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A meme,
according to the by-now-standard dictionary definition, is “an element
of a culture or system of behavior that may be considered to be passed
from one individual to another by nongenetic means, especially imitation.”
The idea (a meme itself?) was first introduced by Richard Dawkins in
his 1976 book, The Selfish Gene. Dawkins’s intention was to
make the points that evolution by natural selection is not limited to
genes and that it isn’t an accident of life on Earth. Rather, Darwinian
principles are universal, and they apply to whatever other system features
the basic characteristics of heritable variation in attributes affecting
fitness.
But we
only know of one such system, life on Earth, and that system is inextricably
dependent on genes. Moreover, life on our planet probably evolved only
once, and it isn’t at all clear that such evolution was inevitable
or even highly probable. So how could Dawkins make the argument that
Darwinian principles are universal (without waiting for the discovery
of life on Mars)? Enter memetics. The basic concept is that there is,
in fact, at least one other class of “replicators” subjected to
natural selection: memes. Derived from direct analogy with genes (and
with a nice Greek root in the word mimema,
which means “that which is imitated”), they indicate that ideas,
or mental constructs, can be thought of as replicators competing for
space inside human minds.
Memes
have caught on in a limited way. The new term has made it into dictionaries,
and a small number of books and even a dedicated technical journal have
discussed all things memetic. And yet there is quite a bit that is rather
unconvincing about the whole idea. To begin with, unlike the case of
genes, there doesn’t seem to be any distinction between memes themselves
and the phenotypes they produce. Genes in some sense “encode” proteins,
and proteins have a variety of effects that indirectly contribute to
the fitness of the organism carrying those genes. In Dawkins’s own
terms, there is a distinction between “replicators” (the genes)
and “interactors” (the organisms themselves).
But, in
the case of memes, the replicating “unit,” for example, an annoying
tune that gets into your head, forcing you to whistle it, and thereby
gets stuck into somebody else’s head, is both replicator and interactor.
This isn’t necessarily a fatal problem, but it begins to point toward
a disanalogy between genes and memes. And it gets worse.
The second
problem with memes is that nobody seems to know what their physical
basis is. Genes are-roughly speaking-pieces of nucleic acids (DNA or
RNA), with known physical-chemical characteristics. But memes can be
instantiated equally well inside someone’s mind (where presumably
they correspond to specific patterns of neuronal firings), on a computer’s
hard drive, in a book, or on an iPod. While it is true that, for decades
after Gregor Mendel proposed the idea of genes, biologists didn’t
know what they were made of either, the likelihood of pinpointing a
physical makeup for memes is less likely because they seem to be a sort
of “diffuse” entity that can have many physical incarnations. Again,
this is disanalogous with genes.
As a result
of this ambiguity, it is pretty much impossible to tell what constitutes
a meme. The typical examples in literature vary from the above-mentioned
annoying tune to religion. The latter kind of meme is often referred
to as a “meme complex,” or “memeplex.” This is again supposed
to be analogous to the fact that sometimes groups of genes with a common
evolutionary history are found physically linked on a chromosome to
form gene complexes, with the complex (rather than individual) genes
being the target of natural selection. But the idea works for genes
because of their identifiable and stable physical nature. In the case
of memes, there is no way to tell what constitutes a memeplex, other
than the arbitrary interest of the researcher.
As if all of
the above were not cause for a pause, there is a further, more crucial problem
with the idea of memes: it is not predictive. Philosopher Karl Popper once said
that evolutionary theory is not a scientific theory but rather a “metaphysical
research program” (see “Thinking about Science,” September/October 2004). What
he meant was that it is nor possible to falsify or test the theory because it is
based on a circular definition:
it says that natural selection favors the survival (and reproduction)
of the fittest, but it then turns around and defines the fittest as
those who survive (and reproduce). Creationists are fond of this statement
by Popper, without realizing that the philosopher himself eventually
admitted that he was wrong. Popper had misunderstood the nature of evolutionary
theory, not having realized that there are independent ways of making
predictions about the fitness of organisms (based on our understanding
of the functional ecology of their characteristics). This breaks the
circle and makes evolutionary theory a standard scientific theory.
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Massimo
Pigliucci is a professor of evolutionary biology and philosophy at Stony
Brook University in New York, a fellow of the American Association for
the Advancement of Science, and the author of
Denying Evolution: Creationism, Scientism and the Nature of Science.
His essays can be found at www.rationallyspeaking.org . |
But Popper’s
objection remains valid for memetics: the only way to tell which memes
are going to be successful, which tunes are going to stick in your mind,
or which religions are going to become popular is by waiting and seeing
what happens. That is, memeticists completely lack a functional ecological
theory of memes. Without it, the whole enterprise is scientifically
empty.
Indeed,
memetics-at least for now-doesn’t seem to add anything to the standard
view of gene-culture co-evolution that was developed well before Dawkins
put down his ideas in The Selfish Gene.
Ideas clearly do evolve, and there is in fact a somewhat undeniable
analogy between memes and the evolution of genes. But we don’t need
to push that analogy too far, and we certainly don’t need a whole
new vocabulary to make sense of it.
Finally,
despite the questionability of memetics, Dawkins’s claim about universal
Darwinism is probably correct, and we do have a nonbiological example
to study at our leisure: computer scientists have discovered the idea
of “genetic” algorithms, i.e computer programs that can Iiterally
evolve by mutation and selection, perfectly mimicking the biological
process. Indeed, researchers in this field have independently rediscovered
many of the laws and generalizations that population geneticists have
produced ever since the beginning of modern genetics at the dawn of
the twentieth century.
Darwinism,
therefore, does seem to be a universal property of certain kinds of systems.
Memes, on the other hand, have a long way to go before becoming a sufficiently
fecund concept for scientists to work with. |
