If you were to go to a business meeting, would you introduce yourself with "Hi, I'm Fester Chugabrew, the Christian"?
Would you put your religion on your business card? Not the cryptic inside baseball, fish symbol, but flat out say "member xyz church"?
Who knows the religion of these folks? But assuming they're all athiests isn't reasonable.
Although I wouldn't guarantee that in the future, as Christians are chasing scientists away from their churches as fast as they can. I suppose dumbing down congregations has the same bennefits for some church leaders as it does for liberals to dumb down schools.
Sure, people are entirely capable of hiding their beliefs. My point is, if you asked the folks who attended this world summit whether they believe God has anything to do with biology, I think you know what the answer would be.