In proportion to our body mass, our brain is three times as large as that of our nearest relatives. This huge organ is dangerous and painful to give birth to, expensive to build and, in a resting human, uses about 20 per cent of the body's energy even though it is just 2 per cent of the body's weight. There must be some reason for all this evolutionary expense.

Memetics provides a new approach to the evolution of language in which we apply Darwinian thinking to two replicators, not one. On this theory, memetic selection, as well as genetic selection, does the work of creating language.

For the planet's sake, I hope we have bird flu or some other thing that will reduce the population, because otherwise we're doomed.

Finally, we might decide that civilisation itself is worth preserving. In that case we have to work out what to save and which people would be needed in a drastically reduced population - weighing the value of scientists and musicians against that of politicians, for example...

If everyone understood evolution, then the tyranny of religious memes would be weakened, and we little humans might find a better way to live in this pointless universe.

You start by copying other people's paintings or music or whatever. You get all of those skills before you branch out. Really creative people have a fantastic ability to copy things and then combine them in new ways. And whether we're talking about genes or memes, recombination is the real heart of creativity.

Certainly almost everything we do and think is colored in some way by memes, but it is important to realize that not everything we experience is a meme. If I walk down the street and see a tree, the basic perception that's going on is not memetic.