genetic hotspots in humans

Discussion in 'Creation vs. Evolution' started by Helen, Jul 27, 2003.

  1. Helen

    Helen
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    First the article, then my comment:

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    Source: University Of Texas Southwestern Medical Center At Dallas
    Date:
    2003-07-15


    UT Southwestern Researchers Define Regions Of Human Genes Highly Prone To Mutation
    DALLAS – July 14, 2003 – UT Southwestern Medical Center at Dallas researchers have taken the first step in defining the sites in human genes most prone to mutation, which eventually could lead to discovery of the genetic bases of many human diseases.

    Their work will appear in an upcoming issue of the journal Gene and is currently available online.

    Dr. Harold "Skip" Garner, professor of biochemistry and internal medicine, and his colleagues made their discovery while mining databases of coding single nucleotide polymorphisms (cSNPs) held by the National Center for Biotechnology Information, the SNP Consortium, the National Cancer Institute and the Institute of Medical Genetics at Cardiff, Wales. Single nucleotide polymorphisms (SNPs) are the most common and simplest form of genetic mutation in the human genome.

    In their analysis, the researchers showed that a large fraction of human cSNPs occur at only a few distinctive and usually recurrent DNA sequence patterns. However, such events within the genome account for a disproportionate amount of all gene point mutations.

    Developing an association between phenotype (the outward, physical manifestation) and genotype (the internally coded, inheritable information) is vital toward understanding and identifying indications of disease.

    "This discovery can be used to essentially define the likelihood of one gene to mutate relative to others as a function of both time and environment," said Monica M. Horvath, molecular biophysics graduate student and co-author. "cSNP trends are critical to quantify in order to develop hypotheses regarding the complexity and range of mutational mechanisms that generate both genome diversity and disease."

    The next phase, Ms. Horvath said, is to employ both experimental and computational tests to benchmark how well these trends can predict mutations not yet found in the human genome.

    "What I like the most about this work is that it shows that as proteins evolve, natural selection has considerable latitude, not only in determining the amino acid sequence of a protein, but also in determining how frequently and severely to break it," said John W. Fondon III, molecular biophysics graduate student and contributing author.

    "What Ms. Horvath has done is to essentially crack the code within the code – to reveal how selection exploits redundancy within the genetic code to specify whether a particular amino acid letter in a protein is written in stone, with ink, or in wet sand at low tide."

    An important application of this research is that with enhanced knowledge of where mutations are most likely to occur, medical geneticists can take more aggressive approaches to discover the genetic basis of many human diseases.

    "We know the genome is very big, and there currently is no technology to remeasure every single letter of this 3-billion-letter code," said Dr. Garner.

    "A very significant byproduct of this research into the complex interplay between mutation and selection is that Ms. Horvath has revealed some clear rules that can contribute to the design and execution of genetic association studies. This will become an important component of the solution to the currently intractable problems presented by complex diseases that involve many genes."


    The research was supported by a National Institute of Health grant, Program in Genomic Applications grant, the Biological Chemical Countermeasures program of The University of Texas and the state of Texas Advanced Technology Program.


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    This story has been adapted from a news release issued by University Of Texas Southwestern Medical Center At Dallas.


    from
    http://www.sciencedaily.com/releases/2003/07/030715090420.htm

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    My comment is short: please note that this work with rapid mutations has nothing to do with mankind evolving to something 'better' but rather with diseases which happen with mutations.

    Interesting.... [​IMG]
     
  2. ColoradoFB

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    From reading the article, it appears that no one has suggested it is explicitly about human evolution. So what is your point?
     
  3. Helen

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    my point is that the most common mutations all evidently are connected with problems for the species, nothing 'beneficial'. With this kind of a load building up rather rapidly, how do the 'beneficial' mutations get from an ape ancestor to us?

    They are studying mutations for the purpose of curing illnesses and problems, not because they seriously are thinking that any of these mutations are going to help anyone...
     
  4. NeilUnreal

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    Good article.

    My counterpoint:

    This is also an ongoing topic of interest in genetic algorithms (GA) and evolutionary programming (EP). The "evolution of evolveability" is something that is predictable from the modern synthesis.

