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Breakthrough In Human Genetics

Many readers have submitted this story about a breakthrough in our understanding of human DNA: in particular, how much variation can exist between peoples' genes and how genes are involved with certain diseases. "One person's DNA code can be as much as 10 percent different from another's, researchers said on Wednesday in a finding that questions the idea that everyone on Earth is 99.9 percent identical genetically. They said their new version of the human genetic map, or 'book of life,' fills in many missing pages and chapters to explain how genes are involved in common diseases. The Human Genome Project mapped the billions of letters that make up the human genetic code. Scientists later refined the map by looking for single variations called SNPs or single nucleotide polymorphisms. The CNV map gives researchers a different way to look for genes linked to diseases by identifying gains, losses, and alterations in the genome."

13 of 240 comments (clear)

  1. chimpanzees=98% human by circletimessquare · · Score: 3, Interesting

    i remember reading that humans and chimps are 98% the same

    and previous to this announcement, all people were 99.9% the same

    the implication here is that people are actually as low as 99% the same

    which means one crazy ass inference:

    it should be possible to find two people and a chimp such that and person A is equally different from the chimpanzee as he is from the person B

    no way

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    1. Re:chimpanzees=98% human by qewl · · Score: 2, Interesting

      Reminds me of the old bumper sticker- "Bush is a Punk-Ass Chump" That I always misread (or perhaps more accurately) as "Bush is a Punk-Ass Chimp"

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  2. Um... not quite. by Punchcardz · · Score: 5, Interesting

    "One person's DNA code can be as much as 10 percent different from another's, researchers said on Wednesday in a finding that questions the idea that everyone on Earth is 99.9 percent identical genetically." It doesn't call it into question at all. The simple matter is that how you define "different" and measure the percentages makes a big difference. The human genome is ~3 billion base pairs. You can have a singe nucleotide change in a gene of say 5000 base pairs. When you compare a given gene between individuals, do you count the whole gene as being entirely different? Or do you say that it is 99.98% (4999/5000) the same?

  3. Gene Expression? by foobsr · · Score: 1, Interesting

    It is always interesting to see how they ignore gene expression, the role of the extracellular matrix (where much of it happens), the importance of mechanotransduction (tensegrity, see Ingber) and thus posture (as a way to cope with gravity as a constant stimulus) when it comes to causes for deseases.

    Well, salesdroids of the pharmaceutical industry, IMHO.

    CC.

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  4. God vs Man by eebra82 · · Score: 3, Interesting

    Does anyone know what stance our major religions have on DNA? For example, how should a true Christian receive this news?

    I know it's not entirely on topic, but seeing that the bible describes humans as flesh and blood and as one, it would be interesting to see what this up-to-ten-percent-difference would put science against religious belief.

  5. Differences between people by Bob54321 · · Score: 3, Interesting

    That 10% is way off. There is on average a variable base (across all people) every 300 bases. So by my calculations, people are at least 1 - 1/300 = 99.7% similar. Not everyone can be different everywhere so that gets us back in the 99.9% territory. The copy number variation map has not changed those numbers that much...

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  6. 10% variation by goldcd · · Score: 2, Interesting

    doesn't mean anything unless it's 10% of the genome that's actually expressed, or if it is creates a functionally different protein. Working on the assumption that we do actually evolve, then we'd need to have sections of DNA that can alter without having an immediate effect - like a scribble pad where stuff could just be doodled.

  7. Genes probably don't matter so much by mveloso · · Score: 4, Interesting

    Even if two genomes are 100% the same, that doesn't mean that the products of each will be the same.

    Why? Gene expression can differ depending on environmental factors.

    As a simple analogy, your DNA = a cookbook. While many recipies are cooked automatically by the systems in your body, other recipies are cooked or not cooked depending on the environment in which the organism finds itself.

    I haven't read a good article on gene expression, really. Various mechanisms are alluded to in the literature, but it seems to be unclear how gene expression is or is not triggered. More specifically, researchers seem to know that this particular mechanism turns a given gene on or off, but how that mechanism is triggered is unknown (or not the focus of the article/research).

    Also, I'd guess that environmental gene expression stars in the womb - that the fetus gets clues to the external environment from the nutrients and chemicals coming from the mother and adjusts itself accordingly. You could test that by somehow getting ahold of some in-vitro twins and implanting them at different times, I guess? But there probably still would be too many variables.

    1. Re:Genes probably don't matter so much by KokorHekkus · · Score: 3, Interesting
      Also, I'd guess that environmental gene expression stars in the womb - that the fetus gets clues to the external environment from the nutrients and chemicals coming from the mother and adjusts itself accordingly. You could test that by somehow getting ahold of some in-vitro twins and implanting them at different times, I guess? But there probably still would be too many variables.
      There was a very interesting BBC documentary "The Ghost In Your Genes" (http://www.bbc.co.uk/sn/tvradio/programmes/horizo n/ghostgenes.shtml) where they mentioned several interesting results about environmental effects on gene expression. In the program (and linked BBC article) one researcher mentions that he could turn some gene expression on and off in mice embryos by physically manipulating the embryos.

