eponymous
Actually the only thing I’m confused by is your post. The article clearly accepts that there is currently a genetical basis for distinguishing separate races. It is the idea of completely separate races that is consigned to the historical past. (The fact there has been much intermingling of the various races or groups or whatever in recent times is accepted by all). The idea that one cannot use race as a grouping from a genetic standpoint is not even mentioned.
Izzy,
The answer is very simple. It’s an encyclopedia. It is reflecting state of the art knowledge 10-15 years old. Quite simply the latest genetic data, since 1994, prove this point of view wrong.
If you are bothered by this lag, I urge you to try to pursue the original literature.
*Originally posted by IzzyR *
You’re right - I apologize. I was reading “into” the entry, rather than directly “from” the entry.
::: IzzyR - with switch in hand - leads eponymous - with foot firmly placed in mouth - to the shed outback :::
Joyce, where have you been, kiddo? Mungo Man has breathed new life back into multi-regionalism. See you in some post. As to your observation, by contemplating the sound of one hand wringing I might understand, not agree with, Tom’s philosophy.
I get it! The sound of one hand wringing!
Poor old M3! He or She can’t save MERH. There is even doubt in his/her age, have you read about this? Mipsman, change over to OOA2 and yourself a lot of grief. (And I forget how to make smilies, it has been so long.) 
Jois
Jois: How’s it going? Phil still around?
Izzy, I thought I would clarify after reading the EB article more closely:
First, Epon was correct in part that the article is using (across species) race as a synonym for population. It’s a somewhat older usage, IMHO, and its dependance on phenotype, again IMHO, dated. However, that is not inherently invalid. The Q comes in re humans: as demonstrated previously, human variation just doesn’t break down across the “classic” races – you know, white, black blah, blah. This is pretty recent information based on the results of late 1980s through 1990s advances in genetics.
The EB article states:
No objections per se here, but we have a terminology problem. And this underscores my disdain for continuing the usage of the term “race” when we mean populations. Not political correctness, accuracy: Genetic evidence, while not clear enough to precisely define the structure of our genetic history (i.e. we are still working on understanding the genetic past) clearly demonstrates none of the classic races were ever coherent populations per the allopatric race definition above, and indeed the sympatric. If the author means the classic races, then this is just hogwash. If the author means some smaller population, its possible but the author has introduced confusion.
Here, depending on what the author means, I could either say, well to an extent or plain hogwash. Again, it all depends on what “race” we are defining. And as the cites I posted clearly indicate, both genetic and physical evidence strongly point to no formal barriers ever giving rise to allopatric populations in humans, although if we had not developed culture and if we had been given another few tens of thousands of years, this could have happened…
I draw your attention to the following to help explain the issue:
Again, I would use populations because we have confusion about the meaning. (By the way, Peace/Bluish didn’t understand my hesitancy on ethnic group – ethnic group is simply a word used to describe any culturally defined identity group (say Germans or Arabs), no necessary connection with biology.)
Here the author, indirectly, alludes to the importance of individual variation being more important, in magnitude in human populations, than group variation. Nothing required this to happen, its just how our variation ended up breaking down.
And here we see an issue with the classic race grouping – the variation in frequency by group, although group-wise, does not map unto races, in the classic sense.
Also blood groups frequency, as I have read, are very subject to selection pressures, so basing ‘relatedness’ on them is going to lead you to false conclusions as relatively unrelated populations in a similar area will apparently converge on a similar group frequency.
Not a picture of coherency, no?
Now here it seems as if the author writing this is using races in both senses, that is the author is suggesting that the classic human races are in fact genetic populations. This is wrong. As metioned, the evidence clearly shows this. I assume that the article’s text probably dates in part from the 1970s and 1980s – simply its out of date.
Otherwise known as MREH: Wrong, just didn’t break down like that. While remaining muddy, the genetic evidence is clear that no such coherent macro breakdown occured. My cites posted previously adequately explain the situation.
Despite Mispman’s distortions and grasping at straws, MREH is torpedoed and sinking rapidly under the weight of the clear genetic evidence. The major backer, Wolpoff is presently holding a rear guard action but I mention Wolpoff and his supporters because they are serious scientists grappling with the data, unlike the loons like Coon etc. However, their critiques have yet to hold up.
