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Author | Topic: Human Races | |||||||||||||||||||||||||||||||
NosyNed Member Posts: 9004 From: Canada Joined: |
I will confess to having given up following this thread awhile ago. However I thought a small article in the "American Scientist" might be interesting to the participants.
This is from the Nov-Dec 2003 Issue:"Black" and "White" Not Quite Right It is a study of the genetics of Brazilians who are a mix of Portuguese and Africans. They grouped individuals into 'black', 'white' or 'intermediate' based on skin color. Some excerpts:"In samples from both urban centers and rural districts, the distribution of African alleles was the same for the "black" and "intermediate" Brazilians: Both groups' average AA1 values fell between the European and African ends of the spectrum. and "The white Brazilians also showed a high proportion of African allelic markers, although the distribution was not as pronounced as in the black and intermediate groups. The reason for this became apparent when the identity of the markers was considered---the OCA2 gene, part of the test battery, encodes a protein that regulates pigment production, meaning that the marker itself contributed to the phenotype. When this site was excluded from the AA1 calculation, there were no significant differences in the African genomic ancestry of black and white study participants." Since I think we started off with a general idea of race, which to most people is associated with skin color other characteristics, I think this helps point out that race doesn't even guarentee a correlation with color. ------------------Common sense isn't
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Too Tired Inactive Member |
quote: We'll certainly have to talk differently about race if the degree of racial admixture found in Brazil ever becomes the norm in the rest of the world. Thanks for bringing the Scientific American issue on race to our attention. John
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Peter Member (Idle past 1506 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
quote: So, if you exclude all the bits that make us differentwe are the same ... Black and white is too broad, but the above says that thedifference has to be specifically excluded. If there is significant inter-breeding for a number of generations why expect there to be clear distinctions left. This is not the global norm. Added by edit (so as not to do another post): Won't Portuguse have 'African' ancestry even inportugal too? Certainly in the southern parts, where the Moors held sway for some considerable time ... doesn't that history conflate matters? There is also mention of 'African allellic markers', andof Brazilian people falling between the European and African AA1 values. Doesn't that mean that there are races, otherwise one could notspeak of allelic markers. [This message has been edited by Peter, 12-15-2003] [This message has been edited by Peter, 12-15-2003]
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Peter Member (Idle past 1506 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
quote: That's more or less what I HAVE been saying.
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Dr Jack Member Posts: 3514 From: Immigrant in the land of Deutsch Joined: Member Rating: 8.3 |
Haven't read most of the thread; probably won't. Just thought I'd mention, since it is perhaps relevant to what has been discussed.
There's a good article in the latest Scientific American about this; those interested might want to read it.
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NosyNed Member Posts: 9004 From: Canada Joined: |
We'll certainly have to talk differently about race if the degree of racial admixture found in Brazil ever becomes the norm in the rest of the world. Perhaps the result is already there. I've seen one picture of "africans" that shows a very wide range of skin color. Maybe we started off with a limited connection between skin color and genetic makeup. The separation since then has allowed for more separation of the genetics. It all comes down to showing that the common or original idea of "race" doesn't mean what we thought it did. ------------------Common sense isn't
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Too Tired Inactive Member |
quote: In any case, racial admixture in Brazil is much more advanced than in the US.Parra et al. 2003 in PNAS Just a moment... estimated the proportion of African admixture in rural "whites," "intermediates" and "blacks" as 31-32%, 45-48% and 51-52% respectively. An earlier article by Parra et al. in AJHG, p1839 here:http://www.journals.uchicago.edu/...rnal/contents/v63n6.html sampled 9 major US cities and found an average of about 17% European admixture in blacks (i.e., ~83% African ancestry) and only about 1% African admixture in whites in a sample of three cities. I don't have any handy references but it's a reasonable guess that admixture of the major races is negligible or nearly so in much of East Asia, Europe and sub-Saharan Africa. John
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Peter Member (Idle past 1506 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
Thanks, I'll take a look.
