Re: The History and Geography of Human Genes (Was: "Mainstream Science on Intelligence" (WSJ, 12/13/
Tom Lathrop ()
Thu, 19 Jan 1995 01:47:46 GMT
In article <3eqi1q$s3o@ixnews3.ix.netcom.com>,
Lane Singer <lsd@ix.netcom.com> wrote:
>In <tlathropD23uEH.Mor@netcom.com> tlathrop@netcom.com (Tom Lathrop) writes:
>Tom! You've come out to play. I promise to be nice.
Well, you *were* a little more polite this time around, so I will try
to reciprocate.
[unimportant debate on the meaning of the word "comparable" deleted]
[foreshadowing of my "genetic diversity" point deleted]
>>Ok Lane, you've had your fun. Now why don't you explain what *you*
>>think Cavalli-Sforza meant when he referred to "'clusters' of
>>populations" that can be ordered in a "hierarchy" which "represents the
>>history of fissions in the expansion to the whole world of anatomically
>>modern humans". And please explain how the quote below means something
>>other than that the earliest and deepest of these "fissions" is the one
>>between "Africans and non-Africans".
I don't see any response to this. In particular I think you need to
ponder the word "hierarchy".
>>>[Lathrop]
>>>>
>>>>From _The History and Geography of Human Genes, by Luca Cavalli-Sforza,
>>>>page 154:
>>>>
>>>> All methods show a
>>>> somewhat greater difference between Africans and non-Africans
>>>> than between other human groups, and offer some information on
>>>> dates supporting the interpretation that the origin of modern
>>>> humans was in Africa, from which an expansion to the rest of
>>>> the world started about 100 kya.
>>>>
>>>>So according to Cavalli-Sforza (and others as well), the main genetic
>>>>division (fission) within the human species lies between Africans and
>>>>non-Africans.
>[Singer's paragraph deleted as unparsable]
>
>[Lathrops paragraph's about how 50 to 90K years is enough time to grow]
>[intellectual differences, but not enough time to evolve from chimps (?)]
>[also deleted]
Oh no! This was one of my two main points, announced as such at the
beginning of my post, and you deleted it without response! Can I take
it you concede? I'll restate my position.
I pointed out that, while a 15 point black/white IQ difference would be
quite significant in terms of human affairs, in terms of the difference
in intelligence between humans and our nearest cousins, the Chimpanzee,
such a difference is really rather small. 15 IQ points is around one
standard deviation, and is well within the range of normal human
variation. If we were talking about height one standard deviation
would be a few inches.
So how long would it take for a relatively minor difference such as
this to arise between two populations? I don't know for sure, but it
seems to me that any period of time measured in tens of thousands of
years would be plenty. If you disagree, then you need to give me some
estimate of how long *you* think it would take, and support it.
Otherwise you are simply not justified in claiming that the new genetic
studies show that there hasn't been enough time for such a difference
to arise.
Now please, I consider this point important, so can you address it this
time?
>>And BTW, what is this thing you have about northeast Africans? In his
>>book, Cavalli-Sforza refers repeatedly to "Africans and non-Africans".
>>The book is full of genetic trees showing the division between
>>"Africans and non-Africans" (e.g., page 79). Or are you simply trying
>>to belittle the non-African branch of Humanity by referring to it as a
>>"tiny subset" of the Africans?
>It's not a matter of belittling, it's just a fact that the orginal
>band of humans that wandered beyond the Sahara were just that: a
>subset of their brothers to the south. Is there a problem with this?
>This is how we know that the first fission occurred here. Genetic
>samples from sub-Saharan Africans show a much broader range of
>variation, because most of the original humans remained there,
>the Sahara acted as a bottleneck.
It's true that Africans as a group have higher genetic diversity than
non-Africans. We had an exchange of posts on this before. Remember my
lion example? I pointed out that a small breakaway population of lions
(or humans) might have less genetic variation than the parent
population, and still be superior in other respects, such as size and
strength (or intelligence). Raw genetic diversity is always nice, but
except when genetic diversity is *extremely* low it is a matter of
secondary importance.
And as for the northeast Africans, I'm less concerned with the precise
details of how the African/non-African split occurred than with noting
the fact that it *did* occur. No doubt northeast Africa was involved,
since it's part of the most likely migration route. I just don't
understand the emphasis you place there. The end result, at least
according to Cavalli-Sforza, was the deepest present day division in
the human race lies between Africans and non-Africans, and *that's*
what I consider important.
