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Scientific basis of race (thread split)

  1. Jan 25, 2007 #1
    whoa for the biggest 1st post bump ever

    I've been involved in a few discussions over racism this week, so it's all new and fresh to me; well, I decided to post my thoughts here, for historical reference.

    This thread was looking for "scientifical" definition of human races that could be used in questions like which race is smarter, which is stronger, etc. However, the thread went into totally irrelevant direction, IMHO.

    Why does it matter who exactly are "black", for example, for the purposes of this thread? Why can't someone just begin with <definition>race X012 are people with skin color darker than 0.5 of whitest human skin</definition>, than make a <statement>adult people of X012 race are able to lift 20kg more than rest of people on average</statement>, and then commit purely statistical survey to confirm or disprove the statement? This looks like a perfect possibility to me.
    Last edited by a moderator: Jan 25, 2007
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  3. Jan 25, 2007 #2


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    Note: this has been split off as a new topic from a very old thread. It's a question worthy of discussion, but the original thread was not worthy of ressurrection. :smile:
  4. Jan 26, 2007 #3
    There are of course things that different ethnic groups can do better than other groups. Take some of the influence of the sun as an example. People with fair skin react differently than people with dark skin. Evolution is most likely a contribution to why humans native to Africa for several generations have different skin tone than the equivalent in northern Europe.

    People with a natural, darker skin tone is more adapted to the conditions in the sunny Africa than people with fair skin. The same reasoning goes the other way around; people with a natural, fair skin tone living in the cold north with less sunshine are adapted to the climate there as well. Vitamin D deficiency can be connected to the lack of sunlight.
  5. Jan 28, 2007 #4
    I definitely commend you on opening a logical discussion on such a volatile topic. One example of why people would not use the definition that you mentioned, would be the case where 2 siblings are near the borderline with one being slightly lighter and one being slightly darker. In this case you could have two people with exactly the same parents that would be classified as being from 2 different races. In this case, the concept of race would be self contradictory and would break down.

    Also, I find that the concept of race seems to be more psychologically and socially based than biologically based for the following reasons:

    1. There is more genetic variety between individuals of the same ethnic group than there is between the ethnic groups as a whole.

    2. People as a whole are not as rational as we would like to believe and will subconsciously associate greater importance to differences that are more easily visible (such as physical features) than to traits that are more difficult to see (such as blood type). For example, a Scandinavian with O- blood type is much safer getting a blood transfusion with O- blood from a donor who happens to be black than AB+ blood from a Scandinavian. However, I have never heard of any parents becoming upset because their son/daughter is dating someone with a different blood type. Race is only one of many examples where people assume the greater importance of the more easily visible. The entire marketing industry knows that the presentation of a piece of merchandise will often affect sales more than its utility will.

    3. In the previous case, I have personally seen many examples where people cling to their preconceptions even in the presence of compelling evidence to the contrary.
  6. Jan 28, 2007 #5


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    Don't forget that Alaskan native tribes (Eskimos) have very dark skin.
  7. Jan 29, 2007 #6
    Not so. If you stick to my definition, and nothing else besides my definition, one of two belongs to race X012, and other one does not. No contradictions here.

    If you are still able to identify people as members or non-members of ethnic group, you must also be able to define group borders. Nothing else, including magnitude of "genetic variety", matters.
    Last edited: Jan 29, 2007
  8. Jan 29, 2007 #7
    p.s. it is interesting, though, how "race" should be defined so that brothers from parents who belong to same race would always fall to that race.

    i mean, think about it. is it even possible. let's say we have found definition of two races, B and W such that offspring of BB family is always B, and offspring of WW family is always W. but then, what about WB families. even if we assume that their offspring can be correctly classified into W an B races, that means that, starting from 2nd generation, no genes from other race (which they obviously received from other race parent) will ever respawn prominently enough for offspring to be classified as a race that has these genes. can there be such a division made? quite a puzzle.
  9. Jan 29, 2007 #8
    I used the term "ethnic group" only as a tool to communicate a concept which would have been difficult to communicate otherwise. Perhaps I should have enclosed it in quotation marks.

    As an example to illustrate my point, here is the case of an only child in a WB family (my daughter). The interesting fact is that her skin complexion changes over time (as is the case with many people). So the possible questions are:

    Which skin complexion is her real skin complexion?


    Does her "race" simply fluctuate back and forth?

    It is easy for problems of definition to arise when we quantize concepts that fluctuate over a continuum. Also, in addition to activity of pigmentation, here are some other possible ways (according to your logic) to define "race":

    Blood type
    Body type (ectomorph, endomorph, or mesomorph)
    Predisposition to gain axial vs appendicular muscle mass
    finger print pattern type (whorl, loop, etc)
    Efficiency of gluconeogenesis
    Efficiency of neurotransmitter synthesis
    Ability of blood to clot
    Tolerance or intolerance to certain food types
    Natural pelvic tilt (anterior or posterior)
    Eye shape

    Although some of these traits are of little importance, some of them make melanin activity seem trivial by comparison. Regardless, selecting any one of these traits as a means to define "race" would cause many of the other traits to be distributed throughout all of the "races". Also, why is pigmentation chosen as the defining quality of "race" when there are so many possibilities?
    Does pigmentation make a recipient safer or less safe to accept an organ from a donor?
    Does it make one more or less susceptible to abnormal bending or rotation of the lumbar spine?
    Does it make one more or less susceptible to manic/depressive disorders?