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Mammuthus Member (Idle past 6503 days) Posts: 3085 From: Munich, Germany Joined: |
quote: This is almost like a creationist argument. Rather than answer the question, you claim the burden is on me because it contradicts your opinion. Your working definition of subspecies which you equate with "race" is idiosyncratic and can hardly be equated with a common view of "race". But since neither you nor Peter seem willing to state what this commonly accepted definition of race among the billions of humans on the planet that rubes such as sfs and myself seem to have missed there does not seem to be much point in continuing.
quote: Base on what? Why not species then? Or genus? Since the defnintions you have proposed and what you have written in your faq are so arbitrary one could give a single base change in cytochrome b between two individuals any taxanomic value one wishes.
quote: This is rather vague...what "race" is Colin Powell? Actually, my mother is spanish. My father American. On my mother's side there is moorish influence. My father is a mixture of Russian jew, German jew, and non-descript Welsh. What major "race" group am I...according to you I should instantly be able to identify my race in such a way that everyone else does...which sub-species am I?
quote: I would say it makes quite a bit of difference since you are claiming it as a precise biological concept that everyone should accept blindly and without question yet at the same time admit it is so arbitrary that anyone can define the concept as they choose...how useful is that?
quote: Ah yes, good debating tactic...claim that the opposition is ignorant and has yet to recognize your brilliance. Fine, you find the consensus agreement on what species are among evolutionary biologists...I am sure you will define it as whatever you think it is...however, in reality species as a concept is also highly controversial and debated...and it does matter for a variety of reasons including how conservation efforts are focused...this thread shows race is an order of magnitude worse...Feel free to ignore it or dismiss it with another vague statement. [This message has been edited by Mammuthus, 12-17-2003]
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Peter Member (Idle past 1506 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
quote: I thought I had ... I suggest that commonly held view on raceultimately correlate to geographical ancestry. I've just read the Scientific American article mentioned too,and there are results there that found that Alu's can be used to make genetic groupings that correspond precisely with conintent of origin. With 60 Alus one can get a high correlation, using 100 Alusone can get 'almost 100%' correlation. The experiment correctly grouped Sub-saharan africans, Europenasand East Asians by genetic means alone. It is also reported that investigations have concluded thatAfrican-Americans have 20-100% West-African origins ... so there's your answer about dealing with inter-breeding .. i.e. you can still find the markers.
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Mammuthus Member (Idle past 6503 days) Posts: 3085 From: Munich, Germany Joined: |
quote: This does not deal with interbreeding...if you have 20% West African, you have 80% something else...what "race" are you? Then you switch within the post from clear sub-saharan African to West African. Many of these "interbred" people have themselves had children who are even more mixed in ancestry i.e. from people of different geographical origin. If you have alleles that are a mix from multiple different populations, you will not be able to identify the "race" of the individual. Within geographical groups the mixing will form a normal distribution with those living in proximity more closely related...so which alleles do you pick as "sub-saharan"? I did not mean to completely lump you together with Too Tired as your reasons for not having defined "race" are different. I think you yourself are not entirely sure where to draw the line. Too Tired thinks that race is self evident, that billions of people agree with anything he says, that quoting Steve O'Brien is evidence, and that anyone who disagrees is stupid. I do not consider your arguments or reasoning to be equivalent...just that niether of you has given a clear definition of what "race" means.
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Peter Member (Idle past 1506 days) Posts: 2161 From: Cambridgeshire, UK. Joined: |
quote: The switch is just in reference to the SA article. That's whatthe author there reports. The fact that they can say that someone is 20% West Africansuggests that the level of inter-breeding is interpretable up to a point. Apparently it is harder to differentiate between populations fromthe Indian continent, due to extreme inter/out-breeding. I agree, logically, that with sufficient levels of inter-breedingthen racial distinctions will disappear. I don't believe this to be a global norm at this stage, however. The succesful identification of 'racial' group from geneticgrouping suggests a biological basis for race ... but I concede that that is one based upon a 'geographic origin' interpretation of race. I believe that this is ultimately where all racial distinctions are founded.
