richard_dawkins_-_the_god_delusion

192 T H E G O D D E L U S I O N
In the world of genes, the occasional flaws in replication
(mutations) see to it that the gene pool contains alternative variants
of any given gene - 'alleles' - which may therefore be seen as competing
with each other. Competing for what? For the particular
chromosomal slot or 'locus' that belongs to that set of alleles. And
how do they compete? Not by direct molecule-to-molecule combat
but by proxy. The proxies are their 'phenotypic traits' - things like
leg length or fur colour: manifestations of genes fleshed out as
anatomy, physiology, biochemistry or behaviour. A gene's fate is
normally bound up with the bodies in which it successively sits. To
the extent that it influences those bodies, it affects its own chances
of surviving in the gene pool. As the generations go by, genes
increase or decrease in frequency in the gene pool by virtue of their
phenotypic proxies.
Might the same be true of memes? One respect in which they are
not like genes is that there is nothing obviously corresponding to
chromosomes or loci or alleles or sexual recombination. The meme
pool is less structured and less organized than the gene pool.
Nevertheless, it is not obviously silly to speak of a meme pool, in
which particular memes might have a 'frequency' which can change
as a consequence of competitive interactions with alternative
memes.
Some people have objected to memetic explanations, on various
grounds that usually stem from the fact that memes are not entirely
like genes. The exact physical nature of a gene is now known (it is
a sequence of DNA) whereas that of memes is not, and different
memeticists confuse one another by switching from one physical
medium to another. Do memes exist only in brains? Or is every
paper copy and electronic copy of, say, a particular limerick also
entitled to be called a meme? Then again, genes replicate with very
high fidelity, whereas, if memes replicate at all, don't they do so
with low accuracy?
These alleged problems of memes are exaggerated. The most
important objection is the allegation that memes are copied with
insufficiently high fidelity to function as Darwinian replicators. The
suspicion is that if the 'mutation rate' in every generation is high,
the meme will mutate itself out of existence before Darwinian
selection can have an impact on its frequency in the meme pool. But