>You can see the same thing manifested in Amerindian/Na-Dene/Aluet
>immigrants to the new world. There is a much broader range of
>genetic variation present in the old world Asian population from
>which they (Amerind) derived, with the arctic weather and
>the Berring Straight acting as a bottleneck to subsequent Asian
>immigration.
>
>Back to African/non-African, this genetic disparity pointed
>to the fact that humans started there. Is this parsable? This
>also implies that the genetic info carried out of Africa was
>still present within sub-Saharan Africa, just as if one of my
>children emigrates to Japan, many of our family genes will still
>be manifest in the US through my other children.
But it does *not* imply that important differences did not arise in the
two populations after they were separated! Significant differences can
be the result of relatively small changes in the total gene pool,
changes which, as I argued above, had plenty of time to occur, and
which, as I argued below, probably wouldn't even show up in the sort of
crude statistical measures of genetic difference that we are talking
about here.
>[Lathrop]
>>>>This accords well with common sense (given the geography
>>>>of the world and an African origin for the human race) as well as the
>>>>observed differences in achievement between sub-Saharan Africans (North
>>>>Africans are mainly Caucasian) and the other peoples of the world.
>>Lane, turn to the first map in the map section of the book. This map
>>was used for the cover, so probably Cavalli-Sforza considers it
>>important. The map shows the entire world, and the caption reads:
>>
>> Four major ethnic regions are shown. Africans are yellow,
>> Australians red, and Caucasoids green. Mongoloids show the
>> greatest variation retaining some similarities with Europeans
>> on one side (a light brown greenish tinge in middle Siberia)
>> and with Australians on the other (a pinkish color in parts of
>> America and on the way to it. The extensive gradients due to
>> admixtures between Africans and Caucasoids in North Africa, and
>> between Caucasoids and Mongoloids in middle Asia, are clearly
>> visible.
>>
>>Apparently Cavalli-Sforza *does* think it meaningful to talk about
>>"Caucasoids" and "Mongoloids" and "Africans" (he avoids the politically
>>touchy term "Negroid"), and even "admixtures" between them, and he does
>>so all through the text of the book.
>Ah ah ah. He clearly specifies that this level of division is arbitrary
>and that they bear no more significance than any of the three
>to sixty other taxonomically possible divisions that have been drawn
>over the course of man's failed attempt to arrive at racialism.
>This is very sneaky of you to imply, Tom. If you have the book,
>why are you pulling this?
"Arbitrary" is not the same as "meaningless". It goes back to the word
"hierarchy" that I asked you to think about above, and with "splitters
and lumpers", as per the quote below. You can divide the United States
into states, or into counties, or even into private landholdings. All
of these divisions are meaningful; they simply occupy different level
in the hierarchy.
Similarly, Cavalli-Sforza considers the words "Caucasoid", "Mongoloid",
and etc. to be *meaningful*, and he uses them to describe the human
race at a high level in the classification hierarchy, a level
appropriate for summing things up on the cover of a book. If he didn't
think these words meant something, why would he use them here, and
indeed all through the book, as he does? The hierarchy certainly isn't
as clean as my example (the Unites States), but remember that it was
Cavalli-Sforza himself who used the word to describe the organization
of his population "clusters", and I ask you again, what exactly do
*you* think he meant?
>I never denied that there were flows of genetic diversity over
>different populations. But - our definition of "race", from a
>scientific perspective, bore the requirement that one population
>contain at least one genetic characteristic that was absent in all
>other populations. And this =doesn't= occur among humans, anywhere.
Hold it, hold it! Exactly *where* did you get that definition of
"race"? Given this definition there certainly are no distinct human
races, but this definition seems pretty far from what the
man-in-the-street thinks of as "race", and it seems like a pretty
useless definition in any case. Given this definition, if there *were*
two distinct races of humans or some other species, and even a slight
amount of mixing between them occurred, then instantly there would no
longer be two races! Your definition of race is far too unstable to be
interesting scientifically. Of course, I can understand why it would
be *very* interesting politically... :-)
>And, the groups that we have divided the world into were based,
>initially, upon the theory of multiple, separate evolutions for
>man, which led us to imagine a =much= greater genetic disparity
>than exists.
No, you have it backwards. The multiple, separate evolution theory was
a (failed) attempt to explain observed racial differences.