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Too Tired Inactive Member |
Mammathus writes:
quote: No, the burden is on you because the division of humanity into geographical races has been recognized for hundreds of years.
quote: How so? Please elaborate.
quote: Since you've compared the common view of race to the subspecies definition and found them to differ, you imply that you can define this common view of race for us. Why don't you go ahead and give it to us, since Peter and I can't seem to please you with our sorry attempts? Just look it up in the dictionary if that helps. I am really quite curious to know how you define 'race' such that human populations don't qualify.
quote: Based on what I understand to be a reasonable definition of the term race or subspecies. I wouldn't consider sub-Saharan Africans to be a different species because they don't meet the criteria of the biological species concept, which I take to be the most common species concept among biologists at the present. Why do you want to argue this with me? Why don't you argue it with someone who believes in different human species? Or are you really incapable of drawing distinctions between these taxonomic categories?
quote: Your reading comprehension leaves something to be desired, but in terms of the major races I'd say you're Caucasian.
quote: Again your reading comprehension seems lacking. Please identify in which post or posts I claimed any of these things.
quote: My favorite debating tactic is to keep the issue as simple as possible. My point in this debate can be summarized as follows: the differences between major human populations (those we commonly refer to as major 'races') are not substantively different from the differences between the subspecies of other mammal species. Therefore, to claim that human races don't exist requires that we define race to be more like 'species' than 'subspecies' (which in my opinion is hard to justify.) Now, you can alternatively argue that we shouldn't refer to human populations as races because the concept of race (or subspecies) has too many shortcomings, but that's distinct from arguing that human groups aren't races because they wouldn't qualify as subspecies. I don't think I've come across anyone yet who agrees that if humans were any other species they would have subspecies, and yet argues for abandoning the term race due to its looseness. John
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Too Tired Inactive Member |
Mammuthus writes:
quote: Admixture is a simple concept. If races didn't mix when they meet, they wouldn't be different races, they'd be different species. To claim that admixture somehow nullifies the reality of different races is to ignore what it really tells us, which is that the parent groups are indeed conspecific.
quote: In many contexts race IS self-evident. It certainly was evident long before population genetics came along since it doesn't take any special training or ability to recognize consistent differences in hair form, hair color, skin color, facial traits, etc. between different geographical groups. As for these other silly claims, show me where I've said any of them. If you're so ill-equipped to argue your case that you have to resort to this sort of thing, maybe you should give it up until you've had a chance to educate yourself. John
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Mammuthus Member (Idle past 6503 days) Posts: 3085 From: Munich, Germany Joined: |
This conversation is becoming highly uninteresting as you are both consistently condescending and evasive. Hopefully this will change..if not, no loss for me either.
quote: Please then elaborate on what you understand to be a "reasonable" definition of the term race. I have asked you several times. Summarize your faq because even there it is not clear. I would not say the biological species concept is necessarily the most common and given it is itself hotly debated, I doubt you could form a consensus among scientists. So yes, I am incapable of drawing subspecies, species, race distinctions because I have seen EVERY one of those terms used interchangebly by you, by Peter, and in the scientific and lay literature.
quote: I don't see how you make the logical leap that if one does not accept "race" (however one defines it) one must instantly jump to a higher taxanomic division. In fact, almost everyone except for you and Peter has argued exactly the opposite. While there may be variation that correlates with geography, the level of admixture among human populations suggests exactly the opposite of growing differentiation among groups but of homogenization.
quote: Now this is the most interesting part of your post. The looseness of race is an issue. It is more variably defined than species or even sub-specis. I have not seen even here a consistent formulation of the concept either on the pro or con side. If a drug developer wishes to test a new product in clinical trials, is claiming that sub-saharans form a distinct group a true biological guide to the efficacy of the drugs? Does a loose concept of race help in any way? If the geographical distance does not correlate with the genetics of a group due to historical migration , invasion and other sources of admixture, then what? Though it is at some level a semantics issue, using historical terms that have multiple connotations is does not simplify biological study for those of us who are actually in the field.
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