Genetic Variation (Introduction)

by xeno6696 , Sonoran Desert, Friday, September 24, 2010, 04:58 (5154 days ago) @ Balance_Maintained

A spin off of research related to the Neanderthal discussion led me to this article. Notice in particular, the following quote:
> 
> >Ironically, the variation in PRDM9 is due to a minisatellite within the gene itself. Sir Alec said: 'I've come full circle -- starting out with minisatellites to develop DNA fingerprinting, and arriving at a gene containing a minisatellite that plays a key role in driving all kinds of human DNA diversity, including variation at minisatellites. An intriguing possibility is that it is even driving its own evolution!'
> >Sir Alec believes the research, along with that of others working in the field, will inevitably further scientists' ability to understand the basic processes that make us all genetically unique, as well as defining an entirely new class of genetic risk factor for numerous disease-causing DNA rearrangements that can arise when recombination goes wrong.
> >These findings also provide a neat solution to one great puzzle of recombination hotspots -- namely that they appear and disappear rapidly during evolution. Sir Alec said 'We've shown that hotspots have a strange propensity for self-destruction, so how can they possibly exist? The PRDM9 minisatellite gives the answer -- it evolves rapidly, like any other unstable minisatellite, and keeps churning out variants that can trigger new hotspots, replenishing those that have committed suicide. A totally crazy mechanism to ensure that recombination keeps going, but typical of the weird solutions that evolution can throw up'.
> 
> 
> Now to me, there are several bits out of this piece that are interesting and disturbing. The first interesting bit for me is the statement: "An intriguing possibility is that it is even driving its own evolution!" The reason this is so interesting to me is that it seems to go against the grain of mainstream evolutionary theory. The standard theory is that 'random' mutations occur, and that these mutations are naturally selected based off what is useful or proactive towards the goal of survival. Then, they make a contradiction that states that external/internal pressures trigger these adaptations/genetic changes. If the changes are pressured or triggered to occur, then they can not, by definition, be truly random, but are in fact a result of cause and effect. Now, they bring in a third contradiction, namely that the mutations are not in-fact truly random at all, nor a result of external pressure, but instead are the result of a 'mini-satellite' tossing bits of code out to ensure genetic variability. 
> -The only problem here is... aside from Dawkins--evolution is generally not considered "random." Read "Denying Evolution" from Massimo Pigliucci. -But even if we were to assert "randomness," the fact that a random outside event would cause any number of internal events is itself not random. However it is still cause and effect. You have a false dilemma here. -
> Which brings me to the next curiosity that seems to be a logical inference from this discovery. This pseudo-code generator mini-satellite gene, if isolated in all species, would mean that would explain why we see variations on a theme within taxonomic classifications, but do not actually see species diversion between on distinct family, such as canines, and another, such as felines. The mini-satellite pseudo-code would provide for nearly infinite variation on a theme, but is limited to being able to affect only certain bits of the overall code. 
> -So... in other words--it explains genetic recombination. Sorry--still don't see teleology here! -> The third part, and by far the most disturbing to me, was the implication for this discovery on modern day humanity. Science, in general, does not know when to leave well enough alone(Manhattan Project Anyone? Biological weapons perhaps? Maybe chemical weapons are more your taste..). It has a tendency to do things because it can. It also likes to have pretty lines of data and stable trends and uniformity. When I read about scientist being able to use this data to predict genetic risk factors etc, I had the memory of a movie titled "Gattaca", where science used its predictive abilities to genetically 'screen' individuals, and created a caste separation between infants born from genetic compatibility and those born as 'love children'. I can also see them using this discovery in gene manipulation treatments that could effective make all humans genetically equal, which is even deadlier to the species.-Science generates models and tools. It is up to Ethics and philosophy to guide the use of those tools. Call me evil if you will, but I am firmly in the camp of "if we have the power to do something, we should." I qualify this with that the power is in serving humans as ends, not as means to ends. -However, in my case I'm willing to suspend that ethic to defend myself or my family if needed. This includes--nuclear weapons.-
[EDIT]-I need to qualify the above a tad more. I believe that science should be unhindered whenever consequences are unknown. Slowed/cautioned only when humans are involved.

--
\"Why is it, Master, that ascetics fight with ascetics?\"

\"It is, brahmin, because of attachment to views, adherence to views, fixation on views, addiction to views, obsession with views, holding firmly to views that ascetics fight with ascetics.\"