>>And yes, North Africas group with the Caucasians (as shown in the
>>*second* color map, representing Africa, and explicitly stated at the
>>beginning of section 3.4 in the text).
>Modern north Africans maybe, but not ancient north Africans. This
>map in question represents the world today, or as of 500 years ago
>(he clearly states that he attempted to sample populations that
>were extant 500 years ago in their present locale).
I don't think I believe this. Did you get this from the book, or do
you have another source?
>The whole point of this text is to examine human migrations, and
>to use genetic tools to do so. In that context, the =fissions= are
>what you're looking for, because then you can approximate how long
>one group has been split off from another, and how long they may have
>inhabited their current locale.
Yes. And it just happens the these fissions seem roughly to follow the
traditional racial classifications. Consider the two trees on page
79. Each of them has a branch labeled "Caucasoid", as does Figure
2.3.2.A on page 78. The tree on page 80, showing genetic distance, is
also interesting, and shows European and non-European Caucasoids to be
relatively close. Again, why would Cavalli-Sforza use the word
"Caucasoid" in this context if he didn't think it meant something?
I realize that Cavalli-Sforza seems at one point, on page 19, to deny
this. I am not quite sure how to interpret this, as it doesn't really
seem consistent with the rest of the book. It may just be a response
to political pressure, which I understand has been intense. Page 19 is
Cavalli-Sforza's defense against those who are trying to disrupt his
work on the grounds that such questions shouldn't even be asked, and
frankly he seems a touch slippery here. He says that "the major
stereotypes, all based on skin color, hair color and form, and facial
traits, reflect superficial differences that are not confirmed by
deeper analysis with more reliable genetic traits", and yet when he
actually gets around to identifying "clusters" of populations I see
pretty much the groups I expected to see. There are certainly some
surprises -- in particular Asia is more complicated then I would have
thought -- but the African/non-African split is repeatedly confirmed
and Caucasions show up as a group again and again.
And actually, nothing on page 19 seems really *wrong*. Differences in
appearance *are* superficial, at least taken one by one. As I discuss
below, dark skin of itself certainly does *not* imply relatedness. And
Cavalli-Sforza is absolutely right when he says that "The claims of a
genetic basis for a general superiority of one population over another
are not supported by any of our findings". The support for such claims
exists, but it comes from elsewhere. Very likely Cavalli-Sforza
himself is not a racist, and would not like to see his work put to such
use as I am putting it, but that really isn't his call. As far as I
can tell, whatever his personal convictions may be, his work *does*
support my conclusions.
[brief discussion of European ethnic groups deleted]
>[Lathrop]
>>>>So what does Cavalli-Sforza mean when he says that "the concept of race
>>>>has failed to obtain any consensus"? I think he is saying, correctly,
>>>>that the genetic divisions in the human race are too complicated to be
>>>>well represented by the old single level, three to thirty race models
>>>>proposed by anthropologists in the past.
>>>That's three to SIXTY, Tom. (HGHG, p19). He further states:
>>>"To some extent this latitude depends on the personal preference of
>>>taxonomists, who may choose to be "lumpers" or "splitters." Although
>>>THERE IS NO DOUBT THAT THERE IS ONLY ONE HUMAN SPECIES, there are
>>>clearly no objective reasons for stopping at any particular level of
>>>taxonomic splitting. In fact, the analysis we carry out in chapter 2
>>>for purposes of evolutionary study shows that the level at which we
>>>we stop our classification is COMPLETELY ARBITRARY.
>>Lane, saying that "the level at which we we stop our classification is
>>completely arbitrary" is *very* different from saying that the
>>classification itself is arbitrary. Why is it necessary for me to
>>point this out to you?
>It's not.
>
>To say that it is arbitrary whether we divide into 3 populations or
>60 or more =is= significant. Let me ask you: where would you stop
>classification, and why?
Where do you stop dividing the Unites States? States or counties?
Which is the *true* classification. Or is the choice, perhaps, a bit
*arbitrary*?
Where we stop dividing is arbitrary. The divisions themselves are not!
>>The book itself wouldn't make any sense without
>>the basic premise that such classification *is* meaningful and worth
>>doing.
>Worth doing =only= as an exercise in mapping human migratory patterns,
>so that we may understand our history better. That is worthwhile. To
>grab onto these division in order to further a racist agenda is most
>definitely =not= worth doing. Wouldn't you agree? Especially since this
>book =doesn't= support theories of racialism. If Cavalli-Sforza, after
>his in-depth examination of genes has not only failed to find cause to
>believe in racialism, but vociferously denounces it, why do you cling
>to it so strongly?
