Richard Dawkins

I like the phrase ‘History written all over us’. When we get cold, we get goosebumps. That’s because our ancestors were hairy. When they got cold, each hair rose to thicken the layer of air trapped by the hairs that would keep us warm. Like putting on another sweater. We are no longer hairy all over our bodies. But the little hair-erecting muscles are still there. And they still – uselessly – respond to cold by raising non-existent hairs. Our hairy history is written all over our bare skin. Written in goosebumps.

At the same time as he designed the cheetah to kill gazelles, he was busy designing the gazelle to be expert at escaping from cheetahs. He made both fast, so each could thwart the speed of the other. You can’t help wondering, whose side is God on? He seems to be piling on the agony for both. Does he enjoy the spectator sport? Wouldn’t it be horrible to think that God enjoys watching a terrified gazelle running for its life, then being knocked over and throttled by a cheetah gripping its throat so tightly that it can’t breathe? Or that he likes watching a cheetah that fails to kill starve slowly to death, along with its pathetically whimpering cubs?

Evolution consists of changes in the proportions of genes in populations. What we see from outside is changes in bodies or behaviour as the generations go by. But what is really going on is that some genes are becoming more numerous in the population and others less numerous. Genes survive, or fail to survive, in the population as a direct result of their effects on bodies and behaviour, only some of which are visible to us. It’s not just cheetahs and gazelles, zebras and lions; it’s chameleons and squids, kangaroos and kakapos, buffaloes and butterflies, beech trees and bacteria, every animal and plant, every mushroom and every microbe – they all contain the genes that
helped an unbroken line of ancestors to survive and pass those genes on.

We agreed that an eye or any organ that’s complicated (like Paley’s watch) is too improbable to have just happened (like Paley’s stone). An excellent seeing device like a human eye cannot spring spontaneously into existence. That would be too improbable, like throwing a hundred pennies down and getting all heads. But an excellent eye can come from a random change to a slightly less excellent eye. And that slightly less good eye can come from an even less good eye. And so on back to a really rather poor eye. Even a very, very poor eye is better than no eye at all. You can tell the difference between night and day, and perhaps detect the looming shadow of a predator. And the same kind of thing is true not just of eyes but of legs and hearts and tongues and feathers and blood and hair and leaves. Everything about living creatures, no matter how complicated, no matter how improbable – as improbable as Paley’s watch – can now be understood. Whatever it is that you’re looking at, it didn’t spring into existence all at once. Instead, it came from something just a little bit different from what went before. Improbability dissolves away when you see it as arriving gradually , stealthily, step by tiny step, where each step brings about only a really small change.
And the first step may not have brought about anything very good at all.

A great scientist – and larger-than-life character – of the twentieth century, J. B. S. Haldane, was once giving a public lecture. Afterwards, a lady stood up and said something like this:

‘Professor Haldane, even given the billions of years that you say were available for evolution, I simply cannot believe it is possible to go from a single cell to a complicated human body, with its trillions of cells organized into bones and muscles and nerves, a heart that pumps without ceasing for decades, miles and miles of blood vessels and kidney tubules, and a brain capable of thinking and talking and feeling.’

Haldane gave a wonderful reply: ‘But madam, you did it yourself. And it only took you nine months.’

we are likely to mistake a shadow for a burglar; we are unlikely to mistake a burglar for a shadow. We have a bias towards seeing agents, even when there aren’t any. And religion is all about seeing agency all around us.

Useless or superstitious beliefs, like the need to pray five times a day, or the need to sacrifice a goat to cure malaria, get passed on as a byproduct of sensible beliefs – or rather, as a byproduct of child brains being shaped by natural selection to believe parents, teachers, priests and other elders. And that is favoured by natural selection, because much of what elders tell children is sensible.

it’s safe to say you’ve drunk some of Julius Caesar’s pee.

Suppose two nations have different religions. One has a warlike god, like Yahweh/Allah. Or
like the warlike gods of the Vikings. The priests of such gods preach the virtues of courage in battle. They teach, perhaps, that a warrior who dies a martyr’s death will go straight to a special martyrs’ heaven. Or will go straight to Valhalla. They might even promise beautiful virgins in heaven to those men who die fighting for the tribal god (do you, like me, feel sorry for the poor virgins?). The other nation has a peaceful god or gods. Their priests don’t advocate war. They don’t preach heavenly bliss for those who die fighting. Maybe they don’t preach any kind of heaven at all. All other things being equal, which nation will have the bravest warriors? Which nation is more likely to conquer the other? And therefore, which of the two religions is most likely to spread? The question answers itself. It is a matter of history that the spread of Islam, from Arabia throughout the Middle East and the Indian subcontinent, was due to military conquest. And the same goes for the spread of Christianity by the Spanish conquerors in South and Central America