Re: [asa] Humanity and the Fall: Questions and a Survey

On Mon, May 5, 2008 at 12:17 PM, Dick Fischer <dickfischer@verizon.net>
wrote:

> Hi Rich,
>
>
>
> I think it is hard to evaluate the Mona Lisa by simply analyzing the
> pigment in the paint, although it might be one measure. DNA is certainly
> a valuable tool, but not the only tool, especially considering the
> difficulties extracting useful DNA from fossilized bone. The physical
> characteristics of Caucasians versus the other races could have come about
> by way of genetic mutation or partly from admixture.
>

The difficulties of contamination potentially overestimate the modern human
DNA. The reason why OOA is superior here is precisely because it concords
with the archeological data. MRE pushes the coalescent time to too long
ago. In order to deal with that MRE does special pleading of extra natural
selection. As I stated earlier, the evidence for natural selection is of the
purifying kind in humans which actually pushes it in the wrong direction.
The same goes for contamination because the currently calculated coalescent
time is most likely too recent because of any contamination. OOA on the
other hand gives coalescent times that is consistent with the archeological
data.

>
>
> You could measure genetic distance against geographical distance and get a
> correlation, I'm sure, but Chinese are closer genetically to Brazilian
> Indians than black Africans are to Greeks who are closer geographically, so
> ancient migration patterns come into play and are not always easily
> discerned.
>

It's NOT genetic distance. It's in-population genetic variability. The
Greeks have more genetic variabily than Chinese. And the Chinese have more
genetic variability than the Brazillians. You would expect this if a founder
comes later creating a more homogenous population which is further from
equilibrium. It takes unbelievable credulity to believe that this is due to
MRE. And in fact the migration pattern IS easily discerned out of Africa
into Eurasia and then into the Americas. The dates coming from the genetic
data match the archeological data to boot.

>
>
> I would think a comparison of skulls, and perhaps, body shapes would yield
> some clues. The only positive indicator I know of is the bump at the base
> of the skull which is unique to those of European descent (I have it) and
> could be what's left of the famous Neanderthal bun that served as a
> counterweight to their massive jaw.
>

From Pearson:

We do not actually know the genetic basis of any of the "Neanderthal"
> traits, so all of these estimates are only heuristic tools. Estimates of
> Neanderthal admixture derived from a recessive eight-locus model are
> probably unrealistically high, while those derived from the single-locus
> dominant model are probably too low. They only serve as approximate upper
> and lower boundaries for the amount of Neanderthal admixture that can be
> inferred from the fossil record. Nevertheless, from a Multiregional
> perspective, at least some, and possibly a substantial amount, of
> Neanderthal DNA was inherited by living Europeans. Thus far, however, *genetic
> analyses have failed to produce evidence of the expected genetic
> distinctiveness of Europeans that one might expect to arise from a
> detectable amount of Neanderthal heritage*. [emphasis mine]

The traits being discussed here are: a suprainiac fossa on the occipital
bone (95.7%, 2%) , a horizontal-oval mandibular foramen (52.6%, 1.4%), and a
dorsal sulcus on the axillary border of the scapula (64.7%, 0.4%). The
percentages quoted here are the percentage of Neanderthal followed by Modern
Europeans. The only way to get a good connection from Frayer's data is to
make an eight-way recessive assumption. All of this relies on a single,
overarching and generally untested assumption: that the morphological traits
provide a reliable indication of ancestry. In fact, the assumption is likely
*inaccurate* for many of the traits used to trace the origins of modern
humans. See Lieberman DE. 1995. Testing hypotheses about recent human
evolution from skulls. Curr Anthropol 36:159–197. To repeat, if these traits
really are there there should still be enough of a genetic residual but
Europeans are too similar to other populations for this to be the case. MRE
does special pleading by saying that this is due to positive natural
selection without the evidence that this actually has happened.

>
>
> Plus, there are reasonable inferences we can make from the push to
> extinction of Neanderthals after contact with *Homo sapiens* and the human
> tendency to save women and children while slaughtering the protective males.
> Why should we think it was any different then?
>

Uh, I don't know, like, evidence? It's reasonable to test for admixture as
it is possible. But there is little to no evidence that it actually
happened. This is the difference between science and speculation.

Rich Blinne
Member ASA

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Received on Mon, 5 May 2008 13:40:24 -0600