ABSTRACT
Is there anything that modern biology can tell us about the nature of Homo sapiens? When I was a boy, my aunt sang, “Ah, sweet mystery of life, at last I’ve found you,” but she was a bit premature. Not until 1943 did Avery find out what genes are made of. He was able to turn one kind of bacterium into another by removing its DNA and substituting that of another strain. A decade later, Crick and Watson showed that the atoms of DNA are arranged in a double-helical structure which determines how that substance works. So it came to be known that strands of deoxyribonucleic acid molecules contain all the information necessary to make everything that is alive. DNA possesses the astonishing chemical prop erty of replication: it makes exact copies of itself by serving as a template along which the appropriate constituents of new helical strands line up in the exactly correct order. This is accomplished with the assistance of catalysts that do the joining. The order is the information, just as the order of the letters in this sentence is the information.
