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Incest. Does it really produce retards?

  1. Dec 29, 2004 #1
    I cant remember what i was told but in science class the teacher just said that incest just enforced the weaknesses in your genes such as color blindness.

    Also, I was watching this documentry once of how egyptian phaoros often had children from incest and as a resultant they had deformations like abnormally large hips and as a result of there deformations didnt live as long.
  2. jcsd
  3. Dec 30, 2004 #2
    "retards"??? Let me guess you were going for the politically correct look.

    Incest increases the chance of rare recessive traits showing up. For example, if a man has an allele of a rare genetic disorder, which is a recessive than it is very unlikely for that person to mate with a another person who also has the recessive allele. So most likely the trait will never show up. But, if the same man mates with his sister, there is a very good likelyhood that she too will have the recessive allele - so most likely their offspring will inherit the 2 recessive alleles, which will cause the trait to be manefested.

    An example of this is lab retrievers. They are breed very pure, but b/c of this the is a rare hip disorder that is displayed in an unusually large number of dogs.

  4. Dec 30, 2004 #3


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    Since I am a person who has been genetically diagnosed as colorblind (I do not have the gene for green cones, therefore I am a deuteromorph, the most common type) I guess it falls upon me top defend our so-called "weakness".

    Despite my inability to sometimes correctly match certain items of clothing (my wife is very handy for this), I hardly find this a detriment to my life and I would also point out some of the known advantages of colorblindness. Our ability to ignore certain shades allows us to better define edge/outline characteristics and makes us less likely to be fooled by camouflage. This attribute was and probably still is utilized by military forces who prize the colorblind sniper. Also our night vision is typically better than the average person, I believe due to the shift in rod/cone numbers. Thus these advantages probably dictate the prevalence of colorblindness in our society (~8-10% of males) as it carried a fitness advantage to our hunter-gatherer ancestors.
  5. Dec 30, 2004 #4
    We also call this inbreeding depression, where inbreeding causes the decrease in overall fitness of a trait.
  6. Dec 31, 2004 #5
    I seem to recall reading somewhere that most mutations were recessive in nature. Is that true? And if so, why?
  7. Jan 2, 2005 #6
    thanks for your info on color blindness. but id still rather see a rainbow with all its colors.
  8. Jan 2, 2005 #7


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    well, if you were raised as not seeing any different, it might not make any difference. the term color blind is such a limited term. there are many "colors" we cannot detect, so by your definition, you are colorblind, unless you can see ultraviolet light. :rolleyes:

    and i suggest you do a little more research on what a retard is, as the context of how you used it in this topic is quite degrading to a group of people who enhance lives in ways you might not expect.
  9. Jan 2, 2005 #8
    What is the politically correct term? metally challenged. I thought that was scientific term.
  10. Jan 3, 2005 #9


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    While it is true that terms like cretin, idiot, moron and mentally retarded originate from medical and judiciary circles, such labels are rarely used today, even in science, and are typically associated with offensive and/or derogatory statements. Generally when referring to individuals who live with such conditions the exact syndrome, disease, etc is used, i.e., Down's syndrome, Asperger's..., rather than lumping vastly differing levels of functioning, even within a single disease-type, into some convenient class.

    Definition's for mentally retarded status are easily found on the web or one can check the latest Diagnostic and Statistical Manual of Mental Disorders (DSM) at most libraries. You will probably find that most of the definitions are associated with law and judiciary procedures. These remain because changing laws that are on the books is a particularly complicated task.

    The term "colorblind" is rather misleading as Kerrie states. I can see all primary colors and enjoy a rainbow as much as the next person. Where it comes into play is in shading between colors. Thus on a graded color scale between green and brown, what you might call brown, I see as green, but at either end I can see the parent colors. True colorblindness, or monochromacy, results in seeing only black, white and shades of gray and is extremely rare. Check out this web site for an excellent review of colorblindness and a chance to see how I experience things. http://micro.magnet.fsu.edu/primer/java/humanvision/colorblindness/
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