We have the same genetic code for all living creatures. We have a large number of genes that are manifestly the same, but with detail differences - they look like different drafts of the same book. In extreme cases, like a human and a beetroot, it's like the difference between Matthew and Luke's Gospel - clearly they tell the same story, but with different words. Whereas with a human and a chimp, it's like two different printings of Matthew, with a few typos in one.

For centuries the most powerful argument for God's existence from the physical world was the so-called argument from design: Living things are so beautiful and elegant and so apparently purposeful, they could only have been made by an intelligent designer. But [Charles] Darwin provided a simpler explanation. His way is a gradual, incremental improvement starting from very simple beginnings and working up step by tiny incremental step to more complexity, more elegance, more adaptive perfection.

In our prehistoric past, we would have lived in extended families, surrounded by kin whose interests we might have wanted to promote because they shared our genes. Now we live in big cities. We are not among kin nor people who will ever reciprocate our good deeds. It doesn't matter. Just as people engaged in sex with contraception are not aware of being motivated by a drive to have babies, it doesn't cross our mind that the reason for do-gooding is based in the fact that our primitive ancestors lived in small groups.

If you look up at the Milky Way through the eyes of Carl Sagan, you get a feeling in your chest of something greater than yourself. And it is. But it's not supernatural.

Religious people split into three main groups when faced with science. I shall label them the "know-nothings", the "know-alls", and the "no-contests."

There are many religious points of view where the conservation of the world is just as important as it is to scientists.

People really, really hate their religion being criticized. It's as though you've said they had an ugly face; they seem to identify personally with it.