Ray Audette <[log in to unmask]> wrote:

> A recent analysis of DNA extracted from a single Neanderthal bone has
led
> some to speculate that they were not our direct ancestor because the
> split seems to occured much longer ago than the fossil record would
> indicate.
>
> NeanderThin comes from the gracile form of Neanderthal. In structure, a
> modern human is a slender form of Neanderthal, one having less muscle
> mass and a smaller head (and brain). Many examples of gracile forms of
> wild animals becoming our domestic animals through neoteny exist
> including the dog and the horse.

The modern human form is not simply a gracile or neotonous form of the
Neanderthal form.  We do have a smaller head and brain but realitve to
our bodysize they are larger.  The few Neanderthal juveniles whixch have
been studied have many of the features (e.g. browridges) which
distinguish hth two species (or sub-species depending on your point of
view).

> Just as the bones of Neanderthal indicate that this split occured only
> 60,000 years ago and the DNA sugests 600,000 years ago, so bones
> recognizable as dogs appear only 14,000 years ago even though DNA
suggest
> the split from wolves occured 135,000 years ago.  The similarity in
> ratios may tell us something about neoteny and the evolutionary time
> scale necesarry to achieve it through enviromental presures.

We have 100ka modern humans at Qafzeh and Skhul in Israel and also in of
similar age. Neanderthals existed from 2-300ka through to 27ka.  Therefore
we cannot place a divergence at 60ka: the late Neanderthals, including the
Neander Valley 1 specimen analysed for mtDNA must have diverged from
modern humans at a minimum of 100ka if there was any descent from
Neanderthals to modern humans and possibly before 200ka if Neanderthals
and modern humans share their most recent common ancestry in homo erectus.
Can you give a reference for the dog domestication genetics please?

> These presures may have included the earlier beginings of the ice age on
> the tropical homidid and the later warming of the earth for the
> temperate/arctic wolf.  It is only when both species underwent a
> significant amount of this process and existed in the same enviroment
> that domestication appeared.

> Regardless of the time scale involved, wolves are still considered to be
> the progenitors of dogs and I have no doubt that Neanderthals are the
> progenitors of NeanderThins.

Who then are NeanderThins?  The Neanderthals only occupied Europe and
the western part of Asia, and it is clear that if modern humans descend
from them, then modern humans derive from a number of ancient
populations around the world of which Neanderthals as the ancestors of
Europeans were but one race or sub-species.  This is the multi-regional
hypothesis of modern human origins in its extreme form.  In any more
moderate statement Neanderthals are the population of ancient hominids
least likely to have contributed to the modern gene pool, due to the
temporal overlap described above.

> The complexities of the processes involved
> are not fully understood yet to say otherwise.  Isolated popultions of
> wolves still exist despite dedicated efforts to wipe them out and the
> vastly higher population of dogs, making the premise stated by these
> scientists based on only one sample somewhat suspect.  If we could mate
> with Neanderthals and produce fertile offsprings, as wolves do with dogs
> (thus being the same species) is not answered by this experiment on only
> one sample.

The question of interbreeding will never be answered by DNA studies.
Genetic studies alone might lead one to believe that a Great Dane could
mate with a Chihuahua, but it is actually a physical impossibility.  We
will never know just what the Neanderthal softparts were like and so the
question of interbreeding will never be answered.  In thye same way if
wolves were extinct we would never know whether they could interbreed
with dogs, but we could still make the deduction that the two
populations (whether the same species or not) had a last common ancestor
at 135ka, and that the groups of ancient canids which gave rise to
wolves and dogs have been diverging from that point, even if they have
not yet reached the point of speciation.  A wolf sub-species which has
arisen in the last 135ka will not be ancestral to the domesticated dog
although it is related.  For humans the situation is similar but
different: we have a last common hominid ancestor for Neanderthals and
modern humans at 600ka, which is before the known appearance time of
both of them and thus shows that the Neanderthals were not the
ancestors of modern humans.

Andrew Millard

Reference
Stringer, C & Gamble, C "In Search of the Neanderthals" Thames & Hudson
1993

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 Dr. Andrew Millard                              [log in to unmask]
 Department of Archaeology, University of Durham,   Tel: +44 191 374 4757
 South Road, Durham. DH1 3LE. United Kingdom.       Fax: +44 191 374 3619
                      http://www.dur.ac.uk/~drk0arm/
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