Living in a physical world

摘要

The diversity of life on earth dazzles all of us - the rich profusion of its designs, the wide size range of its organisms, the complexities of its hierarchical levels, and so forth. Undaunted, we life scientists seek broadly applicable rules, common patterns of organizations, and order beneath the perceptual chaos; we look for alternatives to the easy answers of revealed truth. Biology, no less than the physical sciences, treads this bumpy path - indeed the overt diversity of life puts especially bad bumps in its way. Perhaps its special difficulty underlies the gradual estrangement of biology from the more obviously successful physics of the post-Newtonian era and its awkward reintegration into the larger world of science in the twentieth century. That process remains incomplete; blame, if leveled, rests on the untidiness and distinctiveness of the subject. The tidy formulas of Newtonian physics work even less well for us than they do for, say, practicing engineers. Life directs its chemistry with sets of governing molecules and carries it out with the aid of catalysts of breathtaking specificity. And biology enjoys a strange organizing principle, evolution by natural selection, barely hinted at elsewhere in science.