What are people best suited for?

Perfection is one step away from extinction.

Our tutoring consultant is helping chemistry students though their first weeks of class.  One type of problem they face is a “limiting reactant” problem: given so many grams of one chemical and so many grams of another, when they react, which is left over?  It’s the rare reaction where everything works out exactly evenly.

Our astronomer was thinking of this while doing his run along the Potomac River path, and concluded that the human body works sort of the same way.  Sometimes his performance is limited by stiff muscles; other times, by shortness of breath; still others, by his ability to stay cool in the summer humidity.  It’s rare that conditions are so evenly balanced that all limitations kick in at the same speed, or distance.

From this one could postulate that his body is optimized for one set of conditions, one combination of speed, distance and weather.  Going much further, some people have concluded that humans are best adapted biologically to the life they led when the species evolved from its ancestors: as small bands of hunter-gatherers.  In this view, it is much healthier to eat a paleo-diet of meat and wild plants than to consume farmed crops.  Wheat bread is held to be worse for you than hamburger, because we evolved to eat the latter and not the former (which is a very recent innovation, only 10,000 years old).

There is no doubt that most people today eat food that is moderately to very unhealthy, and too much of it.  Fats and sugar are over-represented, empty calories ingested solely because they taste good.  But we think there’s a flaw in the logic of optimization.

Humans survive in all climates of the world, eating what is available.  They have adapted to an enormous range of conditions, from hunting seals in the Arctic to farming cassava in Africa to eating fast-food take-out in New York.  It is the flexibility of the species that gives it success.  It can even survive in the terrible conditions it creates for itself, beyond the imagination of Nature.

The paleo-diet could be more healthy than cereal-based eating; we do not claim special expertise in medicine, so we won’t offer an opinion.  But it seems to us that, if humans were sharply optimized for a hunter-gatherer life, we would not have survived civilization.  A perfectly adapted species becomes terribly dependant on conditions staying the way they are.  Optimization is one step away from extinction.