      One very interesting thing they also talked about was the possible transgenerational effects by famine as an example of how environments affects the human organism. Överkalix in far northern Sweden was very isolated so there were struck by famine several times. Being Swedes they were also kept very good records of births, deaths etc. A researcher decided to look at the health of those families over 3 generations. I'd say they found something quite astounding: there was a link in grandmothers food supply and their granddaugters mortality rate, same for grandfathers and their grandsons (the link was either all on the male line or all on the female line).

      For those who wish to read a little more about the transgenerational the researchers has written an (non-scholar) article at the University of Bristols website http://www.bris.ac.uk/news/2005/866. I think there will a lot of really interesting developments in the gene expression research in the coming years.
  8. Natural Selection no longer applies to humans by DeadCatX2 · · Score: 4, Interesting

    Humans have escaped the phenomenon of Natural Selection, for the most part.

    All of us who wear glasses? We should have been culled. All these people developing diabetes from eating too much sugar? Selected against. Asthma? You get the picture.

    Running with the idea that there is a higher power that created the world, I would say that Natural Selection is the method that higher power uses to figure out what works. But now with health care and a strong sense of altruism, errors in the genetic code are propagating throughout our species and wrecking havoc. In other words, we're playing god by saving lives that should have been selected against and allowing them to pass on their flawed genes.

    I also contend that if we were created by a higher power, and that higher power enabled us with the ability to modify our genetic code, then it is our right (nay, our duty) to do so; otherwise, we would lack this ability. I believe that we should selectively erase genes which cause a predisposition to things like Down Syndrome or diabetes or cancer, etc. This would effectively select against all detrimental mutations.

    This could also be the limit of Natural Selection as it tends toward infinitely fast; beneficial mutations in one human (for instance, the HIV resistance that elite supressors have) could be propagated throughout the species' genetic code in a single generation.

    Perhaps I should leave you with an example, one that even a Christian might be able to tolerate. Imagine a future where you and your s/o collect your eggs and screen them for genetic defects, like Down Syndrome. Once a viable egg has been found (and you don't have to look up what the hair color or eye color will be, you could just leave that to fate), start screening some sperm. Produce a viable fetus which will grow up to be healthy.

    Now imagine that you were one of those people who didn't do that for your kid. And now your kid is born with a gene that means they're 80% likely to die from some horrible disease by the age of 30. If I were that kid, I would be pissed at my parents for not choosing the screening option.

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  9. I disagree, there is still 'natural' selection by Iloinen+Lohikrme · · Score: 2, Interesting

    If we think that natural selection just means survival of the strongest or fittest, then the humankind should have died a long a go. For almost its entire history humankind has been dinner in dishes of predators. If you put a human and a lion one against another, the lion wins. The key in success of man has been group work, working together to achieve common goals: hunting, defending against predators etc.. In this backdrop having a bad eyesight or asthma doesn't matter so much, individuals with these negative attributes could still specialise on some other talent form. And keeping in mind that there has always been more individuals wanting to join a successful group than there has been inner need in that group, has kept the competition going on and 'natural' selection has taken it's care.

    If we look at our current society where almost every baby is been saved and poor people have more children than rich, it could look like there is no natural selection going on, and thus one could think that degeneration of human genetic code is going on. I don't think that this is the case. It could be the case if there would be strong social barriers between different classes of society, but now there isn't, and people can mix and match on their own basis, selecting the most suitable partner for them. Also one variable to consider is that humans have developed very much information regarding how to live life and how groups should work, and thus the race is also going on in a cultural front. If we look a child, he/she gets very much cultural information from the beginning that influence ones later success in life. All in all I think that we are running in the right direction.

    On a different note, I also applaud genetic screening for defects, but only on clear cases like the mentioned Down syndrome. Screening something like the 'criminal' or 'gay' gene, would not yield success and if used in a large scale would lead to a shift in society: there has to be enough aggressive people and people liking to dress pink ;)

  10. Race and genetics by Dobeln · · Score: 3, Interesting

    From the article in the Independent referenced elsewhere in this thread:

    http://news.independent.co.uk/world/science_techno logy/article2007490.ece

    "The scientists looked at people from three broad racial groups - African, Asian and European. Although there was an underlying similarity in terms of how common it was for genes to be copied, there were enough racial differences to assign every person bar one to their correct ethnic origin. This might help forensic scientists wishing to know more about the race of a suspect."

    In short, this research supports the notion that race is a useful and scientifically supported concept. Indeed, virtually all new data coming in on human genetic differences go against the fashionable yet not-very-well-supported notion that "race does not exist". How strange.

  11. Re:Spelling on Slashdot by TheABomb · · Score: 2, Interesting
    But for the chimpanzee-human adage to be correct, there would have to be less than 2 percent variation between any two humans. A difference of 10 percent of two percent, 0.2 percent, would still leave everyone at least 99.8 percent the same, and that's hardly newsworthy enough to make a story.

    And if you RTFA, the project apparently only worked with 12 percent of the total DNA. That means that at least there's 1.2 percent difference to work with, unless the supposed 10 percent is actually 5/6 of that 12 percent, in which case we could each theoretically be 83 percent different. I'm rooting for that, because the logical next step from there is X-Men.

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