Have you noticed that atheists spend a lot of time analysing and criticising - and engaging in conversation about God, whom they say doesn't exist!
Add in genes and rational thought and it makes for an interesting dialogue.
Bill Meuhlenberg has an insightful article about this, called 'More Atheist Tirades' - commenting on another article in The Age by Catherine Deveney.

More Atheist Tirades
Bill Meuhlenberg, 4 September 2009.
In one of the more bizarre ways to seek to explain away the universal phenomena of religion, some atheists have invented the idea that a god gene exists. Yes, there is no God, but we have a gene that makes us want to believe there is.

They do this of course for at least two reasons: to discount the overwhelming longing for transcendence found among mankind, and to discredit those who are believers. After all, if we believe in God simply because there is some gene or meme that makes us do so, then there obviously are no good, solid rational reasons for doing so.

Of course two can play this game. It makes as much sense to argue there are no rational arguments for atheism. Instead, we simply have an atheism gene which forces some people to adhere to atheism.  Indeed, in a totally materialistic world, our genes end up explaining – and causing – everything we do, believe or value. We are simply the product of our genes.

This is simply one oddity of atheism. Indeed, atheists are a strange bunch. They spend large hunks of their adult lives getting all hot and bothered about someone they claim does not exist. They spend zillions of hours informing us how lousy, bad, twisted, putrid and rotten God is. . .
Read the full article on Bill's website.