Saturday, December 07, 2013

Why the Y?

Maureen Dowd opinionated sarcastically in her column recently about the incredibly shrinking Y chromosome, the male DNA molecule.  She sat in a classroom at MIT on the subject “Are Males Really Necessary?”
She repeated two questions from the class:
“Since only females can give birth, why is it of any advantage to the species to have a second sex?”
“Why should nature bother with males?”
MoDo referred to the differences in reproduction between sex as meiosis and cloning as parthenogenesis.  Like her, I’ll just go with the common terms.
Answer to the first question: none to little advantage for “a” species.  Once a species has evolved, cloning would keep life going generation after generation almost as well as sexual mixing of genes. 
The advantage comes during a plague or pandemic.  We can see this in history for groups isolated or remote when exposed to an infectious agent.  Because of restricted selection and the resulting interbreeding within secluded group, their offspring are very similar to clones, and a contagious disease could wipeout the entire group.  Whether the infection was newly introduced or some local virus that mutated or evolved, the results are the same.  Those pesky viruses swap genes, and any species that mingles its gene has the advantage over those that don’t.
As to the answer to the second question, nature does not “bother with males”, their presents takes advantage of evolution’s driving mechanism.  They are there because nature chose sex overwhelmingly compared to cloning.  Sex was one of nature’s greatest invention – or mutation, since only humans invent or create what was not there before.  Nature does not create; it just rolls the dice.  Winning numbers keep rolling; losing number go extinct.  Sex not only survived, it exploited evolution like no life had before.   Speciation occurred because of the greater chance of a successful mutation with sex.
Now it is true that in most species, males are only sperm providers.  Females do everything else.  Not all females reproduce but mothers, daughters, aunts, and female cousins run the pack, pride, and hive in most species.  Male dominates in our species is the rare but not an entirely singular exception.
The important issue not mentioned in MoDo’s column or in the MIT class she attended is the fact that while males are not longer needed, neither are females.   True, only females can carry life from conceptions to birth, but those days are numbered.  We are on the verge of doing gestations within a machine.  Not only males are obsolete; but so will be females, probably before the end of this century. 
While males and sex was chosen by natural selection, evolution has ended.  Our species has taken over evolution.  It was the survival of the fittest; it is now survival as we see fit.  We have driven some species to extinction, and through agricultural and cultivation, altered selected species to fit our needs, mostly for food, but also for fun and our own amusement. 
Now, we are of doing this not by selectively breeding the traits we want but by altering the DNA molecule directly.  We do not know exactly how DNA works in detail, which gene or combination of genes produces specific traits, behaviors, or working body parts, but we will eventually.  Like producing babies outside a woman’s body, this too will occur in this century.  We could choose to clone females or we could clone males – or both or something in-between.  Not why the Y, but why the XX, also.
Links to this post

0 Comments:

Post a Comment

Links to this post:

Create a Link

<< Home

Links to this post:

Create a Link