Lane, the history of human migrations is the history of how we are all
related to each other. There are certain things you can't do with it.
I can't for example, use it to directly argue that whites are smarter
than blacks. But neither am I going to allow you to use it to argue
that whites *can't* be smarter than blacks. Isn't this what we are
really arguing about?
And whether you like it or not, I am very comfortable with the
"clusters" and "fissions" that the book describes. If Cavalli-Sforza
had found that Swedes were closer to Chinese and Italians to Nigerians
than to each other, that would have disturbed me. But again and again
the genetic trees have a branch labeled "European" or "Caucasoid", and
the people represented by those branches just happen to correspond
fairly closely to the people I have always thought of as white. Take a
look at the principal-component map on page 82, and how African
populations group together in the lower right, Caucasoids (the book's
term!) in the upper right, and Mongoloids on the left. I have no
problem with this, and I especially have no problem with the section
summary on page 83, which begins:
The most important conclusion in this section is that the
greatest difference with the human species is between Africans
and non-Africans, but the inference that this was the earliest
split rests on the assumption of constant evolutionary rates,
which cannot be tested in full rigor from internal evidence
alone. We consider this problem in the section on comparisons
between genetic and archaeological data (sec. 2.5). The
clusters we have formed are relatively compact, but there are
indications for some populations that they may have received
genetic contributions from other clusters, as we see in more
detail in chapters 3-6. The fissions after the first are less
sharply defined.
Two other terms for you to ponder are "relatively compact" and "sharply
defined".
>>>"As one goes down the scale of the taxonomic hierarchy toward the
>>>lower and lower partitions, the boundaries between clusters become
>>>even less clear. The evolutionary explanation is simple. There is
>>>GREAT GENETIC VARIATION WITHIN ALL POPULATIONS, EVEN SMALL ONES.
>>>This INDIVIDUAL variation has accumulated over very long periods,
>>>because most polymorphisms observed in humans antedate the
>>>separation into continents."
>>There is an interesting point hidden in here, which I will get to
>>below. But think about this; if most human genetic variation
>>antedates human racial separation, then what does that variation tell
>>us about human racial differences? (Quick answer: *nothing*!)
The second foreshadowing of my genetic variation point passes
unremarked.
>[Lathrop]
>>>>For example, the first
>>>>division in the non-African cluster, between Europeans and North Asians
>>>>as opposed to South Asians, does not correspond cleanly to the usual
>>>>Caucasian/Mongoloid classification (or any other).
>[Singer]
>>>Even you, who actually believe in races, have to fudge.
>>
>>At least I am *trying* to acknowledge the complexity of the situation,
>>rather than using it as an excuse to throw up my hands and refuse to
>>talk about it!
>But why are you *trying* to scratch hard, fast racial divisions in
>humanity. What does it gain you? Cavilli-Sforza states that he only
>pursues a specific level of classification in order to study evolution.
>And in his studies, he has failed to turn up any support for racialism.
I am not trying to impose "hard and fast" racial divisions. I
acknowledge mixed populations, and that even before recent mixing there
was never any sharp dividing line between the races. But you, and
others, use are trying to use recent findings to argue that the idea of
race is a simply "social construct", and has no basis in reality
whatsoever. This is simply bogus, and the evidence doesn't back you
up.
>Anyway here's what Cavalli-Sforza has to say (HGHG
>>p155):
>>
>> ...Southeast Asia is poorly known and may be heterogeneous,
>> with the populations having an important genetic component in
>> common with northern Mongoloids and others with people from
>> Oceania. The heterogeneity may be in part due to ancient
>> admixtures, and the arrow of northern Mongoloids pointing south
>> in figure 2.15.1 express these considerations. There are also
>> some undeniable physical similarities between northern and
>> southern Mongoloids, leading one to wonder whether they have
>> more in common than shown by the trees of sections 2.3 and
>> 2.4.
>>
>>Interestingly, Cavalli-Sforza *does* seem to give some weight to
>>"physical similarities"!
>So? Who ever said there were no physical similarities, or differences
>for that matter.
But Cavalli-Sforza is saying here that physical similarities may imply
genetic relatedness. This is *exactly* what you have been trying to
deny!
