Is Biological Life More than Coded Molecules? - Review

The Triple Helix. By Richard Lewontin. Harvard University Press, Cambridge/London, 2000. ISBN 0-674-00159-1. 136 pp. Hardback, $22.95.

The war of books continues to rage in the north Atlantic over an old question: What exactly is biological life? Harvard and Oxford are fighting at the front.

Richard Lewontin, Harvard's eminent Agassiz Research Professor in Comparative Biology, is not pleased with those too preoccupied with the operations of genes. "No developmental biologist asks why human beings and chimpanzees look so different, except to say the obvious: that they have different genes." Lewontin thinks there's much more to life than that.

His new book, The Triple Helix, is a jab at molecular biology and genetics, and a conspicuous swipe at Richard Dawkins, the Oxford agitator for selfish genes and extended phenotypes. Dawkins, in his contrary books, asks instead why humans and chimpanzees look so much alike. The base reductionism he uses offends Lewontin. Besides, it was Dawkins, in his Unweaving the Rainbow (1998, reviewed in SKEPTICAL INQUIRER, March/April 1999), who previously kicked the academic pants of Harvard's biologist Stephen Jay Gould. Now it's Lewontin's turn to kick back for Gould's sake, and Harvard's, too.

Lewontin abstains from mentioning either his colleague or his adversary, but he is out to make a case against biologists who are "... devoted to explanations of the way in which a reductionist approach to the study of living organisms can lead us to formulate incomplete answers to questions about biology or to miss the essential features of biological processes or to ask the wrong questions in the first place."

More than naked reductionism, Lewontin believes, is needed to explain life and how it evolves--something more than codes written on DNA or their transcriptions onto microchips must emerge to offer us epistemological relief: "If we had the complete DNA sequence of an organism and unlimited computational power, we could not compute the organism because the organism does not compute itself from its genes."

Lewontin, in his concise attack, makes clear that the war between holism and reductionism in science is not over. He believes geneticists and their molecular explanations of life have "... pauperized, temporarily it is to be hoped, an entire field of study." Money and respect are the main reasons why Harvard and Oxford continue to lob their literary ordnance at each other. Lewontin sides with his wounded colleague, Gould, noted punctuator of evolution and authority on the Cambrian explosion (when the body plans of animals were established rather suddenly about half a billion years ago). Dawkins, with his body-snatching genes and mind-snatching memes, is bothering these Harvard laureates again.

Here, precisely, is where biology is coming to terms with itself. Both sides of this epic drama are concerned with the validity of emergent properties, like gravity, governed by physical laws. Molecular biologists can show with astonishing clarity how genes manifestly build, operate, repair, reproduce, and even kill living organisms. Indeed genetic dogma defines the new emergent property, and old-timers like Lewontin are not so impressed.

He sees a different sort of emergent property--a "dialectic." He uses interesting examples in both plant and animal kindngdoms to show that biological things do appear to happen apart from genes: environmental influences on corn yield, morphological changes in tropical vines, different eye sizes in fruit flies, skeletal traits in dinosaurs. All of these lead him to understand life as a recursively "dialectic" phenomenon in nature. The third strand of "the triple helix" is taken to mean "... a dialectic between organisms and their environments, each forming the other." As such, Lewontin believes that holistically correct biologists should focus on "... a dialectic of method and problematic in science.

Lewonrin complains about the tedium of mechanical reductionism where "[t]he problem of how to parse the world into appropriate bits and pieces is a consequence of the analytic tradition that modern science has inherited from the seventeenth century" This distinguished biologist feels a natural need to refute reductionism because life seems so much more complex.

If the chemists have all the answers, then what's a biologist to do?

A reader might also ask why Lewontin does not place his own hypothesis mote squarely on the table. He offers no parameters for measuring the "dialectic." Instead, he drags out vague promises of what he calls the "Three C's": catastrophe theory (an ocean wave breaking), chaos theory (a hurricane forming), and complexity theory (undiscovered laws of complex systems). Lewontin can only hope, however, because none of these theories has yet revealed a single emergent property to match the power of a geneticist's Hardy-Weinberg equation (the statistical distribution of alleles), homeobox genes (an organism's developmental software), the genetic dictionary (the exact code), or the Central Dogma (that coded information on DNA must always flow through RNA to make a protein, and never in the opposite direction).