Information
Can there be a gene for altruism? Yes, says Dawkins, if this means “any gene that influences the development of nervous systems in such a way as to make them likely to behave altruistically.”♦ Such genes—these replicators, these survivors—know nothing about altruism and nothing about reading, of course. Whatever and wherever they are, their phenotypic effects matter only insofar as they help the genes propagate.
Molecular biology, in its signal achievement, had pinpointed the gene in a protein-encoding piece of DNA. This was the hardware definition. The software definition was older and fuzzier: the unit of heredity; the bearer of a phenotypic difference. With the two definitions uneasily coexisting, Dawkins looked past them both.
If genes are meant to be masters of survival, they can hardly be fragments of nucleic acid. Such things are fleeting. To say that a replicator manages to survive for eons is to define the replicator as all the copies considered as one. Thus the gene does not “grow senile,” Dawkins declared.
"It is no more likely to die when it is a million years old than when it is only a hundred. It leaps from body to body down the generations, manipulating body after body in its own way and for its own ends, abandoning a succession of mortal bodies before they sink in senility and death."
“What I am doing,” he says, “is emphasizing the potential near-immortality of a gene, in the form of copies, as its defining property.” This is where life breaks free from its material moorings. (Unless you already believed in the immortal soul.) The gene is not an information-carrying macromolecule. The gene is the information. The physicist Max Delbrück wrote in 1949, “Today the tendency is to say ‘genes are just molecules, or hereditary particles,’ and thus to do away with the abstractions.”♦ Now the abstractions returned.
Where, then, is any particular gene—say, the gene for long legs in humans? This is a little like asking where is Beethoven’s Piano Sonata in E minor. Is it in the original handwritten score? The printed sheet music? Any one performance—or perhaps the sum of all performances, historical and potential, real and imagined?
The quavers and crotchets inked on paper are not the music. Music is not a series of pressure waves sounding through the air; nor grooves etched in vinyl or pits burned in CDs; nor even the neuronal symphonies stirred up in the brain of the listener. The music is the information. Likewise, the base pairs of DNA are not genes. They encode genes. Genes themselves are made of bits.