    -Neil
     
  5. Peter101

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    &gt;&gt;&gt;&gt;&gt;&gt;my point is that the most common mutations all evidently are connected with problems for the species, nothing 'beneficial'. With this kind of a load building up rather rapidly, how do the 'beneficial' mutations get from an ape ancestor to us?&lt;&lt;&lt;&lt;&lt;

    There is no evidence that there is any load of genetic problems building up. Note also that evolution is an important basis for the research. Beneficial mutations will almost certainly be retained merely because they are helpful. There is some current research that hints at ways in which mute ape-like ancestor may have undergone mutations that allowed them to speak. Maybe in the future the details will be worked out.
     
  6. Helen

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    oh help....

    Genetic load is building.

    "Beneficial" mutations are not necessarily retained.

    Those are simply statements of fact.
     
  7. Peter101

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    &gt;&gt;&gt;&gt;&gt;Genetic load is building.

    "Beneficial" mutations are not necessarily retained.

    Those are simply statements of fact.&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;&lt;


    They are claims without any support, not facts.
     
  8. Paul of Eugene

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    What is the appropriate genetic load level for a steady state of genetic load for the human species? I don't think we can figure that out yet. Our species has embarked on a new path never before taken by any other, the path of technological savvy and techological environmental manipulation. Is it genetic load if every member of the species needs glasses to see clearly? It is if you are a species that can't make glasses. Maybe not if you can.

    Don't forget the environment is not the only selection mechanism out there. Don't ever forget the effect of sexual selection. Who do you choose to bear your children, father your children? Yes, choices are made and this influences the future of the species. There is more going on out there in terms of having the next generation be healthy than meets the eye.

    The genetic doom of mankind is not a done deal by a long shot!
     
  9. NeilUnreal

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    Genetic load, beneficial mutation, etc. are artificial constructs. All that really matters in RM&NS is whether one actual, physical, package of genes out-reproduces another in a situation of limited resources. In order for this to happen, genotypes must grow into phenotypes, and phenotypes must compete in an environment. We don't yet have a reliable general metric of genome viability.

    -Neil
     
  10. UTEOTW

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    1. "cSNP trends are critical to quantify in order to develop hypotheses regarding the complexity and range of mutational mechanisms that generate both genome diversity and disease."

    That diversity part might have somethng to do with evolution.

    2. What I like the most about this work is that it shows that as proteins evolve, natural selection has considerable latitude, not only in determining the amino acid sequence of a protein, but also in determining how frequently and severely to break it.

    Natural selection is being discussed and the evolution of proteins. Could be a little bit more about how evolution happens.

    3. It does not seem too surprising that an internal medicine professor would be more interested in the disease causing potential of mutations as far as the focus of the article goes.
     
  11. Paul of Eugene

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    Let's not be overly hasty here. Of course, some beneficial mutations aren't retained. Are you saying no child with a beneficial mutation ever died without leaving descendants? This doesn't affect evolution, of course, one way or the other, but it is a truism that some beneficial mutations don't get passed on.
     
  12. Peter101

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    &gt;&gt;&gt;&gt;Let's not be overly hasty here. Of course, some beneficial mutations aren't retained. Are you saying no child with a beneficial mutation ever died without leaving descendants? This doesn't affect evolution, of course, one way or the other, but it is a truism that some beneficial mutations don't get passed on. &lt;&lt;&lt;&lt;

    I was thinking mainly about the alleged genetic load that she mentioned. Of course not all beneficial mutations will be passed on, but there will be a tendancy for the good mutations to survive. We all agree that there are good mutations and bad mutations. What perhaps is not agreed upon is the relative quantity of each and the impact of each. The relative impact of each will depend on many factors. It is impossible to predict which will win out, it seems to me. We only see evidence that humankind has undergone mutations which gave us some desirable characteristics. Some of the that may be due solely to chance.

    If the same process were repeated again, chance might produce a different outcome. Neanderthals might now rule the world, rather than their cousins. We might now be listening to a female Neanderthal telling us that those vile homo Sapien cousins could not possibly have those God given characteristics that make Neanderthals such a favorite of the deity. After all, the Homo Sapiens did not have ridges above their eyebrows. How could any sane person believe that a person can be HUMAN without those characteristic ridges which separate true humans from the beasts? Ridges above the eyebrows are a characteristic of the intellectual nature of our Neanderthal society - everyone knows that of course. It is unlikely that those lower types of humans could even make arrowheads. The ones that are found with them were probably dropped coincidentally by our own kind.
     

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