At 14:11 2000-02-02 PST, you wrote:
>
>John wrote:
>>Glen, I can sympathise with your frustration, but believe it to be
>>short-sighted. All I ask is that you similarly aquaint yourself with >a
>>rudimentary understanding of modern genetic theory, instead of >rashly and
>>misleadingly accusing me constantly of racism. I am >probably better
>>equipped to understand modern theories of human so->called races than you
>>are so please disist with these attacks on my >credibility on these
>>matters.
>
>I cannot and will not oblige. I'm not ignorant at all on the topic of
>genetics. I use the term racism in its most simplistic sense: "the belief in
>distinct human races". The concept of distinct human races is flawed in
>every sense of the word because genes are too fluid amongst our species to
>classify people based on them. It would be like classifying people based on
>the color of tie they wear. Moronic.
Perhaps I shouldn't mix in this, however Glen, it is really You who is
moronic when You claim there are no human subspecies (races).
I'm an ornithologist myself and to me a race simply means a morphologically
distinct geographical subpopulation of a species, with absolutely no
political or ethical implications. In this sense Homo sapiens (like most
other animal species) is quite definitely divided into several races and I
personally can't understand how anyone can deny anything so obvious. And,
yes I know that a number of biologists who really knows better claims that
it is not so, but this is just the victory of political correctness over
reality. As a matter of fact it is perfectly easy (for me at least) to
determine the subspecies and approximate geographic origin of most humans
in the field. The fact that there are hybrids which are difficult to
classify and that there are areas with intermediate populations is of no
significance, and is indeed only to be expected since subspecies aren't
reproductively isolated.
I am perfectly aware that the human species is remarkably homogenous from a
genetical point of view, probably mostly because we are an extremely young
species (200-300,000 years?). The biologically interesting question is how
(and why) such a young species has become so strikingly polymorphic in such
a short time, for not only are humans divided into races but these races
are remarkably different in appearance, more so as a matter of fact, than
for most polymorphic species.
In fact it is quite common for reproductively isolated species (e.g. Common
Redpoll and Arctic Redpoll, to take a somewhat extreme example) to be much
less distinct physically than are e. g. Australians of european and
aboriginal extraction. In this particular case there are even significant
osteological differences which is rather unusual for subspecies (of some
300 Swedish bird species, I can only think of one where You can determine
the subspecies from the skeleton).
Note that this does not imply great genetic differences - the number of
genes involved is certainly not large. The odd thing is that there is such
striking differences for those rather few genes that code for traits that
show up in physical appearance.
In part these differences are certainly adaptation to physical conditions,
many of the traits characteristic for australian aborigines being for
example obvious adaptations for life in in a hot, arid environment with
strong sunshine, but I am fairly sure that this is not the whole story.
There is strong genetic evidence that the human species has passed through
at least one fairly narrow population bottleneck in the past. If this
involved several small isolated populations some differences may simply be
due to random genetic drift. A perhaps more likely explanation is sexual
selection, since this is known to able to cause striking differences in
physical appearance between very closely related taxa, such as Birds of
Paradise or Ducks.
Finally I can't see what is wrong with using subspecific differences to
reconstruct patterns of migration. This is done all the time in zoology.
Nobody accuses me of racism if I claim that the Yellow Wagtails with yellow
heads that have started to breed in southwestern Norway in the last few
decades originally immigrated from Great Britain since they clearly belong
to the (british) flavissima subspecies, indeed everybody regards this as
self-evident. Certainly thorough genetic analyses are better, but they are
also much more difficult to perform, and the data is usually just not
available.
Tommy Tyrberg