His politically correct example: Slavery goes through cycles in our history, and always self-destructs. Slavery is a culture-based relation fighting biology because of competition with free labor (US) and our desire to be in group relations. Reproduction declines, and violence is more & more required. 

So much for slavery. Consider the (unrelated?) comment another skeptic makes about sex on the DNA files website:
There does not seem to be enough gene-stuff for behavior or sexual behavior to be the exclusive expression of the genes in humans or apes. Terry Deacon says it well: “Genes are under the control of epigenetics. Epigenetics are under the control of social behavior. Social behavior is under the control of culture.” Variations in sexual behavior are cultural, just as the notion of deviance is cultural.
Wilson instead argues by analogy with other vertebrates again; he says healthy males mate more; weaker may not mate at all maybe. But all females do. So if times are tough, then more daughters, because males die more, and genetics selects for daughters.  A Wikipedia analysis of lineage for mitochondrial Eve and Y-chromosome Adam show Eve back to 140-290 millennia, and Adam only 70, a sign that Y's have a higher extinction rate (in chidbirth, perhaps?). This could be support for the idea that successful males are differentially way more successful at having many, many children. However, if sexual activity were more widespread, it could be that weaker males just produce children more likely not to make it. And what about females going after a succession of males attractive to them? We, influenced by 10 millennia of the importance of heedless, headlong male activity may be uncomfortable with the idea of assertive females, but that does not mean our pre-Neolithic ancestors found mutuality and universal consensual behavior odd, particularly since it would have enhanced their chances for evolutionary success. That is, if sexual behavior is socially controlled in a concealed-ovulation, mutually supportive environment, wouldnt we have been better off with a set-up with all members acting on their attractions and trying to have sex, rather than the alpha-male centered view, more suited to an estrus-displaying animal? 

We need, I guess I am saying, to take the plunge and accept our uniqueness. For centuries, we have been trumpeting the triumphs (science vs. the church?) of discoveries that have moved us and our world from being the rational lords, cynosure and center of all the universe, to peripheral, inconsequential, limited things. I would prefer that we accept those discoveries along with the sense of how unique (so far) they make us. Can we develop the strengths language provides us, and celebrate them?

--end of first part--

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