02/12/2013 04:07 pm ET Updated Apr 14, 2013

The PRH (Personal Responsibility for Health) Chronicles, Part 3: Then and Now

Please also see "The PRH Chronicles, Part 1: The Way We Were" and "The PRH Chronicles, Part 2: The Way We Are"

Mik-tal was left to wonder whether Bo-tu and the other hunters would return. One might wish for a Hollywood ending, a successful hunt, a satisfying resolution. A family happily reunited, a clan secure.

But even if Bo-tu returns, Mik-tal, Kanda and the others are no more assured than before of living happily ever after. In the world of our ancestors, life was a constant struggle, a constant state of uncertainty. If Bo-tu did return, some other hunter, with some other mate and some other child did not. Precarious in the predictable redundancies of occasional feast and persistent famine, survival was a contest sometimes won, often lost. And those that won did so in increments that themselves perpetuated uncertainty. One more generation would continue the struggle, and the uncertainty. Until the eons passed, the world changed, and the age of modern plenty arrived.

You may decide for yourself if Bo-tu returned. Truly what mattered then and consequently matters still is the uncertainty. Our ancestors, those that did survive, did not know any more certainly than those that did not (never to become ancestors), that they would overcome the hazards of their world. Everything of consequence was overshadowed by an uncertain supply of food. Every aspect of physiology and culture shaped itself around the overriding reality of life: Enough food meant survival, too little, demise.

If Bo-tu returned, there was the chance that on some subsequent outing he would not. Mik-tal knew this all too well. She lived with this uncertainty, and in accordance with its harsh demands. And passed it along to her children. And they to theirs, through all the ages. Only by knowing Mik-tal's endowment to us can we hope to meet the challenges of the modern world. Our efforts to find our way home begin by knowing where home is, and where we are now. Our efforts to achieve dietary health begin by knowing ourselves.

The human genome, the blueprint responsible for much of what we are, has not changed appreciably in 100,000 years. That takes us back to countless generations before Mik-tal and Bo-tu. Their genes are our genes. The implication is that their traits, their metabolism, their physiology are ours, too. Mik-tal and Bo-tu are Michelle and Peter; and Michelle and Peter are us.


-The PRH Chronicles will continue...

Dr. David L. Katz;

For more by David Katz, M.D., click here.

For more on personal health, click here.