[emphasis added]
This statement clearly tells me that the text is old and predates or was written at the start of the ‘genetic’ revolution in human biological studies. We know now that there are to date no private alleles, or more clearly no alleles which are not present in all “classic races” (barring a few micro-populations with extremely race mutations).
[emphasis added]
Voila, precisely what is clear now across virtually all variation.
There, I hope this makes my response clearer. I hate to waste time, but I thought that my initial response was unduly dismissive. The article is a good one all in all, and just suffers a little confusion in terminology and human information. But again these changes are recent.
Here’s an article from the NY Times that appears to confirm the assertions of Collounsbury, that the idea of a genetic basis for racial groupings is on the retreat. Some quotes:
A small qualifier:
And one slightly puzzling statement:
I’m a bit unclear about this. Does this mean that there is variation between “one population, or race, from another”, but that it’s less than the variation between the members of the race itself? If so, that means that the “no races exist” is only valid when discussing the science of genetics, but there can be differences (in the averages) after all.
Hi Collounsbury! Phil is alive and well and as subtle and kind in his posts as he ever was. Since he has sandblasted every not-to-his-liking topic that comes up in the old forum he has been posting more often in a different less public forum. I’ve tried to save every post he has written in either forum and will inject samples into SDMB if it’s ever appropriate.
Now I can see that I will have to go back and copy all of your posts as well!
Jois
Foist:
Jois, where’s Phil hanging out now? Always enjoyed reading his acerbic posting --and I get shit here for being less-than-warm-and-cuddly. But my posts hardly merit saving, I’m a hack, a mere hanger on. Phil is the shit, although one does wish he put some more time into brushing up his English skills.
Izzy!? I need confirmation from the NYTIMES??!?!?! I mean Genome or something like that but the New York Times? Come on man.
Fair enough. I’ll put it this way, it seems to me concensus is that there is hardly a chance of finding even a trivial fixed characteristic between the classical races. As we can’t exclude there really are little green men on Mars. But the data certainly looks real bad for those who assert that there are races. As he says, the burden of proof is on the racialists to disprove the ever growing evidence against their ideas.
It’s rather like the position of evolution.
Misreading:
I read this as a somewhat garbled observation that variation is greater among individuals in a group, however defined, than between populations. I know this is hard to grasp, but there it is.
Your second clause is wrong. The science of genetics is describing populations, its not in its own world for gods sake! I’ve continously noted that there is minor regional variation. No one disputes that. That’s clear in the data.
What I have provided what I believe is ample evidence for, is that this variation --and this is the conclusion of the majority of folks working in and/or following the field (thus Lander’s statement!)-- does not map unto the classic races! Got it? Sorry to be a bit rude, but I’m beginning to get a bit peeved these points are not sinking in. E.g. your presumption that somehow two Africans are going to be more alike (assuming we accept you were talkig about say two West Africans even) is false. Even regional differences don’t break out at that scale.
Now the caveat even if you select two large groups and select some trait which varies by region, there are probably going to be differences in averages between them. But that tells you jack. I think we’ve been over that before but let me try this metaphor:
You’ve got a whole bunch of different kinds of apples. They vary in color and size, as well as internal consistency. You divide them into dark and light colors. What can you conclude from an average of the darks and lights when dark or light color has no inherent connexion to other traits?
Okay?
Collounsbury,
Richard Lewontin has a new book out - The Triple Helix: Gene, Organism, and Environment.
Jared Diamond in the “Third Chimpanzee” makes an interesting argument for sexual selection over natural selection in explaining some of the differences in the physical appearances of humans. Can you provide any sources/information/links that support or refute Diamond’s argument? (re: current research in the literature - natural vs. sexual selection). Or have you already provided some of these in your previous postings?
