On the other hand, one could draw up an extremely long list of examples of people appealing to religion to justify immoral behaviour, from slavery and racism to suicide bombings and genocide. This kind of exercise proves little, though.

A better way of assessing the effects of embracing evolution is to compare countries with different levels of acceptance. Countries where higher numbers of people accept evolution have lower rates of murders, sexually transmitted diseases, teenage pregnancies and so on. In fact, more secular societies are healthier in almost every regard, one 2005 study (pdf) concluded.

This kind of crude correlation does not prove accepting evolution actually promotes moral behaviour, nor that religion promotes immoral behaviour. Indeed, other studies suggest the issue is far more complex.

But it does prove accepting evolution does not immediately lead to the breakdown of society, as some creationists claim.

Those who dismiss evolution as immoral often assume that religion is crucial to morality. As in: “People who believe in evolution have no basis for a moral code, other than the preeminent concern to pass on one’s genetic inheritance.”

In fact, there is growing evidence that we have an innate moral sense – that morality is something that evolved, in other words. This may seem surprising to those for whom the phrase “survival of the fittest” conjures up images of lions ripping each other to shreds and stags clashing antlers. But “the fittest” can mean the cleverest, the sneakiest, the best camouflaged, the least aggressive, the most attractive – or the least selfish.

Natural selection can favour altruism and fair play in certain circumstances. Behaviours such as loyalty to kin, intolerance of theft and punishment of cheats – the roots of morality – can be seen in many of our primate cousins.