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Race: the Scotsman and the Yenta

  1. Aug 9, 2004 #1

    marcus

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    Race seems to be an important factor in human biology and medicine these days, not to mention sociology, so I want to explore the idea with one or two thought experiments. Anyone interested can help correct or clarify.

    in Jewish culture of a century ago, we are told, there was a community figure called the Yenta who made sure that a nice Jewish boy married a nice Jewish girl. The desire for endogamy (mating within the group) can be symbolized by this semi-mythical woman the Yenta

    in an analogous way there are Scotsmen who are passionate about protecting the breed of Border Collies and find any unregulated exogamy unacceptable.
    In rare cases I suppose exceptions can be made in order to breed some particular excellence into the line.

    It occurred to me today that genetic engineering offers a very strange possibility----namely of modifying the number of chromosomes so as to produce an offshoot species. that is to create fertilized ova, for implantation in volunteers, which mature into individuals who look exactly like the rest of us and have the same difficulty remembering where they put the car keys but who cannot produce fertile offspring except within their own group.

    this prospect might have appealed to many a frustrated Yenta because the nice children would have quite limited choices beyond the approved----exogamy would preclude grandchildren.

    the same opportunity seems to present itself to the Dog Breed enthusiast.
    If they really care all that much about the desired characteristics "breeding true" and keeping the pedigree straight and all that, well they can go and genetically modify their Border Collies and create a new species.

    At this point you could tell me that the human version of this had already been the subject of someone's admonitory SciFi story called "The Yenta Gene". In which some people split their breeding population off, and isolate their gene pool, from some other people---and eventually, perhaps because the larger population becomes resentful, or perhaps because SciFi writers like to show the horrible consequences of our ideas, tragedy ensues.
    That is the idea of admonitory stories, the moral is "dont try it look what will happen!". It is so pat it could have happened on Star Trek.

    anyway, with your permission I want to think about these things, what is race what is species what is cultural pseudo species what is culture
    why is the human race so polytypical (when you think about it it is is really a crazy racial quilt----but there are many kinds of beautiful women in the world including a Japanese lady I know and I always thank the nonexistent god of evolution for this. and so there is compensation for all the suffering we, by our nature, endure.
     
    Last edited: Aug 9, 2004
  2. jcsd
  3. Aug 10, 2004 #2
    Interesting idea. One thing is for sure genetic engineering is on its way for better or for worse. Personally I think the prospect is awesome. I don’t think we can survive without changing ourselves. We seem to have far too many traits that serve our genes and not the greater interest of the world, which of course makes sense. But I think it will be the end of us unless we are able to change. No question the prospect is also scary and potentially dangerous; nearly everything in the hands of humanity seems to be.

    How to define race and species? We can’t even define what life is, or what a planet is. So with that in mind, I leave it to someone else :)

    Why are we so polytypical? That all comes down to natural selection. Differences in our physical environment as well as our cultural environment are going to result in different traits being selected for. So different populations of people are going to over time evolve differently. Clearly this is what has happened. And if a trait is selected strongly enough for or against it wouldn’t take very long for its genetic effect to become noticeable.
     
  4. Aug 10, 2004 #3

    marcus

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    what you say sounds really sensible to me
    BTW thanks for responding!
    it seemed like such a strange idea that I was a bit afraid
    of being shunned for voicing it
     
    Last edited: Aug 10, 2004
  5. Aug 10, 2004 #4

    Monique

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    Let me respond with the following scenario:

    A spaceship is build and is launched with a number of people on board, the spaceship goes on an intergalactic journey.. a major consideration with a trip that would take centuries is, that eventually you'll get inbreeding and that will lead to genetic instability.
     
  6. Aug 10, 2004 #5
    Isn't Earth a space ship? :)
     
  7. Aug 10, 2004 #6

    Monique

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    There are inbred populations on earth that promote genetic counseling before a couple marries.
     
  8. Aug 10, 2004 #7

    marcus

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    Hi Monique, I am not sure what you are trying to tell us!
    It is part of our folklore that too much inbreeding is bad.
    (leads to the expression of lethal recessives, mental deficiency, and a hundred other bad things which geneticists give us lectures about :smile:)

    but what is your point? you seem to be suggesting something here
    which I dont grasp.

    to take examples let us consider some populations------Japanese, Swedes, Finns, say

    I think they are comparatively inbred especially maybe the people of Finland because disasters from time to time reduce the population and then it builds back up from relatively small gene pool.

    or some island Polynesians for example.

