Not very long ago I noticed that a pair of rubber boots that I had only been able to pull on over my calves with effort now slipped on with ease.  I carefully inspected the boots.  There had to be a rip in the side.  Nothing was wrong.  My calves had shrunk.  At about the same time I noticed that there was nothing in the rear to hold my pants up.  Where had those tight gluts gone? 

I had to buy a little electric trimmer to get rid of those, you know, unwanted hairs that, overnight, seemed to be growing down out of my nose onto my mustache. 

The hair stylist asked me if I wanted her to trim my eyebrows.  My eyebrows?  Yes, my eyebrows.  While I wasn’t looking I had developed a Leonid Brezhnev look.  You remember Mr. Brezhnev.  He had eyebrows that looked like some sort of scrubby with hairs that spiraled off in pursuit of Mir, the soviet space station.

I took a careful inventory and discovered that tufts of hair were growing out of my ears.  Aaargh!!!  My body had turned on me.  That perfect machine that I had taken for granted was manufacturing new parts with no apparent purpose.

What was behind all of this?

Everyone knows what primary sex characteristics are.  They’re how you decide whether you’ve had a boy or a girl.  Secondary sex characteristics come along a decade or so later resulting in a change in body shape, hair growth, and voice change all accompanied by emotional turmoil, insecurity, and fascination with the idea of becoming intimate with another person.

What happens later in life is usually chalked up to aging, but it just could be that the changes described above are tertiary sex characteristics. “Tertiary sex characteristics?” you ask.  What would be the purpose of those?  Simple, they convey the message, “No longer a player.”  What does your DNA want?  It wants you to know that a potential sex partner is going to be able to have children or father children AND that they are going to be around long enough to raise and care for them.  What better way than hair growing on a woman’s lip, out of a man’s ears and nose, muscular atrophy associated with an expanding midriff? Yuck, all of those things we don’t want to happen as we will continue to try to be sexually attractive.  Since our teens this attractiveness is something that we were anxious to maintain and enhance.  Now, our bodies have turned on us in a perverse way. 

DNA is tricky stuff.  It has its own agenda and considers yours irrelevant.  In some ways it seems to be your worst enemy.  In other ways it seems the other way around.

Consider the latter case.  Does it make sense that we become sexually mature at the beginning of our teen years?  Sure we can reproduce, but what about child rearing?  Becoming pregnant at 12 is usually a disaster for both mother and child.  Maybe it hasn’t always been so.  At the dawn of our species when we traveled in groups gathering seeds and roots, snaring some small animal and, occasionally killing a larger animal the tribe raised the child’s child.  With both infant and adult mortality high it would make sense to be replacing the casualties as fast as possible.

Today, in a complex technical world that requires extended education and multiple years to complete, and in a society that provides little child rearing assistance to new mothers, it makes sense to put off having children until the mid to late 20s.  Yet our DNA hasn’t made the adjustment.  It could be that it just hasn’t had time.  After all, we’ve only had this highly technical society for a few hundred years.  On the grand scale of human evolution that is a tick on the evolutionary clock.

The other possibility is that the DNA knows this can’t last.  That there will be a worldwide collapse of civilization through some means that we can only imagine; an event for which we are ill equipped to prepare. That’s probably not the case.  DNA is not that smart.  It is, however, consistent in its goal, to preserve itself by whatever scheme that works.  In doing so it sometimes adopts strategies that increase the chances for overall survival while sacrificing a small number.  The case of the sickle cell trait comes to mind.  The trait which occurs twice as often as the disease when two carriers mate protects against malaria, while the untreated sickle cell disease is a tragedy that results in anemia, pain, and early death.  DNA can be coldly ruthless in its single minded purpose of reproducing itself.

Fortunately, there is life after child rearing and a certain peace in being good company for our mates.  Maybe our genes planned this phase, too.  The grandparent phase during which we can help out those kids having kids by being loving family members who impart a little wisdom while spoiling the little rascals rotten may also be part of our DNAs master plan.

Are they comparing the relative merits of Cross vs. Parker pens?