Collounsbury
Actually you do, and I’ll tell you why. From your own perspective, you clearly know alot about genetics, and probably learn little or nothing new from articles in the Times, which are adapted for the lay intelligence. However from my perspective, and possibly that of others, the possibility exists that the entire subject is in dispute, and that you might simply be an adherent of one side. Were this the case, all your cites would simply be those that you found most credible and reputable, which would of course be those that agreed with your position (not that you would chose them for this reason, but you might have adopted the position because you found them credible). So the possibility is out there that the issue might not be as settled as you suggest. Especially in light of the fact that you say this new understanding is relatively recent - to the point that the EB is outdated. Further, you indicated that so-and-so (I forget the guy’s name Wolf-something?) is still clinging to outdated principles in the face of mounting evidence etc. - a possibly subjective judgement, that the guy himself, and his followers (if any) might well dispute.
In light of this, I think it’s important to look the sources like the EB and NY Times, which purport to represent the consensus of the establishment view in the field, and are unlikely to be adopting a particular viewpoint. (One thing I did notice BTW, is that the NYT seemed to give Rushton alot more credibility than you do - I’d gotten the impression from you that he is a crank).
Strangely enough, that’s exactly how I read it. I’m not sure what you mean by this.
Nothing. Absolutely nothing. And the same goes for humans. I’ve pointed this out before. There is no reason to think that skin color or other physical characteristics have any connection with any other traits. (As I mentioned in a previous thread, I’ve never heard anyone suggest this besides for melanin supremacists). However, the fact that Difference A can exist suggests the possibility that Difference B can also exist (due to the same type of mechanism, though not the same actual cause).
Here’s where I’m coming from with this issue. Genetics is a science, like any other. Like many disciplines, it has concepts that are useful in studying it. As an example, a person studying introductory genetics will no doubt be filled in with which concepts are useful to understanding the field - the details of which he will learn later.
Now, it would appear that the concept of race has no meaning as far as the science of genetics is concerned. To study or research this subject using race as a concept or category is pointless, and will lead to misleading results. A person’s understanding will not be enhanced if he persists in relating to genetics using race as a category.
However, it does not necessarily follow that for the layman seeking to categorize large group in very general terms, there is no value in this grouping. It is possible that this is the case, but it does not follow from the scientific aspects of it.
As an example, suppose there was a basis for certain populations of black people being faster on average, than most other groups. From the perspective of a scientist studying genetics, it would still be misleading to correlate black skin with running speed, because the increased speed has nothing to do with skin color, and in fact there are many populations of people whose skin is just as dark and who have absolutely no propensity for increased speed whatsoever. However, from the perspective of a layman wondering why most of the really fast guys are black, and not distinguishing one group of black people from another, it will be valid to say that on average black people have a genetic advantage in terms of speed even though many or most black people are from groups that have no advantage.
So too it is with traits varying between groups vs. among group members. It is a constant source of puzzlement to me that people keep bringing this up. The fact is beyond obvious, and has not been disputed by anyone, as far as I recall. It occurs to me that this might merely be something that is of more significance to a geneticist than to a lay person. That is, that because the differences between human groups are so small (as opposed to, say, the difference between different species of animals), and are dwarfed by the differences between members of the same groups, there is a reason for a geneticist to ignore race as a classification - a random guy whose intelligence is X, whose speed is Y etc. could be of any “race”, and it does not add much if anything to know that he is Black or White or Oriental. But it does not necessarily follow that these differences in averages are untrue. So what I’m trying to get clear is to what extent the new “race is meaningless” school of thought impacts the ordinary generalities that a lay person might use, and to what extent they merely represent a new and improved understanding of genetics. The use of qualifiers like “no meaningful differences” also adds to the confusion - there may be a disconnect between what is meaningful to a geneticist and what is meaningful to the layman.
This ties in with your statement earlier that “Now the caveat even if you select two large groups and select some trait which varies by region, there are probably going to be differences in averages between them. But that tells you jack.” What it tells you depends on what your interests are. Also your statement that “I’ve continuously noted that there is minor regional variation. No one disputes that. That’s clear in the data.” is true. You have consistently acknowledged this. But it is apparently not clear to many who are on your “side” in this issue.
Sorry to get you frustrated. But it’s for a good cause.
