According to researcher, Huntington Willard, of Duke University, there is an actual genetic difference in the complexity of the women's genome and the men's genome. Willard says that the difference is so dramatic, we may have to start saying there are two human genomes, instead of one.
That's because on the 23rd chromosomal pair of the typical human , a female will have two X chromosomes while a male will have only one X chromosome, the other chromosome being a Y chromosome. The Y chromosome holds considerably fewer genes than the X chromosome but it has the important job of coding for maleness. It does this by either coding for maleness directly or by suppressing what's on the X chromosome.
But males do get one X chromosome on that 23rd pair and they, too, have the ability to code for whatever is registered on that X chromosome (at least in as far as those traits are not suppressed by the Y chromosome). In other words, males are not less than human simply because they don't have two X chromosomes ... notwithstanding what some might say to the contrary, especially those of us who lived among brothers during our formative years.
Consequently, at first glance, you might be tempted to suggest that because of the Y chromosome, it is the male who is obviously more varied and it is the male who is more complicated genetically. There would seem to be more variety in having an X and Y chromosome than in having two X chromosomes. But, according to Willard, you'd be wrong.
What Willard points out in the April edition of the journal, "Nature," is that the female is considerably more complicated exactly because she gets TWO X chromosomes in her genetic makeup kit. Each one of those X chromosomes has the same genes on it to code for the same human traits but each of those two genes comes from two different parents and, therein, lies the source of variation. The same gene on the X chromosome from Mom can vary considerably from the corresponding gene on the X chromosome from Dad. If Mom and Dad have two variations of the same gene and we look at all the different genes on the X chromosome and we start factoring in how many different combinatory ways there are in which all these genes can express themselves, we end up with a whole bunch of complication not seen with the single X on the XY chromosomal pair. On the XY pair, the genes on the X have no competition to their expression.
This makes for a much more complicated gene-set of possibilities in a woman than we see in a man, who carries only the X genes his mother passed to him. The woman's genetic makeup kit is more complicated precisely because she has two X chromosomes from two different parents.
It looks like we finally have a scientific basis for saying "women are more complicated than men." That's right ... your gut instinct about this matter was on target all along.
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