EX is the ultimate absurdity. Forget the
hormonal rushes, the sweat and
contorted posturing. Forget about the
heartache, the flowers, the bad poems and the
costly divorce, just think about the biology. It’s
nuts. Cloning makes far more sense.
A clone, after all, just quietly gets on with
copying itself. And since every clone can
produce more clones, cloning produces far
more offspring. There is no need for males – a
waste of space, as hard-line feminists and
What’s more, each clone has a combination
of genes that has already been found fit for
purpose. Sex, by contrast, randomly mixes
genes into new and untested amalgams. And
the horrors of sex don’t end there. There is the
problem of finding a mate, and fighting off
rivals. Not to mention the risk of picking up
horrible diseases like AIDS and all sorts of
selfish replicators that exploit sex to spread
themselves through the genome.
All this made sex the “queen of evolutionary
problems” in the 20th century, taxing some of
the finest minds in biology. The issue isn’t just
explaining why almost all plants and animals
engage in sex. It is also explaining why the life
forms that ruled the planet for billions of years
and remain by far the most abundant – the
bacteria – manage fine without it.
That suggests that the ubiquity of sex
among complex organisms has something to
do with their ancient evolutionary history, not
just the recent more past. Could there be some
deep connection between the evolution of sex
and the evolution of complex cells more than
a billion years ago?
As you were probably taught at school, the
seemingly obvious answer to the question,
why bother with sex, is that sex generates
variation, the raw material for natural
selection. As environments change, sexual
species can therefore evolve and adapt faster.
In reality, though, most individuals live in
an environment very similar to that of
preceding generations. And if some start
reproducing by cloning, the clones – being
equally well adapted to the environment –
should rapidly drive the sexuals to extinction
by dint of producing far more offspring
competing for the same resources.
Sure, sex should be an advantage in the long
term, over thousands and millions of years,
but evolution doesn’t work like that. It doesn’t
plan ahead. And the environment rarely
changes enough in the short term, over years
and decades, to favour sex.
Not so fast, argued the great evolutionary
biologist Bill Hamilton. The environment that
really matters is on the inside, he said.
Parasites lynch us from within, and evolve so