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  1. #1
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    Race and DNA (again)

    The RST claim that the foreign DNA came from a male caucasian who is not a RAmsey. Some RST make snide remarks about the "BORG" suggestion that the foreign DNA in JonBenet's knickers came from a factory - asking how many white males work in asian sweat shops.

    I have been following this case since the year 2000 and I have learned a LITTLE bit about forensics in that time - I certainly don't claim to be an expert. I'm uncomfortable with unsubstantiated information though and the male, caucasian DNA IMO is unsubstantiated.

    I believe that it may be a false rumour which has come about as a result of two other (probably) factual pieces of information:-

    1) that a hair found on the blanket was caucasian
    2) the DNA in her knickers was male

    Mitochondrial DNA from hair
    The DNA which is extracted from hair is called mitochondrial DNA or mtDNA and it is often possible to determine race from mtDNA - but only because scientists undertook a massive study of mtDNA and built a database of information - including race. mtDNA is passed through the maternal line and therefore entire ancestral trees can be mapped with it. However, sex cannot be determined from mtDNA.

    Nuclear DNA
    This is the more common DNA and it contains more information than mtDNA. It is found in blood, saliva, skin cells, semen - even urine. It IS possible to determine sex from nuclear DNA but race is more problematic because nuclear DNA is passed sexually rather than matrilineally.

    In the most recent Schiller programme, it was claimed, yet again, that the DNA is that of a caucasian male and I have questioned the truth of this because it seems doubtful that race can be determined from nuclear DNA - and the DNA in the knickers was nuclear DNA - possibly from a cough or a sneeze (saliva/snot).

    On the other thread, I posted two sources which said that race could not be determined from DNA - one of these was dated 2003. I conceded that it might be possible that advances in science since then have made this possible - but I still questioned the source on Schiller's programme. The source is Bill Wise, former Boulder ADA who retired in 2000 and is IMO, long out of touch with the case and not a good source for such an important piece of information.

    Now I have found another source which is bang up to date and from an impeccable source:-

    Q: Tiffany, Westview Learning Center: What's the diffence between Asian people's DNA and white people's DNA?
    A: Jean McEwen, J.D., Ph.D.: There are no fundamental differences between the DNA of people from different "races." There are only differences in the frequencies of some genetic variants in people whose ancestors came from different geographical parts of the world. So, for example, people whose ancestors came from Asia may have a higher or lower frequency of a genetic variant associated with their responsiveness to a particular drug, or with their susceptibility to a certain disease, such as diabetes, heart disease, or stroke. Knowing about these frequency differences can be very useful for people's health care. However, there is a lot of ambiguity in the way people define their racial identity, which makes attempts to look for essential differences among "races" fraught with problems. For example, people who define themselves as "white" may have ancestry from many different parts of the world other than Europe. And all of us, regardless of the "race" we self-identify with, have ancestry from Africa. So we need to be very careful about making broad-based generalizations about genetically-based racial differences


    Q: St. Ignatius College Prep High School: Although we are flooded with references that claim racial differences cannot be traced to genes, it is clear that the FBI and associated police investigative agencies regularly use racial profiling for orienting their DNA testing data to specific criteria and for their statistical interpretations. How do we reconcile these two phenomena? There was news last fall that reported findings on a certain cluster of genes related to controlling some aspect of skin pigmentation. Will we hear more about the applications of this research in the future?
    A: Vence Bonham, J.D.: Race is a social construct that has changed over time. If you review how we have collected race in the history of the United States and other countries in the world it is clear that race is a social and political construct. Researchers and law enforcement agencies can use specfic biomarkers, including ancestral identification markers to make statistical estimates of an individual's ancestral background. This background may correlate with our social constructs of race. Researcher Keith Cheng and colleagues identified a gene called SLC24A5 which affects pigmentation (skin color) of humans. It would be a terrible mistake to conclude that a gene involved involved in skin color is really a gene for "race".



    Q: Brooke, illinois: Can you tell a person's race from DNA?
    A: Vence Bonham, J.D.: No. Race is a social construct and is not biological. You can learn about a person's ancestral background which may correlate with the person's self-identified race.


    Source - the National Human Genome Research institute
    Date - 25th April 2006

    http://www.genome.gov/18516768
    This is only my opinion

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  2. #2
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    Here's a study which challenges the belief that race cannot be determined by DNA.

    [quote]A recent study conducted at the Stanford Medical School challenges the widely held belief that race is only a social construct and provides evidence that race has genetic implications
    /quote]

    http://daily.stanford.edu/tempo?page...y=0001_article

    It is dated February 2005 - several years after Bill Wise retired :-)
    This is only my opinion

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  3. #3
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    More on the same study:-

    http://isteve.blogspot.com/2005/02/n...h-on-race.html

    Not clear, but it seems that Risch has found that race can be determined via biological predisposition to certain health factors (nothing new there).

    i.e. find the DNA information for sickle-cell anaemia and that person is almost certainly black

    He states that his samples could be split into 4 racial categories and that only one of these categories could be further divided (East Asian had separate subcategories for Chinese and Japanese).

    I am looking for peer review on this study as that seems to be important for scientific credibility.
    This is only my opinion

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  4. #4
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    Actually, in this article, Rische is agreeing with the Genome scientists:-


    Neil Risch of Stanford University, a leader in the field of genetics, contends that race is helpful for understanding ethnic differences in disease and responses to disease.
    When they said:-

    So, for example, people whose ancestors came from Asia may have a higher or lower frequency of a genetic variant associated with their responsiveness to a particular drug, or with their susceptibility to a certain disease, such as diabetes, heart disease, or stroke.

    This is only my opinion

    Let the focus be on Madeleine




    Together we can make a difference





    Alert Viewer in Scotland

    Member of Websleuths since April 2000