Collounsbury, I should post my favorite forum on this forum? Not likely! Fix your preference to accepting email for a while and I’ll email it to you. Jois
*Originally posted by IzzyR *
Good points, IzzyR - I see where you’re going with this. The perception is still there in the mainstream media (EB and NYTimes, for example) that the issue is still open to debate. Whereas the current consensus among those in the scientific community contend that (based on the mounting evidence and up-to-date-current research in genetics) the debate is basically over (or, if not quite over, then shifting the burden of proof onto the detractors). From your points and the sources you’ve provided, you’re right, there is a disconnect between what may be meaningful to the geneticist and what may be meaningful to the layperson.
Your points raises a host of interesting questions, delving into the philosophy and sociology of science. To list a few: How do findings in science filter outward throughout society (the processes involved, media used, diffusion across time and space, etc.)? What’s the time lag between acceptence of scientific research/discoveries and how that acceptance alters/shapes peoples’ perceptions? Or whether it alters their perceptions at all? Who or what determines whether a debate in the scientific community has been settled (and at what level of consensus) or if it is still open? And what is science’s or scientists’ responsibility in overturning/changing people’s perceptions in these matters (re: race is not a meaningful concept) and, for that matter, the responsibilty of the society as a whole?
Just to add an example, and perhaps a bit more clarity (to my second point). A person who knows nothing about gravity might think that it is a unique concept of objects falling “down”. Physics teaches us that every two objects have a gravitational pull towards each other, but the earth’s pull is more noticeable due to the larger mass etc. So it is likely that a physicist studying the concept of gravity would not conceptualize gravity as a “downward pull” - this would be misleading and inaccurate. But a lay person considering the effects of gravity on his world might be justified in considering it this way - even if he knew better. For all practical purposes, and to the extent of detail that he is willing to endure, that’s what it is. And it’s not that he will be wrong - there is a downwards pull. It’s only that it is not a concept by itself, its part of a larger phenomenon that manifests itself in this particular way in this instance.
Considering race, I am suggesting that there might be just enough truth behind the “race” concept to make certain broad generalizations have some validity, to the extent that they might be used by a lay person. And that what the scientists are saying is merely that for one focusing on studying the true underlying genetics these generalizations do not suffice, and are in fact misleading.
*Originally posted by IzzyR *
Well, Collounsbury and others might disagree, but I would have to agree with you - with some qualification. I tend to use broad generalizations myself, but I also know that making broad generalizations can be a tricky affair. My generalization, at first glance, may appear to have some validity. But examining the concept/issue in more detail, then the generalization may or may not hold up to scrutiny. But that’s just me personally. Where a problem may arise with the layperson is that he/she may make certain broad generalizations and stop there, without looking into the concept/issue more closely.
And I think this is where science can have a real impact. I agree with you that there’s “just enough truth behind the race concept to make certain broad generalizations have some validity to the extent they might be used by the lay person,” but its not the whole truth. In effect, scientists are saying “Look at the issue more closely - on the surface, your generalization has some validity, but at a deeper level your generalization just doesn’t stand up to scrutiny.”
Right. But an even more interesting question (to me, at least), is how do/does scientists/science effectively counter the layperson’s generalization? It’s not so much the layperson’s generalization in and of itself. But it’s the way in which the generalization may be used/abused in certain contexts. “Check your premises” as Ayn Rand would say (am I right, annrandlover?) 
Jois:
At yahoo. Anyone who wishes to email me should just use my username at yahoo.com.
Genetics:
Izzy
I was joking to an extant, but you’re quite right now that I think about it, in terms of getting a context for my discussions. I could be distorting the context. Easy enough to do if I was lying.
However, you should note the SDMB has a number of folks, such as Edwino, who have independatnly shown greater expertise than myself in genetics and biology. (And Tom is at least as well versed asI am and better at explaining I think.) If they disagreed or felt I was distorting, I am sure they would have jumped in. My links are to well known genetics journals, not second rate sources so they could surely whack me if I was misrepresenting. Indeed for those in the known, the cites and Xrefs are easy enough to track down.
