-Submitted by David Drumm (Nal), Guest Blogger
Leading scientists, including evolutionary biologists, geneticists, and anthropologists, can’t agree on the existence of human races, and it’s a fascinating discussion. The human desire to categorize everything is often puzzling, sometimes amusing, and sometimes enlightening. Race is one of the results of our categorization compulsion applied to ourselves.
To define race, Jerry Coyne turns to our experience with animals: “races of animals (also called “subspecies” or “ecotypes”) are morphologically distinguishable populations that live in allopatry (i.e. are geographically separated).” While humans from Norway and from sub-Saharan Africa are certainly “morphologically distinguishable,” for example in skin pigment, eye and hair color, and nose shape, there is a continuous distribution on morphology between the geographic extremes.
As can be seen from the graph above, from Human Races: A Genetic and Evolutionary Perspective (pdf) by Alan R. Templeton, genetic distance and geographical distance form a cline and not discrete changes that would indicate races. It is possible to cherry-pick the genetic information from geographically distance populations and produce a graph that clusters those populations and claim it manifests discrete races. However, this ignores the in-between genetic information that smears the discrete clustering into a homogeneous mix.
Templeton concludes:
Hence, human races do not exist under the traditional concept of a subspecies as being a geographically circumscribed population showing sharp genetic differentiation. A more modem definition of race is that of a distinct evolutionary lineage within a species. The genetic evidence strongly rejects the existence of distinct evolutionary lineages within humans.
From Genetics, Evolution, and Man, L.L. Cavalli-Sforza wrote:
The criteria for the definition of races – based on geographic distribution and various features of the body – yield classifications similar to those obtained using genetic markers. Use of genetic markers also shows very clearly that there are no “pure” races. Races are, in fact, generally very far from pure and, as a result, any classification of races is arbitrary, imperfect, and difficult. Yet anyone can see that there are certain relatively clear differences between a typical Caucasoid and a typical Mongoloid or a typical Negroid.
In the landmark paper The apportionment of human diversity, R. C. Lewontin found that 85% of all human genetic variation is found between individuals within a nation or tribe and only 6% between the races. Since obvious phenotypical differences exist between human populations, that 6% variation can have significant effects. Not all genetic variation is created equal.
H/T: Nick Matzke, Jerry Coyne, Larry Moran, Jonathan Marks, Jan Sapp, Razib Khan, Todd R. Disotell, Jason Antrosio, A.W.F. Edwards (pdf), Guido Barbujani and Vincenza Colonna(pdf).
lotta,
hey, i thought this was a medblog. Sorry for my stupidity.
Always looking for folks on my hobby kicks. Back to the civics class and Legal Rudimentals for Dummies 101.
Any other non-law nerds here besides Dredd and Tony?
idealist, I can’t help at all, I have no training. I started reading about the ‘virtue’ of sickle-cell anemia a bit ago but aside from understanding the bottom line I can’t explain the mechanics. Sorry.
Lotta,
Looked at the link on malaria. Question remaining for me is if the carbon monoxide protects against lesion formation, BUT the life cycle of the plasmodium is not effected. So the plasmodium may increase in number in the host? What stops that process? Is the host always a carrier then if infected once??.
Can you help me there.
Thanks for the link, BTW. Most interesting to find protection in the form of counteracting effects, not the organism or its infection modes. That was new to me.
Really worthwhile post; Nal.
Where do you shop,ideas, you mentioned there were several places?
Any idea how much is career-jockeying and/or fund seeking behind the ideas compared to to real scientific conviction or essential value in the ideas?
Lastly, permit an opinion on categorization in general.
How much of categorization is driven by the need for finding shared characteristics so as to establish a nameable group. This reduction of quantities to be handled by our limited brain capacity, is achieved by grouping. This then serves as an aid in theorizing, synthesizing higher level concepts, and perhaps greater insight.
The point being, as you have shown, that categorization can be problematic, in many ways. Even, as you show, the category can be elusiive in its definition. And pursuing them can lead to lots of work, but little fruit, other than ones accruing to those who pursue.
That it leads to concepts which are misused socially is unfortunate.
Women as a category leading to unfortunated societal results is another such category. Do rights relate to gender? Some think so.
Or are they related to personhood.
I support the latter.
Great post, Nal.
Some people are really bothered by the idea, that race is an artificial concept often used to stereotype people. Those people are known as racists.
Another great posting Nal, thanks.
What differences do occur seem to be related to localized environmental factors (maintaining core temp./adding immunity for malaria etc.) and aren’t relevant to cultural expectations. Even if my neighbor to the immediate north was a sub-Saharan African with sickle-cell and my neighbor to the immediate south was a First Australian and could maintain a higher core temp. in the cold while sleeping, those traits have nothing to do with anything relevant to the society or localized culture we live in.
Aside from some medical uses the meaning of race is, for practical purposes, without any existential meaning. That to me is what is meant by the use of the word “predictive” and to that idea I subscribe completely.
http://www.sciencedaily.com/releases/2011/04/110428123931.htm
Nal,
Well kiddo, when you can get the 5 grandkids in the 18-24 year old age group off the topic of skiing and on to the topic of “Scientists On Race” for more than a half an hour during the family’s Sunday dinner, you have moved a couple of mountains!
Blouise,
Thanks. The evolutionary blogosphere has been very active this past week with posts about race, all starting with Jerry Coyne’s post. The differences of opinion are somewhat artificial, like any race classification.
Nal,
I know I mentioned this earlier, up thread, but thank you so much for following up on that link you posted last week with this column.
The entire thread has been a joy to read from beginning, well … to whenever it ends.
Trying to make pigeon holes on a continuum often leads to trouble
“Forked man speak with white tongue.” (Dredd) … lol … stealing that one too.
Tony C said:
So what? You will not find any race or subgroup where the population is completely homozygous for any trait. However, the higher rate is indeed important. Please remember that this was the phrase that I objected to:
Obviously, race IS predictive of certain things, and a few of them are important in an evolutionary sense because they lead to a reduction in reproductive success.
FYI
http://www.nytimes.com/2012/03/04/world/middleeast/bearing-witness-in-syria-a-war-reporters-last-days.html?pagewanted=1&_r=1&ref=world
Re Anthony Shaddad’s last journey, by his photographer collegue, Tyler Hicks.
Roger Lambert 1, March 4, 2012 at 12:51 pm
“race is no longer predictive of anything”
I don’t think that is true.
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Forked man speak with white tongue.