Re: What are race promoters promoting?
Susan S. Chin (susansf@netcom.com)
Sun, 24 Nov 1996 23:10:21 GMT
Susan wrote:
: >My understanding is that races are geographical variants of a species.
: >The morphological differences between populations become greater the
: >farther apart these populations are.
gkeyes6988@aol.com wrote:
: This understanding runs into a lot of problems. Ituri pygmies, Bantu,
: !Kung Bushmen and so on all share geographic proximity and are all
: considered part of the "Black" race in the "3 race" typology you put
: forth, but they are divided by profound phenotypic differences. What they
: have in common is a dark skin pigment and residence on the continent of
: Africa.
Precisely. The 3 African groups you mention, all share dark skin pigment
as a result of their origin and evolution in the African continent. They
differ phenotypically likely due to local adaptations to various
environmental differences in their original habitat(s). I'm not familiar
with exactly what these habitats were, but it would surprise me if the 3
phenotypically differing groups share identical evolutionary histories
and habitats. They may be in geographic proximity today, but were they
always this way?
: >The similarities between populations
: >are due to similiar adaptations to environmental demands.
: Since humans use culture to do the bulk of their adapting, actual
: adaptational differences are few (like the sickle cell trait). Most other
: so-called adaptations to climate are the result of phenotypic plasticity
: or non-adaptive factors like gene drift and the founder affect.
If humans used culture to do the bulk of their adapting, at
what point did this begin? When we became anatomically modern Homo
sapiens, we stopped evolving biologically? Obviously the human lineage
has evolved biologically through time, why would you expect this to stop
at Homo sapiens? Or at the level of "races"?
: >This racial
: >differentiation occurred once early hominids spread beyond Africa and the
: >Old World.
: This is certainly one view of human origins -- that Homo erectus evolved
: seperately into H. sapiens in different places. This theory has a number
: of problems. One is that DNA comparison suggests a much closer
: relationship than that. Another is that this scenario (various H. erectus
: species evolving in isolation) would more likely lead to actual
: speciation. If this had happened, the "races" would not be able to
: interbreed at all. Finally, the assumption that H. erectus was somehow
: "driven" to involve into H. sapiens wherever they were implies a sort of
: directional evolution which few biologists credit these days.
I made a very general statement in saying "early hominids spread beyond
Africa and the Old World." Are you disputing the idea that the human
lineage began in Africa, and spread from there? Early hominids does not
imply Homo sapiens!
: > Limited interbreeding between populations lead to these
: >phenotypic differences which we can easily recognize as a "racial type,"
: First of all, I think you must mean genotypic, for if all differences are
: phenotypic, there would certainly be no races. There is unquestionably
: genotypic variation within and between human groups -- it just doesn't
: break sort into easily identifiable "racial" groups unless skin color is
: your single criterion.
No, I meant phenotypic. The definition of phenotype used here is "the
observable expression of the genotype." Phenotypes are *based* on
genotypes, how else would these observable characteristics come about?
Culture is definitely not the answer. Phenotypes are the expression of the
interactions between the environment and an individual's underlying
genotype. What produces phenotypical differences is the different
way the environment affects the expression of the underlying genes (thru
evolutionary time). This is commonly known as adaptations.
: Another view (from the one you propose above) is that there has been
: considerable gene flow throughout human history, and that humanity
: represents a continuum of physical variation which we arbitrarily divide
: into artificially discreet races.
Races don't exist because not everyone fits into a discrete category, it
therefore is arbitrary? If that's the case, then colors don't exist either
because they're in a continuum as well (and here I mean colors in
general, not skin color). Racial groups exist. Individual races, that's a
much messier proposition.
: >physical anthropologists recognize 3 major groups.
: The vast majority of Physical Anthropologists do not recognize this and
: have not for many decades.
A current citation please.
: > Subsequent migrations
: >have obviously blurred the lines of what criteria should be used or can
: >be used to differentiate the "races." But if looked at from the point of
: >view of geographic origins, most humans today can trace their heritage
: >back to one or more likely, several geographically distinct areas.
: Again, this is an assertion which has never been demonstrated and which
: much data (like skeletal analysis and DNA analysis) suggests is untrue.
Again, a current citation please.
: It is one paradigm of many, and to survive it must be supported by better
: evidence than alternative paradigms.
What are the alternate paradigms?
: >Recognizing that races exist as a phenotypic category,
: Again, you certainly mean genotypic here.
No, I meant phenotype.
: >one that doesn't
: >always place individual humans neatly into clear categories either
: >phenotypically or genetically, doesn't negate the fact that the
: >differences we observe between people today are due to the geographic
: >origins of their ancestors.
: Again, this is one of many views and must be supported. Archaeological
: and Paleoanthropological data bear out that there were once other SPECIES
: of humanity, but there is no clear evidence that human variation used to
: be greater than it is now, as you suggest. Again, analysis of DNA
: suggests a closer genetic unity the farther back you go -- though I
: readily admit that DNA analysis has some problems.
Just looking around at modern human populations will tell you geographic
racial groups do exist, if only on a phenotypic level since it has
been problematic finding "genetic" criteria to group modern human variation.
: > Differences aside, we are more alike than we
: >are different. We're all members of one race, that of the human variety.
: I agree.
Glad we found something to agree on :)
Susan
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susansf@netcom.com
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