But nonethless, don’t let me mock horror put you off. I encourage everyone to follow through rather than taking my argument at face value, that’s the purpose of cites (and I do make a serious effort to provide cites which can be accessed either on line w/o subscription or through most serious public libraries). And let me be clear, if I can follow this, anyone can. I’m not terribly clever. Hell, my work is in economic analysis and plant biotech.
On Rushton: I believe you’ve been mislead if the articles have been kind to Rushton. Leaving aside his work in psychology proper, which I believe to be unremarkable given other contexts, his “race” works are clearly shit. I’m not going to mince words here. His works are SHIT. CRAP On the level of creation “science.” IMHO newspaper accounts are kind to him bec.
(1) he writes in a style that folks not versed in the subject will find convincing
(2) newspaper writers are afraid of being accused of “political bias” or some such shit and so give a fringe idea “equal-time”. (The idiotic political correctness accusation.)
(3) American “conservative” writers/press pick up him, Jensen and the Bell Curve bec. of a false impression that somehow the non-racial data is ** against ** their politics. This, to me, is a ** foolish ** as well as reactionary ** misreading ** of the data. I think it stems from their false impression that the data stems from their false impression that the data is created by “radical egalitarians.”
Rather, I suspect that Freedom2 had the right instincts. The genetic data * might *support a ** libertarian ** reading of humanity --although I think that history makes a pure libertarian reading wrong-headed for cultural reasons and frankly I am not terribly enthusiastic about libertarian ideas in practice (i.e. merit is hard to determine in practice)— re individual merit and achievement over group analysis.
Genetics supports without fail the idea that the (human) individual is not a genetic function of a group. (I sincerely hope that the Libertarians on the board will take note of this and think about it and help vulgarize this information among conservatives. A lively cross-political vulgarization, like for evolution, is desperately needed)
Returning to Rushton, let me repeat, I know of no human geneticist or paleoanthro person who takes Rushton’s work seriously. It’s laughably wrong in all substantive areas. He is, in fact, a fringe writer. He, Jenkins and the majority of their cohorts don’t deserve the time of day. Their science is shit.* They’re holding us back. No we’re not all alike nor is every group alike, but their fucking stupid ideas don’t match the data. Since I believe rational science is the only way to improve the human condition, I’d sincerely like to flush these Neaderthals down the toilet.
Mipsman has accused me of being political. Well, this is not a Q of politics. Like I said above, the raw genetic data * may * support, in the end, Freedom2’s basic social philosophy more than my own. But even though he and I differ in social philosophy, I’ll say this: he * honestly * grapples with the data. I think that’s all we can ask with a moving target such as this is an open mind and a scientific attitude.
*: Note Jenkins publishes, according to all accounts, quite solid work on non-racial matters. Unlike Rushton, no one has accused him of falsifying data per se. Being blinded by his prejudices, yes. A fraud, no. See Templeton et al
Otherwise,
Hmm, well it all depends on what we mean by validity and what we’re talking about. If we’re talking about lay people keeping the false idea that blacks or whites share real genetic commonalities, no I don’t think this is useful. It strikes me a something like Creation Science.
If we’re just talking about non-biologically based generalizations, well that’s outside of the genetics and i have no problems.
Again, I have to know what kind of generalizations we’re talking about.
E.g. the generalizations that Blacks get Sickle Cell and Jews get Tay Sachs might hold up for a homogenous community a la North America circa 1900, but frankly its dangerously deceptive in 2001.
My position was not at all close to DITWD, if I understood him correctly. He was positing, at the start (a) group based intelligence differences (fine, clearly there) (b) based on inherent biological differences between these groups (not terribly likely, indeed unlikely, but let’s see what groups were used) © and those groups were defined as the classical races (or something similar). Bzzt. Wrong. Fails to meet the test as far as data goes. We don’t have racial groups (using the classical sense) on a genetic level.