>>Also note that figure 2.15.1 has two arrows
>>leading out of Africa, one of which goes along south and southeast Asia
>>and then down to Australia, while the other goes north through the
>>Mid-east and then splits into an arrow into Europe and one into Asia.
>>The caption is "Possible history and routes of expansion of modern
>>humans in the last 100 ky". This is the history I favor.
>Why is that Tom? By the way. It shows man present in north Africa
>100kya. Europe clearly has the value "35,000" pasted over it.
That map is Cavalli-Sforza's best guess at a large scale history of the
whole human race, and I support it because it seems to make sense, and
because it corresponds to the way the world seems to be divided. We
Caucasians are, very roughly, the people who left Africa, went north,
and then turned west. As a origin story, that's good enough for me.
BTW, I have no problem with 35kya. That's actually one of the hardest
numbers we have, since it is when Cro-Magnon man first shows up in the
European fossil record. As I argued above, 35,000 years seems like
more than enough time for the sort of racial differences we are talking
about to arise.
>[Lathrop]
>>>>But he is not
>>>>denying that there are significant genetic differences between
>>>>different human populations!
>[Singer]
>>>YES HE IS. Do you know what is the average variation between
>>>populations?
>>Well let's see. You posted something on this elsewhere, so let me go
>>get it...
>>
>> [Singer (taken from another post)]
>> Any random sample taken from peoples around the globe will turn up
>> 85% of all human genetic variation. The other 15% of variation occurs
>> according population and geography. Of that 15%, 9% variation occurs
>> *within* the given population, and 6% of variation occurs between
>> disparate populations. These are just gross averages, as any pair
>> of populations will differ in terms of genetic variation. You can
>> go ponder over your little 6% split if you want, but as I say,
>> there are more important things in life. Don't forget that much
>> of that 6% is taken up by very superficial qualities of build,
>> skin, hair that are adaptive to different climates. And mutations
>> come about as random events, some good, some not so good.
>>
>>Gee Lane, exactly how much of that 6% is taken up by hair, how much by
>>skin color, and so on? I assume you must know, otherwise you wouldn't
>>make a statement like that! :-)
>>
>>Seriously, the problem is that these numbers don't mean what you think
>>they mean. Consider a species with very little genetic diversity, such
>>as the Cheetah. If such a species were to split into two significantly
>>different races, most of the genetic variation in the species would be
>>due to race, simply because most of that variation would have to arise
>>after the split, since there was so little to begin with.
>>
>>Now consider a species with high genetic diversity, archaic H. sapiens
>>perhaps. If such a species were to split into significantly different
>>races, the diversity due to race would be layered over the massive
>>ancestral diversity, and would thus add little to it when measured
>>statistically.
>>
>>To spell it out for you, we would *expect* that when a genetically
>>diverse species splits into distinct races, that genetic diversity due
>>to race would remain small compared to overall genetic diversity. Your
>>6% is simply a ratio, and it is highly dependent on the amount of
>>diversity existing before the races split apart. It tells us little to
>>nothing about the importance of the differences between the races.
>>
>>And in any case, the genes that code for intelligence are only a very
>>small part of the total human genome. Why do you expect that these
>>genes would even show up in the sort of gross statistical measures
>>we've been talking about?
>Gee [Tom], exactly how much of [the total human genome] is taken up by
>[intelligence]? I assume you must know, otherwise you wouldn't
>make a statement like that! :-)
>:)
Oh no! This was my other big point, and you blew it off. At least you
didn't delete it (except for a few lines, which I've restored).
First your question. I *didn't* claim to know what percentage of the
human genome is directly involved in intelligence, in particular the
differences in intelligence between human individuals. I wouldn't try
to guess to a factor of 10,000. But given that the genetic difference
between humans and Chimpanzees is only 2 percent I'm fairly confident
that the number is well below anything we could observe now. If you
disagree let me know.
Now it's your turn. Do you concede that you cannot use the fact that
the majority of human genetic variation occurs within rather than
between populations to argue that there can be no important genetic
differences between populations? If you still disagree, will you go
back and show me where I was wrong?
Again, this was the second of my two big points, so I really hope you
will try to deal with it this time.
[unrelated "deal with it" exchange deleted]
>[Lathrop]
>>>>I happen to believe that black Africans and their descendants, as a
>>>>group, are less intelligent than whites or Asians. I may be right or
>>>>wrong in this, but it is certainly possible, just as it is possible
>>>>that they have, as a group, darker skin and curlier hair.