    Is it simply the most easily visible?
    Last edited by a moderator: Jan 29, 2007
  10. Jan 30, 2007 #9
    Yes, exactly, but, unlike you, I do not see that as a problem. I mean, what's your point, should we choose the most difficultly visible qualities to define "race" ?

    We can compare to other concepts with similarly vague definitions. For example, being "smart". Once I've read few books and practiced some activities, I'm getting "smarter", but if someone will cut a half of my brain out, I will get "dumber". To conclude, there seem to be no obvious problem, again, with fluctuations of qualities.
  11. Jan 30, 2007 #10
    If you are studying the differences between groups when some of the members keep switching back and forth between groups, then it is likely to introduce inaccuracies and inconsistencies at the data collection point which will render subsequent conclusions to be dubious or inconclusive at best.

    I do not see any reason why your study would bother me one way or the other. However, the fact that a biological study chooses ease of perception over relevance to biological function, only further reinforces my point which is:

    The modern day concept of "race" has more basis in psychology and sociology than in biology.:smile:
  12. Jan 31, 2007 #11
    statisticians have struggled long enough to deal with this. but "my study" supposed nothing about its relevance to biology, neither has it outlined goals, etc; it was only stating a possibility.

    would you like to elaborate, what exact expectations you have for "biologically justified" concept of "race"?
  13. Jan 31, 2007 #12
    I apologize. I assumed (from the location of the thread) that it was about biology.

    That is an excellent question and a very difficult one to answer. After a reasonable amount of traveling (I stopped counting after 30 countries), I have come to consider the idea of race to be irrelevant. Thus, whenever I refer to "race" or "ethnic group", it is strictly for ease of communication.

    If someone were to formulate a biological definition of race, it would depend on what the person is looking for. Even in these cases however, the definitions could be vague and problematic. An ER doctor or nurse would probably have a greater need to classify people by blood types. An exercise physiologist or physical therapist would probably be more interested in body types, pelvic tilt, or other traits affecting biomechanical function. However, there are many possible ways to classify and many are extremely vague. You were exactly right when you said in a previous post that even the definition of being smart is vague, and I can give solid examples to support that (but that's another lengthy post).

    Although geneticists can tell someone's "race" by looking at the DNA, they can already tell many other traits and they will eventually be able to discern just about any trait. As a result, many experts in the field are starting to consider the idea of "race" to be irrelevant. With the countless ways that we can categorize people, many are starting to say that:

    You can consider humanity as one race with a population in the billions.


    You can consider humanity as billions of races with each(except for twins and other natural clones) having a population of approximately one.:smile:
    Last edited by a moderator: Jan 31, 2007
  14. Jan 31, 2007 #13
    Ah... the politics of race. I'm very sleepy right now but I'll try to cobble something together.

    This is true but misleading. Substitute genetic variety with other types of classifications like age. "There is more variety in age between individuals of the same age group than there is between age groups as a whole." That may be true but it doesn't mean age doesn't exist or that it isn't a useful tool.

    Blood types are useful too, but they're not even close in showing all the diversity in human genetics. Certain diseases and traits for example are more connected to race rather than blood type.


    According to that article there are enough clear-cut differences to have medical relevance.

    Here are some relevant passages that support race:

    I recommend reading the entire article however. Interesting stuff.
  15. Feb 1, 2007 #14


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    What's clear is that all humans belong to the same species, if we define a species as the collection of individuals that can interbreed (have natural descendants which are fertile themselves).

    However, even the exact definition of a species has its limits, as is shown by the existence of "species rings", where a single species migrated along two different paths, separated by a natural separation (water, mountains...) such that, along the two paths, although the individuals COULD in principle interbreed, they don't because of their geographical separation, and hence constitute individual evolving "gene pools". If they do this long enough, then there will be sufficient genetical drift between them, that they can't interbreed anymore. This is what happens in a species ring, where, after sufficient migration, the two branches meet again, but are now different species which don't interbreed (even though at that place, there is no geographical barrier anymore).
    Along the two branches, there is a continuous variety from the original mother species to the two new species. It is not clear at what point a new species really developed, given that there is a continuous variation. But at the end, the two populations are clearly two distinct, non-interbreeding species.

    In the same way, within a single species, one can have geographically isolated groups, which do not interbreed. Given enough time, they evolve differently and will finish as two different species. "half-way" one can call this different sub-species ; but as long as they can in principle interbreed, they belong to the same overall species.
    So probably if Africans or Native-Americans had been isolated long enough from Euro-Asian populations, they would have evolved in different species. Given that there are already different traits common to the "gene pool", we could classify them as different sub-species or races, but this is up to some point arbitrary. Given that the barriers are broken now, and that there is no more a geographical or other barrier limiting interbreeding, probably the human species will mix again and racial differences will tend to get wiped out, mixed into one big human gene pool.

    Given that not enough time has elapsed for the isolated human populations in Africa or in America to evolve into different species and that the barriers are broken again, it is probably not even useful to consider sub-species (which would be proto-species, in the course of evolutionary separation), as they will never devellop into genuinly different species.
  16. Feb 1, 2007 #15
    Thanks phusicist. That was a rather informative article.

    Also, thanks vanesch. What you said makes sense.:smile:
  17. Feb 2, 2007 #16


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