"The rise of information theory aided and abetted a new view of life. The genetic code—no longer a mere metaphor—was being deciphered. Scientists spoke grandly of the biosphere : an entity composed of all the earth’s life-forms, teeming with information, replicating and evolving. And biologists, having absorbed the methods and vocabulary of communications science, went further to make their own contributions to the understanding of information itself.
Jacques Monod, the Parisian biologist who shared a Nobel Prize in 1965 for working out the role of messenger RNA in the transfer of genetic information, proposed an analogy: just as the biosphere stands above the world of nonliving matter, so an “abstract kingdom” rises above the biosphere. The denizens of this kingdom? Ideas.
‘Ideas have retained some of the properties of organisms,’ he wrote. ‘Like them, they tend to perpetuate their structure and to breed; they too can fuse, recombine, segregate their content; indeed they too can evolve, and in this evolution selection must surely play an important role.’
Ideas have ‘spreading power,’ he noted—‘infectivity, as it were’—and some more than others. An example of an infectious idea might be a religious ideology that gains sway over a large group of people. The American neurophysiologist Roger Sperry had put forward a similar notion several years earlier, arguing that ideas are ‘just as real’ as the neurons they inhabit. Ideas have power, he said:
Ideas cause ideas and help evolve new ideas. They interact with each other and with other mental forces in the same brain, in neighboring brains, and thanks to global communication, in far distant, foreign brains. And they also interact with the external surroundings to produce in toto a burstwise advance in evolution that is far beyond anything to hit the evolutionary scene yet.
Monod added, ‘I shall not hazard a theory of the selection of ideas.’ There was no need. Others were willing.
Dawkins made his own jump from the evolution of genes to the evolution of ideas. For him the starring role belongs to the replicator, and it scarcely matters whether replicators were made of nucleic acid. His rule is ‘All life evolves by the differential survival of replicating entities.’ Wherever there is life, there must be replicators. Perhaps on other worlds replicators could arise in a silicon-based chemistry—or in no chemistry at all.
What would it mean for a replicator to exist without chemistry? ‘I think that a new kind of replicator has recently emerged on this very planet,’ Dawkins proclaimed near the end of his first book, The Selfish Gene , in 1976. ‘It is staring us in the face. It is still in its infancy, still drifting clumsily about in its primeval soup, but already it is achieving evolutionary change at a rate that leaves the old gene panting far behind.’ That ‘soup’ is human culture; the vector of transmission is language, and the spawning ground is the brain.
For this bodiless replicator itself, Dawkins proposed a name. He called it the meme, and it became his most memorable invention, far more influential than his selfish genes or his later proselytizing against religiosity. ‘Memes propagate themselves in the meme pool by leaping from brain to brain via a process which, in the broad sense, can be called imitation,’ he wrote. They compete with one another for limited resources: brain time or bandwidth."