- seCtIon FoUR: eVoLUtIon
2013). Epigenetic effects do not actually change any genes but involve heritable
changes in the way genes are expressed, including switching them on and off.
Yet the basic distinction between germ line and soma remains, and there are
good reasons for evolution to work this way. Most things that happen to pheno-
types are harmful, such as failures in development, damage of various kinds, and
ageing. If all these changes were passed on, useful developments in design would
be lost. Also, most phenotypes are just not very successful, so it makes sense to
go ‘back to the drawing board’ in each generation (Dawkins, 1989). Another way
of putting it is that schemes which copy the instructions for making a product
(such as making organisms from instructions in the DNA, or building cars on a
production line) are better than schemes that copy the product itself because of
the inevitable errors introduced by imperfect copying (Blackmore, 1999).
By the early twentieth century, Darwinism was in the doldrums, but change came
in the 1930s with the discovery of the basis of genetics and its integration with
natural selection in ‘the modern synthesis’. The resulting neo-Darwinism explained
why no directing force was needed; natural selection working on variation cre-
ated by the recombination and mutation of genes was sufficient. Clearly other
processes such as genetic drift, gene flow, random events, epigenetic inheritance,
and self-organising principles play a role in evolution, and there have been fierce
arguments over their relative contributions (R. Dawkins, 1986; Dennett, 1995b;
Gould and Lewontin, 1979; Jablonka, Lamb, and Zeligowski, 2005; Johnson and
Lam, 2010). Even so, there is no hint of a guiding force in evolution and no evi-
dence to suggest that mind or consciousness plays that role.SELFISH REPLICATORS
Who or what is evolution for? Who or what is the ultimate beneficiary of eyes,
wings, brains, and digestive systems? Darwinism is frequently misunderstood
as a mechanism that creates adaptations ‘for the good of the species’. A simple
example will show why it is not.
Imagine a population of rats successfully living off human rubbish in a huge
modern city – let’s say London. Outside every shop and restaurant are plenty of
dustbins that contain plenty of nice rat food. Every night when the workers leave,
there is a chance that the dustbins will not be properly sealed, or food will be left
on the ground. As long as the rats wait quietly until the humans have left, they
will have it all to themselves. The best strategy ‘for the good of the species’ is for
every rat to wait, but will they? Of course not. If just one rat has genes that incline
it to jump in first, causing the dustbin lid to clatter to the ground and the humans
to come running to close it, that rat will still be better off than the rest, running
off with some nice rotting meat or a soggy sandwich. That rat will get fatter, take
more food home, and produce more offspring, who will also tend to inherit the
‘jump first’ tendency. The patient rats lose out. Note that this general point is not
a recipe for unadulterated selfishness. There are many reasons why cooperative
and altruistic behaviours can thrive alongside selfish ones (Matt Ridley, 1996;
Fletcher and Doebeli, 2009; Nowak and Highfield, 2011). It is, however, an argu-
ment against evolution proceeding ‘for the good of the species’. We must not,
therefore, fall into the error of thinking that consciousness could have evolved
because it was good for our species, or indeed for any other species.