>[Singer]
>>>HGHG, p156.
>>>"Because genetic divergence was subject more to random than
>>>selective forces...show[s] only moderate, IF ANY, influence of climatic
>>>factors at the level of the NUCLEAR GENES investigated, but a greater
>>>influence on genetic factors involved in the adaptation of body
>>>build and bodily surface characteristics, which notoriously respond
>>>to climate. A DICHOTOMY IS THUS OBSERVED BETWEEN GENETIC DATA AND
>>>OBSERVATIONS BASED ON THE PHYSICAL CONSTITUTION..."
Note the ellipsis everyone; something important was omited.
>>You didn't understand this quote either (and you clipped out some of
>>the parts that made it meaningful). The point that was being made is
>>that in *Asia* (he was referring to Asia here, *not* the whole
>>world!!!) the principle gradient of the the human gene pool as a whole
>>goes from west to east, and is not much influenced by climate, but that
>>a subset of the genome which has to do with body build and such *is*
>>influenced by climate. Think about it. Mapping the gradations of the
>>entire gene pool may not tell us much about the gradations of
>>particular traits, such as body build (or intelligence!).
>I think you didn't understand it, Tom. He stresses that adaptive
>response to climate is more pronounced in terms of physical appearance
>(which you're so enamored of) but that these differences don't imply
>as much genetic variance as people like to suppose. People who are big
>on racialism.
>
>Also, the implication is that climate does not impart a great deal
>of alteration, genetically. Your buddies from alt.pol.nationlism.white
>like to point to severe climate as the "reason" they're so much smarter
>than Africans.
You have been using this quote a lot in other posts, so I'd better
address this. What Cavalli-Sfortza is saying is that "body build and
bodily surface characteristics" are not necessarily good indicators of
genetic relatedness. And he is absolutely right. I was well aware,
even in high school, that the dark skin of Africans, southern Indians,
and Australians did not imply that these people formed a group. This
is the "dichotomy" Cavalli-Sforza is talking about.
So what *does* Cavalli-Sforza consider a good indicator of
relatedness? Well, in the example you quoted from, in the part you
omited, he points out that in Asia "much of the gradient of the human
gene pool goes from west to east", that the "first principal component"
extends in this direction, and that the north-south climatic variation
in Asia has little effect on this. In measuring relatedness, it's
these "principle components" that matter, not appearence.
But Lane, an east-west genetic gradient is exactly what I expect to see
in Asia, as part of the long continuous transition from Caucasoids in
Europe to Mongoloids in east Asia. Once again, I have no problem
whatsoever with Cavalli-Sforza's conclusions. You are the one
obsessing on physical appearance, not me.
>>Again, these measures are too gross to tell us much about the subset of
>>genes that determine intelligence. All they can really tell us so far
>>is where the divisions in the human race lie. They can tell us that
>>the deepest division is the human race is between Africans and
>>non-Africans, but they can't tell us what this division means. We
>>don't as yet know how to get that information from direct examination
>>of our genes, so we have to look elsewhere (as Herrnstein and Murray
>>have done).
>>
>>BTW, the next page (HGHG p157) has some interesting things to say about
>>the "strong relationship between human genetic variation and linguistic
>>groups", and, oh look!, another of those trees that splits "All humans"
>>into "Africans" and "non-Africans"! :-)
>Don't triumph so, Tom. The implications are not what you imagine. On
>that note, I notice that although you quoted the discussion on S.E.
>Asians, you failed to mention what was written nearby about Europeans.
>Why was that?
I wanted to see if you were going to bring it up. :-)
>(p155)
>"There are two weaknesses in the present analysis, which will certainly
>require future work. One of them is the very short branch linking
>Caucasoids and, in particular, Europeans to the phylogenic tree. One
>hypothesis is that they might have originated from an admixture between
>their southwestern and northeastern neighbors, Africans and Mongoloids,
>between which Europeans are sandwiched."
You expect me to get upset about this, don't you? Sorry, but I'm
really not very fussy about exactly how Caucasians originated. As long
as you acknowledge that such a group exists, you can hypothesize all
you like about how it formed. (And this *is* just a hypothesis BTW,
mentioned in passing, and not one of the book's conclusions).
