Hi Peg,
That was a very interesting link (to the article by Michael Gazzaniga) -- thank you. What you are saying now makes more sense. Maybe the earlier disputes were due to misunderstandings that were caused by a poor choice of words or phrasing.
(Even in this latest post of yours, I would want to suggest a change of wording:
Peg writes:
Even if a nation of humans had no language themselves...
You mean "no
written language" -- remember, you are using the notion of (human) language to define what humans are, so there can't be any humans that "had no language themselves".)
When I read (well, skimmed) the article you just cited, I understood this sentence: "This suggests that it underwent positive selection" to mean that the particular families and clans that shared these novel traits were able to spread
very successfully. They achieved a degree of population growth that was never attained by the families/clans that lacked this genetic innovation -- indeed it's likely that the "farmers" expanded at the expense of the "hunters/gatherers", placing even more stress on the latter group, on top of their already difficult and limiting conditions.
But it's likely that the genetic advantage was of a more general nature -- it enabled more elaborate use of language (including better ways of preserving the knowledge expressed by language), but also enabled a lot more as well: better tool development, better methods of developing and assuring shelter, clothing and nutrition, better ability to anticipate and plan for future conditions; domestication of animals (especially horses) was also a huge factor. (Improved language ability would have enhanced all of these skills -- I think it could actually be difficult to view them independently.)
In any case, the key thing is that this change would have been relatively hard to notice in terms of overall physiology -- the ones with the these genetic advantages were only slightly different, physically, from other humans; there could still be interbreeding across groups, to the extent that other groups were in contact.
The ones lacking these special advantages were still pretty capable and smart -- they were well adapted to their environments, had lots of flexibility to adapt to other environments, made and used tools, and used languages that were structurally, fundamentally similar to those of the "farmers and city dwellers".
Just as all "modern humans" are still able to interbreed, their respective languages are all learnable by any human, and are all able to be codified into a written form using the same tools (letters or other symbols) or the same general strategies that have been applied to the historically literate languages.
It's not that the invention of writing by itself constitutes the arrival of a new species. Even the invention of agriculture doesn't do that. But what these inventions do is supply the inventors with much better odds for survival and population growth, and it is
that side effect of the inventions that
could lead, over a long-enough period of time, to divergent species, IF other conditions hold true for that long-enough period of time:
* two populations, one with these inventions and the other without them, continue to survive
completely independently of each other,
* while developing independently (without contact or mixture of any kind), one or both groups continue to undergo genetic shifts within different environmental conditions, leading to selections of different traits in each group over time,
* eventually, if members of the two groups were to come into contact again, they would not be able to interbreed (mixed couples would not produce offspring, or would produce sterile offspring).
Actually, this sort of divergence could have happened regardless of presence vs. absence of particular inventions: if human populations remained isolated from each other, in different environments and with different genetic trends for long enough, they could become different species. It's the same basic process that applies to all living species.
In the case of humans, this could very well have happened within... who knows how many more millennia... But the genetic divergence has been cut short by the fact that various "inventive" groups have expanded so rapidly to such a large extent that they can't help but impinge on other groups.
Today, we've reached the point where the population of literate/agricultural humans is having an impact on every other pre-literate/non-agricultural group, with the net effect (over the last few thousand years) being that the latter groups have been either annihilated or "accommodated" (absorbed, or allowed to adopt usage of the improved tool sets).
For those fortunate enough to get the latter treatment, the divergence of language certainly poses problems and difficulties, but is not an insurmountable hurdle.
BTW, I hope you'll stop referring to the Tower of Babel story as an historical event. There was no such thing. Even as a myth or fable, it makes very little sense. There is still a lot that we don't understand about the origin of human language in general, the origins of the major language families (Indo-European, Semitc, Central African, American Indian and so on), and the complexities of the differences among the major families.
But the processes that cause language change, like the processes of biological evolution, are now fairly well understood, well documented, and directly observable, in spite of being essentially gradual. There's no need to invoke sudden and mysterious hocus-pocus by a deity in order to account for the known facts.
Edited by Otto Tellick, : No reason given.
autotelic adj. (of an entity or event) having within itself the purpose of its existence or happening.