    I may be naive but it seems to me it is not so tough to be a finn or japanese or swede.

    Also I am hopeful (again as a very unexpert lay person) that genetic science may in time alleviate whatever ills these small genepool people may be suffering.

    So what I am suggesting is that anyone who advises maximum outbreeding in all cases and who is telling these people to get rid of whatever is distinctive about themselves----well that seems too simple. It might be just the wrong prescription for those particular Finns or Japanese.

    It could be a good prescription for some Polynesians. I really dont know. but I suspect that maximum outbreeding is no panacea! There may be more selective ways of dealing with lethal recessives and all that.
     
    Last edited: Aug 10, 2004
  9. Aug 10, 2004 #8

    marcus

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    BTW years ago I used to cruise in sailboats and we would visit islands.
    I remember visiting an island in the Chesapeake with a few hundred families where for some reason everyone seemed to be named Jones.
    Only the local physician, as far as i could tell, had a different name.
    Boy how these people had intermarried!
    they did not seem all that much the worse for it though. the boys immediately came out to the boat and swarmed all over, polite but curious.
     
  10. Aug 10, 2004 #9

    Monique

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    You suggested to limit the ability of people to breed between groups, I'm saying that only breeding within a certain group will be deleterious.

    Ashkenazi jews is where the genetic counseling was taking place. The Finnish or Japanese populations are not inbred, maybe sub-populations of them are.

    Did anyone see the movie GATACA? Is this really where we want to go?
     
  11. Aug 10, 2004 #10

    Nereid

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    In-breeding for small populations of Homo sap. is perfectly fine ... as long as we are prepared to accept the evolutionary consequences. No doubt that many a Pacific island was populated by humans who subsequently didn't make it (I doubt that we'll ever know how many hundreds of cases there were). In recorded European history, we have the sad tale of Vikings in Greenland ... if there were no native Greenlanders, and if the colony had been cut off from Europe (so only in-breeding of the small founder group were possible), what are the chances they'd have come to grief, at least partly because of the in-breeding?

    marcus, you might like to do some numbers on gene flow ... start with two quite distinct groups (genetically), allow exogamy, at a constant x% ... after how many generations has the distinction between the groups been essentially rendered invisible? Now compare that with the timescale over which significant evolutionary change happens, to a mammal like Homo sap. Finally, pick any group of humans in today's world (they don't have to be distinct from any other) ... can you find one that has an exogamy rate below 1%? What trends are evident over the last ~500 years?
     
  12. Aug 10, 2004 #11

    marcus

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    It is interesting you say Finn population is not inbred. What is the technical meaning of "inbred"
    You see I dont know a lot of technical distinctions. To me the human species is to some extent inbred because they dont mate outside. It is a question of degree.

    Are you saying that if a population is endogamous then if it is, say, above 10 million people in size, then this is not inbreeding? For me endogamy means inbreeding. But to speak techically correctly, as you do, endogamy only equals inbreeding if the genepool is below a certain size?
     
  13. Aug 10, 2004 #12

    Monique

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    It is not as inbred as people once thought, for a review on the molecular genetics of the Finnish population, read the following free review article by Peltonen et al published in Human Molecular Genetics http://www.ncbi.nlm.nih.gov/entrez/...ve&db=pubmed&dopt=Abstract&list_uids=10469845

    There are different levels of inbreeding, in the Finnish population it might have taken place at random when people were moving inland and thus settled new villages and isolated themselves. If you look at the recessive diseases, you see that they occur in hotspots. The population as a whole has sub-isolates that would be inbred.

    You are right, endogamy does not necessarily mean inbreeding: it depends on the population size, population dynamics, and also on the time-span over which it is occuring.
     
  14. Aug 10, 2004 #13

    Nereid

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    That's pretty much the definition of a (sexually reproducing) species! If individuals of one group cannot produce viable offspring by mating with those of another, then you have two species (some exceptions?). Speciation happens when, for example, two groups become isolated (= no breeding between the groups), so each group evolves independently (in the sense of no breeding between groups) to the point where cross-breeding becomes impossible (or produces offspring incapable of reproducing).

    It's a little trickier with plants; (cross-species) hybridisation is both possible and in many cases common.
     
  15. Aug 10, 2004 #14

    marcus

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    Good! It seems to me, as an amateur, that the effect of population size is highly non-linear.
    One can, i would guess, actually calculate a safe population size based on things like mutation rate and prevalence of harmful recessives.