**
[/QUOTE]
I think i see where Izzy is going, and I see his point. Superficial appearance traits is how we more or less define “race”- at least at the political level. And, these superficial triats must have genes connected to them- otherwise they same or similar characteristics would not occur in all the generations. So assuming we COULD id those minor genes- then we could posit a reasonable GUESS as to the "race’ of the person who had them- wit more of the genes making the guess mor e& more likely to be correct. BUT- it would only be a guess. Some white folks would have the genes for dark skin, some for curly hair. Some black folks would have the gene for a straight nose. So- if our hypothetical sample had ALL the genes of the minor characteristics we identify as “Black”- then we could be correct some 90% of the time- maybe. But- we would still be wrong sometimes. Thus- genetics does not recognize “race” as there is no gene, or set of genes- that belongs exclusively to any one race. So- if we had a gene sample- and we could id those minor traits- then we could say “this person very likely had these characteristics- and could likely be CONSIDERED for the purposes of ID only- black”. Or am I wrong here?
And, as to what my position was- I never posited “c”. I assumed it, as that is what I was taught some years ago. It was pointed out- that based upon recent discoveries- my assumption was very likely incorrect. IF that assumption was correct- then “a” & “b” (altho unlikely) are certainly not “impossible”. However, again- let me say I have been convinced that that assumption (altho perfectly good science some decade ago) is thought now to be incorrect, based upon advances in genetics.
After reading the material supplied by Izzy- ithink that you are overstating your case a bit. From what I can see- we have found no marker, or set of markers- that would allow us to point at that and say with certainty that this person is a member of race “X”- and every day, the chance of finding such a marker as applied to the larger groupings of race becomes more & more unlikley. But- it appears that the chance is more on the “% that a asteroid will hit the earth in the next year” area than the “% that little green men actually do live on mars”. However, since the “big five” “races” are likely groups of unrelated populations, which we have superficially grouped into "races’ based upon shared minor external differences- it is very unlikely, and getting more unlikely every day- that these artificial groupings will have any genetic coherance. Ok so far?
Now- if that marker, or group of markers is looked for in smaller & smaller groups- (and physical anthropologists were dividing the “races” into such smaller groups) then the chance it will be found grows greater & greater until it reaches 100% in very small groups. Thus, since some of the Physical Anthropologists had divided the “races” into such small groups that they could be considered “populations”- then we could likely/possibly find a “genetic meaning” to some of them. For instance- as a WAG the “Hairy Ainu” of Japan could be both a "race’ and a “population” and we could find genetic markers that could define “Ainu”. (Or- maybe not).
But- the chance we will find such a marker in the large grouping that some call the "Caucasian race’ is about on a par that my lotto numbers will be selected tomorrow. If we allow for smaller groupings- then the chance becomes more like ONE of my numbers will be selected. Or so it appears from the above articles and some other reading I have done recently.
Identifying the genes, or rather the alleles, is not the problem. Rather, the problem is that those alleles are (a) not held exclusively by any one race (b) re-emerge as dominant in populations because of environmentally determined re-convergence, not common descent patterns (aside from our human common descent.)
To whit, there is still misunderstanding the relationship between the distribution of genetic diversity and populations at the level of the classic races.
Here we are closer, but note that if we are using a comparision btw North American populations of “white” and “black” then of course we are going to have distributions which allow us to make better guesses than globally.
Alleles, the variants of genes to be more precise.
What do we mean? Do you mean if we have a precisely defined idea of which alleles on a package of genes which control the surface morphology --nose, hair texture etc., skin shading can we take a stab at how the person would be classified socially. Sure, but the issue is that doesn’t tell us very much at all about his genetic descent or overall heritage. As Tom has pointed out, he might be an Asian ‘negro’. Well for social purposes he’s black in the USA. There you go. Doesn’t tell us much beyond that. Doesn’t allow a successful inference that the subject in fact shares underlying genetic commonality with other ‘negroids’ more than me.
That is the whole point of observation. The point of biological entities is to be able to describe meaningful commonalities. Race doesn’t pass that test.
You mean the NYTIMES article? Ahem…
Yes, that is what I’ve been saying. In fact, given present knowledge, its darn nigh impossible.
Sigh. This sort of debate revolves around metaphor and not data. My point has been since the very start that the data is convincing enough at this point to allow us to exclude race as a useful tool, in ordinary language race is a disproven concept.
