Science is, as we have seen, all about generalizing. So my title refers to the return of ‘the organism’ in a general rather than a specific sense. And it refers to a return to what I consider to be its proper, central, place in the theory of evolution. We have already examined its initial displacement back in the 1930s. Now we need to take on the challenge of its replacement to a centre-stage position in the twenty-first century. This challenge involves correcting the situation that has arisen in which the gene and the population have, whether by design or by accident, combined to squash the organism out of evolution theory's core.

Let's begin with the ‘selfish gene’ concept, as championed by the Oxford-based biologist Richard Dawkins. My feeling about this concept is that it is useful in one specific way but that its importance has been vastly overstated. Its usefulness arises from its ability to quash the naïve notion that evolution necessarily works ‘for the good of the species’. Sometimes it does, sometimes not. It all depends on whether the interests of the species and the consequences of selection on organisms and families coincide. My favourite example of non-coincidence is this. A population of flies is growing rapidly because every adult female produces 200 eggs that, after larval mortality, become 20 adults. It is in danger of running out of resources several generations hence and thus becoming extinct. It would be beneficial to the population, and the species, if a mutant fly that appeared and was characterized by a reduced fecundity of 20 eggs could spread through the population so that all flies were of that kind.