Monogenesis and "simple Darwinian grounds"

[Miguel Carrasquer Vidal]

----------------------------Original message----------------------------
Johanna Nichols <johanna at uclink.berkeley.edu> wrote:
 
>This has nothing to do with selection, but note that estimates of the size
>of the earliest modern human population (ca. 100,000 years ago) range from
>a few tens of thousands to a million or more.  The range within which
>modern humans evolved, and within which homo erectus evolved, and so on was
>comparable in dimensions and shape to New Guinea, and the ecological
>context was riverine and lacustrine tropical.  Under comparable ecological
>conditions, modern languages of the least complex societies show tremendous
>diversity of language families and languages, as well as small
>speech-community sizes for languages (a few hundred individuals per
>language in many cases).
 
This whole subject is of course plagued with uncertainties and
assumptions.  I tend to like Eldredge/Gould's theory of "punctuated
equilibrium", which states that speciation generally takes place in
small isolated populations.  I also tend to think that the origin of
"language as we know it" and the origin of our species are related
events, which would indeed take us back to Africa some 100,000 years
ago.  As to population size and area, my guess would be probably less
than a million and somewhat smaller than New Guinea, but somewhere in
that general range.
 
What I don't know is if it's valid to compare the situation in New
Guinea now (or rather, before the colonial era) to the situation in
Africa then.  The linguistic situation in New Guinea is the result of
many thousands of years of human settlement and, presumably,
linguistic differentiation (with little in the way of external
influences outside of the litoral areas where Austronesian languages
are spoken).  The situation at the time of language origin/human
speciation [IF we can equate the two] has no linguistic history, by
definition.
 
>This makes it hard for me to believe that there was ever just one language.
>There might well be a secondary kind of monogenesis in that all but one
>line has gone extinct
 
That idea has always appealed to me.  For one thing, it allows us not
worry about whether homo erectus or h. neanderthaliensis had language.
If they had, those languages are extinct and only the branch(es)
spoken by the earliest h.s.[s.] can survive.  Another situation which
might (but certainly need not) lead to monogenesis of this secondary
kind is the question of early human dispersal.  Even assuming that the
human "homeland" supported several (unrelated?) languages, it may well
be that only one group migrated out, their language becoming the
ancestral language of all varieties spoken outside of a little corner
of Africa.  A small reflux movement would then provide "instant
monogenesis".
 
But let me state again the many uncertainties.  We don't know exactly
how human speciation took place.  We don't know if language predates,
postdates or coincides with the speciation event.  Even assuming a
small isolated "original" population, possessing language, we don't
know how small the original population and area were exactly, making
it hard to say whether a single or multiple dialects/languages may
have been in existence.  We don't know how humans spread out from
their original habitat.  We don't know if secondary extinctions may
have led to "monogenesis of the second kind" at a (much) later date.
 
The odds are that all human languages share a common origin, if not by
primary, then by secondary monogenesis, but there's no way to know for
sure.
 
=======================
Miguel Carrasquer Vidal
mcv at wxs.nl
Amsterdam