On July 7, 2011 I was listening to NPR’s “All Things Considered” as I drove. A story perked up my ears entitled, “Have Sex to Stay One Evolutionary Step Ahead”. The story discussed the evolutionary advantage of having sex as opposed to reproducing asexually; the perceived advantage of asexual reproduction being that men often don’t contribute more than their DNA to the well-being of their progeny and we are a giant resource drain to boot! Statements like that make me straighten up a little in the butt ruts of my couch and brush the potato chip crumbs from my stomach in protest.
Anyway, scientists at Indiana University used earthworms to dissect the problem, “Why sex?” Since earthworms reproduce both sexually and asexually they are the perfect foil. They produced two sets of earthworms: one which could only reproduce asexually and another which could only reproduce sexually. Then they unleashed a bacterial parasite which ate the earthworms from the inside out, ouch. That is a real impetus to evolve quickly and a bit of a horror show.
So the inevitable happened to the asexual set and they went the way of the dodo bird. The sexual set got busy and evolved quickly to outpace the advances of the parasite. Incidentally the report stated as an aside that the earthworms had lots of sex and produced a lot of boys. This was presented as an ironic fact, like see boys do serve a purpose after all we even produced a plethora of them. It caught my attention as something more though, why so many boys? So the girls can have an abundance of choice. When women have an abundance of choice they don’t just go with “whatever” they choose the best, this is real evolution and it’s not as random as some would propose.
Though what would happen if the sexual earthworms refused to reproduce or took a pill which not only did that but also altered their perception of what constitutes an adequate partner? That would end in disaster right? The sexual become far less adaptable, it would slow evolution to a crawl and the chance of evolving optimally would be significantly impaired. This impairment focuses upon the individual’s propensity for picking mates who have MHC genes which are the most unlike their own. MHC genes are the genes which have to do with an individual’s immune system of all things, dude I mean what a coincidence, I mean seriously! The study most are familiar with would be the University College of London study, studies by the University of New Mexico, University of California, LA, and Duke show the same results; these are the few I found without looking too hard there are probably more if you are one of those people who are able to attract females who are not on the pill. (That was just a small joke dear.)
If women are incapable of choosing partners who have immune systems which are significantly different from their own and they do not wish to procreate anyway then we are not only equivalent to the asexual worms, whose immune systems were all identical, but we are actually lagging behind them because at least they were trying to reproduce. I hate to sound gloomy though so I will just close with well wishes to all, enjoy your flesh eating parasites!
No comments:
Post a Comment