>In other words, some back-and-forth between those still resident in
>Africa and those who tens of thousands of years earlier had migrated
>to Asia resulted in Europeans. So really, Europeans are closer to
>Africans than are Asians. I believe I have read this more than once,
>but I can't remember offhand where to find the source. I'll take a
>raincheck on this, if you don't mind, especially since it seems to
>be =so= important to you.
This is discussed on page 71, where there is also some more discussion
on the climate issue, which you might find enlightening. And from
another source, the review article _DNA and Recent Human Evolution_, by
Mark Stoneking, in Evolutionary Anthropology, 1993, Vol 2, No 2.
The first studies of autosomal DNA variation in humans analyzed
gene products, such as blood groups, serum proteins, and red
cell enzymes. Studies primarily based on a small number of
blood-group loci suggested that Europeans and Africans are more
closely related than either are to Asians. However the
inclusion of more and additional types of loci disclosed a
clear separation between African and Eurasian populations.
More recently, analyses of variation at the DNA level have
confirmed that African populations separated first from
Eurasian populations and that this was followed by a more
recent split between Asian and Caucasian populations. This
primary split between African and all other populations in the
autosomal DNA data is consistent with either an African origin
of modern humans or with much greater gene flow among
non-African populations than between African and non-African
populations. In addition, a recent comparison of alleles
shared between humans and nonhuman primates has shown that
African populations retain the highest frequency of presumed
ancestral alleles, thus indicating an African origin for modern
humans.
>>I am making a fairly simple claim, which is that to the extent that we
>>can measure it the deepest genetic division in the human race appears
>>to be between Africans and non-Africans, and that further subdivisions
>>can meaningfully be made. I consider this all very suggestive, but I
>>don't feel that it *proves* anything by itself. It certainly doesn't
>>prove that there are intellectual differences between the races, it
>>merely gives us a context in which to discuss and possibly explain any
>>such differences that we may discover via other means.
>>
>>You on the other hand seem to feel that you can take our current rough
>>understanding of of the human genome and use it to prove that it
>>wouldn't even be *possible* for blacks and whites to differ in
>>important ways, because they diverged much too recently, or because
>>statistical measures of genetic difference are too small. And yet you
>>don't even attempt to establish what significant differences would look
>>like statistically, or how long it would take for then to come about.
>>You are making much greater demands on the data than I am, and the data
>>simply won't support these demands.
>>
>>Humans groups *do* differ from each other genetically, and "race" is
>>simply the word we use to talk about these differences. I remain
>>convinced that the reason anti-racists object to the concept of
>>biological race because they want to make discussion of these
>>differences impossible.
>Not at all. I would like racialists to recognize the historical
>foundations of their position, and admit that new knowledge has
>undermined those foundations. The notion that science doesn't support
>the concept of "race" is a new one that derives mostly from genetic
>analysis, but also from ongoing archaelogical efforts.
>
>I have no stake in a raceless humanity; it doesn't buy me anything.
>Racialists, on the other hand, base their self worth on proving their
>racial superiority. They have an agenda, and a selfish one at that.
>Agendas don't mix well with science. I'm intrigued by science, even
>behavioral science, because I want to know the truth, I want to understand
>everything (which I never will, I realize). When people with agendas
>start mucking with science, it makes a mockery of it.
Oh but you *do* have an agenda Lane. You want to prevent people from
saying politically incorrect things about race by defining race out of
existence. When scientists say "there is no such thing as race", they
mean that the structure of the human race is more complicated than the
older theories of race would allow. Perhaps even you mean something
like this. But when vulgar anti-racists say the same thing, they mean
that the human race has no structure at all, that aside from a few
superficial differences we are one big undifferentiated blob, that a
blond, blue-eyed Swede might be genetically closer to an African pigmy
than to his blond, blue-eyed Swedish neighbor, that it is impossible
for there to be racial differences in intelligence, because there are
no differences in anything (except appearance, and even that they would
probably deny if they thought they could get away with it (think about
"Those Eyes", Lane :-) ).
But I'm getting tired of this, so I want to ask you one final thing.
Do you remember how all this started? I said that recent genetic
studies had shown that "the deepest genetic division in the human race
lies between Africans and non-Africans", and you denied this. Will you
have the integrity now to admit you were wrong, or at least that
Cavalli-Sforza supports me on this point? Or are your politics too
rigid to allow even that?
--
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Tom Lathrop | Politics: A strife of interests masquerading
tlathrop@netcom.com | as a contest of principles. -- Ambrose Bierce
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