27 September 2012

Proof That We're Not Just XX Or XY?

I'll admit:  It's been a long time since I've studied biology.  So, my knowledge is probably rusty, to put it mildly.

So I wouldn't be surprised if something I learned as one of the most basic tenets of genetics has been overturned.  Said notion is that males and females are determined and identified at the chromosomal level, and that there is "male" and "female" DNA.  The former has, of course, XY chromosomes and the latter, XX.

Well, like many ideas based on binaries, it seems as though that one might be overturned, or at least may need to be modified.  At least, that's what new research seems to indicate.

According to the study's lead author, Dr. J. Lee Nelson of the University of Alberta, the findings "point to the need for a new paradigm of what the self is, biologically".  

What is causing Dr. Nelson to make such an earth-shattering statement?  His team has found male DNA inside female brains.

The study found male michocherism--"the 'intermingling' of small numbers of cells or portions of DNA in a person from a genetically different individual"--in 63 percent of the brains tested.  

These findings are significant for a number of reasons.  For one, the researchers found that female Alzheimer's patients have lower concentrations of "male" DNA in the portions of the brain most affected by the disease.  This, of course, could have significant implications for those researching Alzheimers, and possibly other conditions.

Also, if a person can have "immigrant" DNA intermingled in his or her cells, the notion that DNA can uniquely identify an individual human being is challenged, to say the least.  That undermines one of the most basic notions of genetic science, not to mention the notion that gender is identifiable and definable by DNA structure.  Some might argue that such a notion might have gone by the wayside in any event, as DNA structure often has very little to do with the way terms such as "male" or "female" actually function in the world, let alone with how people actually live as men, women, boys, girls or in other gender identities.

Perhaps Dr. Nelson summed up the implications of his findings best when he said, "I think we're better off defining it [the biological self] as an ecosystem, rather than as a singular genetic template, with more genetic and cellular diversity than we previously thought."

Could this spell the end of the gender binary after all?