How We Don't Work

In Nathan H. Lents book Human Errors: A Panorama of Our Glitches, from Pointless Bones to Broken Genes the author truly gives us a view of all the ways natural selection has failed to select positive traits.  This is not how we tend to view natural selection.  Traits that don’t help us survive should be eliminated.  But this ignores plentiful examples of shades of gray where a trait, while not positive, is not overly negative.  It may be a pain, or cause pain, but it does not affect reproduction.

Take bipedalism.  This change was crucial for our development, but our spines did not adjust well; we suffer from slipped and herniated disks because our spinal bones fail to fully support our upright stance.   We have bad sinuses because our largest sinuses are below the nose, and must be emptied through a small tube (defying gravity, another post-upright down side).  Our ancestors on all fours probably never got colds or sinus infections.

Lents most important point, at the end, is that we are the first creatures to have more or less eliminated natural selection.  Poor men can marry and have children.  A person with bad eyes will not be eaten by a predator.  We now mold our environment instead of it molding us.  The trick is, we will mold the world for our benefit and in the process destroy it?