The Logic of Life: A History of Heredity
by François Jacob, translated by Betty E. Spillman
Pantheon, 348 pp., $8.95
After a century of tissue rejection, the grafting of Darwinian evolution theory into the body of French thought is at last proceeding with all deliberate speed. One says “deliberate” because even now very few true evolutionary biologists are to be found in either the universities or the medical schools of France. The paleontological and physiological traditions of Cuvier and Bernard are still influential among French academic biologists and medical scientists; and neither of these essentially structural modes of thought displays any great compatibility with Charles Darwin’s populational approach. Yet at the pinnacle of the scientific hierarchy, at the Institut Pasteur and the Collège de France, there is a small group of remarkable biologists who are at last determined to achieve a successful transplant, and to install within the Cartesian world picture of French science a functioning account of variation, natural selection, and the rest—ideas that have hitherto provoked in France the reactions proper to “foreign bodies.”
The two principal figures in this group are Jacques Monod and François Jacob, who are internationally known for their “operon” theory. This theory is designed to explain how the biochemical processes taking place along macromolecules in cell nuclei are switched on and off, and so to account for the puzzling latency and intermittence of gene action. For why are not all genes active all the time? The philosophical attitudes underlying their enterprise were first presented to a wider public a few years ago in Monod’s book Le Hasard et la Nécessité
Jacob’s book was well worth waiting for. It is an altogether more serious piece of work than Monod’s, more tightly argued, better organized, and less rhetorical: an admirable addition to the popular literature of French science. Where Monod put forward a lawyer’s brief, in which the crucial distinction between the intentional (teleological) activities of human beings and the mechanically self-correcting (teleonomic) processes of biology was deliberately obscured behind the common word projet, Jacob tells his story absolutely straight. As a result, it is possible to see at last exactly what is going on: i.e., how this improbable union of neo-Cartesian physiology and neo-Darwinian natural history is being effected.
To put the point in the kind of biological terms that Jacob himself appreciates, there was indeed no way of relating the population genetics on which neo-Darwinism rests—or even the chromosomal genetics of T.H. Morgan and his successors …