    Let us imagine that a safe level is 10 million Finns.
    We imagine that a village of 100 or 1000 might have problems but suppose 10 million is OK. And one must stir the soup so it doesnt burn. The young people have to move around outside the villages in order to get the benefit of this fine big 10-million-Finn genepool.

    So let us proceed with the thought experiment. Remember I am certainly not advocating this I simply want to think it through philosophically, so to speak.

    Now, a wizard appears one day with 10 million green pills.
    He says to the Finns, they should all take these pills and they will
    then be chromosomally incompatible with the Russians, Lithuanians, and Swedes, their neighbors. One of the lovely Finn girls breaks into sobs
    because she happens to be in love with a Latvian boy but they tell her it's all right she doesnt have to take the green pill if she doesnt want.

    So then each of the other Finns gets a glass of water and they prepare to take their pills. These pills will make them into a Finn species.

    Damn, unfortunately I have to go to the produce market to get vegetables!
    The avocados are best in the morning and it is getting late. Will have to continue later
     
  16. Aug 10, 2004 #15

    russ_watters

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    If inbreeding can damage a group of say, 100 people in only a handful of generations, can predictions be made about larger populations, ie with a million people it would take on average a thousand generations for a large number of genetic defects? How well has this relationship been studied?

    For example (please don't turn this into a racism thread), sickle cell is somewhat racially linked: could increasing interracial marriage eventually reduce the occurrences of it?
     
  17. Aug 10, 2004 #16
    Eugenics has allowed the Ashkenazi jews to have by far the highest average IQ on the planet. Im sure that when outbreeding occurs (as it certainly is doing in the US) it lowers the average IQ although the offspring are not Ashkenazi jews.

    Gataca is innacurate because most people (even the non genetically modified) are white. By then, most people will probably look close to what the african americans do now. Except that instead of 20% white genes, it will be 80% african heritage and the other 20% being mostly arabic and indian.
     
  18. Aug 10, 2004 #17

    Monique

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    Maybe the Ashkenazi jews have an above average IQ, I don't know, but they are also plagued by genetic disorders that are being passed down among their people. You win some you lose some, unless you carefully plan everything out like in Gataca.

    On your second paragraph: that does not relate to this discussion.
     
  19. Aug 10, 2004 #18

    Nereid

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    for russ and marcus (principally): my personal take is that we can't possibly know! First, most babies live to puberty, most teenage girls are fertile, and most teenage boys are not sterile - my guess would be that 'most' in all cases is >90% (oh, and immortality for women would make close to zero difference; most women live to menopause). I'd be astonished if there were another mammal species with this level of potential. Further, changes in the social organisation of Homo sap are happening at a rate many many times faster than even the most in-bred group's genes would change.

    Russ: yes (kinda); it's a bit like a topic of discussion among Finns (so I'm told) - when will the last blue-eyed, blond-haired Finn be born?
     
  20. Aug 10, 2004 #19

    Monique

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    One could study a population that was founded by a handfull of people.. one I know of are the Sanguenay Lac-Saint-Jean, in new france in Quebec. In 1700 there were 20,000 people that explosively increased to 80,000 in 1780. It was common until 1920 to have 20 children per family. Interestingly this population was founded by far more men than females (6883 vs 600). Although consanguious relations do not occur, you would expect a level of inbreeding. There are some typical genetic disorder that occur, maybe iansmith knows more about the population.

    I don't think it will be easy to predict because the genetics depends on genetic drift: you don't know which genes are going to play a significant role. Especially with a very large population you have too many variables to model.

    Even with a single copy of the gene do people become sick, only less severly. It makes sense that if you breed outside of a risk population, that the chances of obtaining two copies will decrease.
     
  21. Aug 10, 2004 #20
    The typical negative effects of inbreeding become appearant with *very* small populations. As recently as about 80 years ago, people here in the rural parts of Europe lived in isolated villages or "extended communities" comprising a small number of villages of maybe a few hundred people and married each other over dozens of generations with little exchange with the outside world. Now *that* is a situation where you get a certain likelihood of genetic disorders - there were *far* more "village idiots" in these days than there are today. Not marrying first cousins etc was a way to minimize damage.

    Of course, you don't see that kind of impact on a population's health when the endogamous population in question is a nation of 120 million like Japan...
     
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