Darwin's Dangerous Idea - Evolution and the Meaning of Life

344 THE CRANES OF CULTURE
These new replicators are, roughly, ideas. Not the "simple ideas" of Locke
and Hume (the idea of red, or the idea of round or hot or cold ), but the sort
of complex ideas that form themselves into distinct memorable units— such
as the ideas of
arch
wheel
wearing clothes
vendetta
right triangle
alphabet
calendar
the Odyssey
calculus
chess
perspective drawing
evolution by natural selection
impressionism
"Greensleeves"
deconstructionism
Intuitively, we see these as more or less identifiable cultural units, but we
can say something more precise about how we draw the boundaries—about
why D-F#-A isn't a unit, and the theme from the slow movement of Beethoven's
Seventh Symphony is: the units are the smallest elements that replicate
themselves with reliability and fecundity. We can compare them, in this
regard, to genes and their components: C-G-A, a single codon of DNA, is
"too small" to be a gene. It is one of the codes for the amino acid arginine,
and it copies itself prodigiously wherever it appears in genomes, but its
effects are not "individual" enough to count as a gene. A three-nucleotide
phrase does not count as a gene for the same reason that you can't copyright a
three-note musical phrase: it is not enough to make a melody. But there is no
"principled" lower limit on the length of a sequence that might come to be
considered a gene or a meme (Dawkins 1982, pp. 89ff )• The first four notes
of Beethoven's Fifth Symphony are clearly a meme, replicating all by
themselves, detached from the rest of the symphony, but keeping intact a
certain identity of effect (a phenotypic effect), and hence thriving in contexts
in which Beethoven and his works are unknown. Dawkins explains how he
coined the name he gave these units:
... a unit of cultural transmission, or a unit of imitation. 'Mimeme' comes
from a suitable Greek root, but I want a monosyllable that sounds a bit like
'gene'....It could alternatively be thought of as being related to 'memory'
or to the French word meme___
Invasion of the Body-Snatchers 345
Examples of memes are tunes, ideas, catch-phrases, clothes fashions,
ways of making pots or of building arches. Just as genes propagate themselves
in the gene pool by leaping from body to body via sperm or eggs, so
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. If a
scientist hears, or reads about, a good idea, he passes it on to his colleagues
and students. He mentions it in his articles and his lectures. If the idea
catches on, it can be said to propagate itself, spreading from brain to brain.
[Dawkins 1976, p. 206.]
Meme evolution is not just analogous to biological or genie evolution,
according to Dawkins. It is not just a process that can be metaphorically
described in these evolutionary idioms, but a phenomenon that obeys the
laws of natural selection quite exactly. The theory of evolution by natural
selection is neutral, he suggests, regarding the differences between memes
and genes; these are just different kinds of replicators evolving in different
media at different rates. And just as the genes for animals could not come
into existence on this planet until the evolution of plants had paved the way
(creating the oxygen-rich atmosphere and ready supply of convertible nutrients
), so the evolution of memes could not get started until the evolution
of animals had paved the way by creating a species—Homo sapiens—with
brains that could provide shelter, and habits of communication that could
provide transmission media, for memes.
There is no denying that there is cultural evolution, in the Darwin-neutral
sense that cultures change over time, accumulating and losing features, while
also maintaining features from earlier ages. The history of the idea of, say,
crucifixion, or of a dome on squinches, or powered flight, is undeniably a
history of transmission through various nongenetic media of a family of
variations on a central theme. But whether such evolution is weakly or
strongly analogous to, or parallel to, genetic evolution, the process that
Darwinian theory explains so well, is an open question. In fact, it is many
open questions. At one extreme, we may imagine, it could turn out that
cultural evolution recapitulates all the features of genetic evolution: not only
are there gene analogues (memes), but there are strict analogues of
phenotypes, genotypes, sexual reproduction, sexual selection, DNA, RNA,
codons, allopatric speciation, demes, genomic imprinting, and so forth—the
whole edifice of biological theory perfectly mirrored in the medium of
culture. You thought DNA-splicing was a scary technology? Wait till they
start making meme implants in their laboratories! Not likely. At the other
extreme, cultural evolution could be discovered to operate according to
entirely different principles ( as Gould suggests ), so that there was no help at
all to be found amid the concepts of biology. This is surely what many
humanists and social scientists fervently hope—but it is also highly unlikely,