Book Review

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life

N Engl J Med 1997; 337:137July 10, 1997

Article

On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life
(Collector's Edition.) By Charles Darwin. 470 pp., illustrated. Norwalk, Conn., The Easton Press, 1997. $43.25. No ISBN.

The Origin of Species is the most radical reconfiguration of our place in the universe — as individuals and as a single species — since Moses brought down the Torah from Sinai. It remains today what it was on the day it was published in 1859: a model of clear thinking and close observation, a set of predictions that seem to be borne out by experiment whenever they have been tested, and a vision of our origin that offers us no hope of finding purpose or perfectibility in the biology of our species, or in that of any other.

The argument of the book is as simple and lifeless as a crystal: all life shares a common ancestry; all differences among today's living things are the result of differential viability among the variants of previous forms; variation is intrinsic to life; and therefore a species can attain neither perfect form nor perfect stability. Until the past few decades, a serious person could take refuge from Darwin by claiming that the gene — the unit of inheritance of both stability and variation — could not be a simple chemical and that, therefore, the motor of natural selection might not be random mutation alone but might, instead, have an intrinsic direction. But DNA does what Darwin asked it to do, and today we cannot avoid accepting that life is, at the level of chemistry anyway, just DNA's way of making more DNA.

There are two excellent reasons for every practicing physician to own and read a copy of The Origin of Species. First, the Hippocratic oath and medicine itself are triumphs of our species' capacity to work against natural selection. Only by hundreds of thousands of years of suffering and dying can natural selection have winnowed out our ancestors from among their primate competitors. Every patient whose life is extended, whose quality of life is made better, whose suffering is reduced, is a novel interference with this ongoing process. Some may worry that interference of this sort will lead to the loss of our species' vitality; I see it as the very essence of our success.

The second reason for doctors to read Darwin is to see how different their job would be if his view of life were as complete as it is accurate. Simply put, Darwin ignored microbes. Every case of infectious disease — whether caused by virus, mycoplasma, bacterium, mold, or protist — is a little sampling of how natural selection works. The strategy our ancestors have followed since they first assembled into multicellular creatures bets on genetic stability and complexity to create a species made up of individuals, each with a reasonable chance of survival. The microbial strategy takes the opposite tack. Their genetic simplicity and malleability allow them to discard almost all progeny, always leaving a few genetic variants to survive any contingency.

If doctors today were able to show Darwin what they know about infectious disease, I am sure he would agree that the biggest threat natural selection poses to our species is neither another animal nor any possible “next step” born from us, but the invisible species that have been with us and in us from the beginning. The microbes' profligate strategy precedes ours, and there is no reason to think that we will ever design chemicals to outwit it; our immune system is our first, and remains our best, defense. Darwin would have really loved the idea of a vaccine. To see why, read the book; if you do not already have a copy handy, this is a particularly handsome edition to have.

Robert E. Pollack, Ph.D.
Columbia University, New York, NY 10027