No, we already know that (a) individual variation vastly exceeds group level variation – this fact alone renders the race concept for biological purposes well-nigh incoherent (b) that regional level variation does not map unto the big five. The data is sufficient to make these statements without qualification.
It remains possible that some minor difference will show up as exclusive. E.g. there was a paper in 1999 claiming to find a fixed difference between African and extra-African populations. (linked in one of the threads, forget which) Teribly minor variation in non-functional DNA as I recall. It was roundly critiqued however bec. the authors (a) under-sampled Africa (seat of greatest diversity, ergo one should increase sample) and (b) neglected to sample known transition zones (Sahara, Horn of Africa for example)
However, even if this had held up, what does it tell us? Nothing. Assuming its correct, it doesn’t tell us that the group which has this marker (all extra-African populations plus probably East Africans) is coherent on any other marker or that the folks who don’t have the marker, (a majority of African groups) are coherent genetically…
What such research may tell us in the long run is something of history of distribution of populations.
Well, not even 100% but leaving that aside…
Well, here race simply means population. My objection to using race is simply that it inevitably leads to confusion with the classic race system and that population avoids this. Since our business should be clarity, we ditch race.
Oh, much worse.
Sure, isn’t that what I have been saying all along?
DITWS
No, not really. This is poorly written (look at the time of posting, CST.) I don’t really like to get involved here because this is the part of genetics I don’t deal with every day (I am training to be a molecular geneticist, not a population geneticist).
The ability to define race socially comes from the ability to recognize a few surface markers (nose shape, skin color, hair color and shape, etc.) The genetics is not as simple.
All of the traits listed above are polygenic in origin. The only way to maintain linkage of the different genes is through repetitive inbreeding. This happens with isolated populations, not with races. The genetics becomes muddied extremely quickly when we talk of “races.”
Let’s take Africa. We consider everybody descending from Africa (save the Berber regions) to be black. This includes Ethiopians, Nigerians, and Khoisan in South Africa. Let’s take these three groups which we all agree as being “black” for an example.
These populations have mingled over generations, but (especially the Khoisan) generally have remained isolated. I venture that you could not find a common group of polymorphisms between the three that reliably identifies these three populations as “black” versus other populations.
Everything that we do to try and define “black” from this point becomes limiting – we start to exclude groups as black because they don’t have the correct polymorphisms.
The problems all stem back to the definition of race. As has been addressed in this thread already, we cannot define race precisely. What is black? Three quarters black? One half black? One eighth black? One drop black?
Population genetics is a precise science based on a lot of statistics. Your feeling is that if we take a group of x polymorphisms (let’s say 32) we could define race.
For simplicity, let’s define a “black” race with all 32 polymorphisms. Will we define someone as “black” who is 31/32 black? Because then on average we will be excluding 1/32 people who are black.
So you say you only need 28/32 of the polymorphisms to be considered black. Assuming the polymorphisms are unlinked, there is still a significant probability that a 31/32 black person will only keep 28/32. Drop the 28/32 number, and you start including people who don’t define themselves as black.
This of course is simplified to a certain extent, but no matter how complicated you make it, it still breaks down under scrutiny.
Another problem arises when you want to use the genes determining skin color, facial bone structure, nose shape, eye color, hair color, etc. to determine race. The problem here arises that each of these traits are determined by a suite of genes (they are polygenic). The advantageous mutations of dark skin and wide nose have probably arisen several times during evolution (take the convergence of West Africans and Aboriginal Australians). So we are stuck with a suite of several hundred, if not thousand, genes that you want to determine polymorphism. Again, as your number of polymorphisms go up, the probability that you can find a set conserved amongst a race goes down (because of interbreeding between populations where the surface marker is similar but the genetics are distinct).
As I said above, the genetics becomes muddied. Without a clear genetic definition of race, the scientific concept of race frays. Because we can’t define race scientifically, for true scientists, we objectively deal with race as if it doesn’t exist. Isolated populations exist – we love studying them. We can separate these populations genetically. The problem is when we try to lump the isolated populations together in the definition of race, while trying to include those of varied genetic background and immense historical interbreeding into the same lump. It bears no scientific merit, IMHO.
I hope this is interpretable.