The most obvious implication of the survey seems to be that expert evolutionary biologists are strikingly less likely to be theists than are other Americans. Most are atheists or agnostics
True, but.... What do you think this proves really?
Could it be that theists are not inclined to get into a social circle that is dominated by the "other"? We see this all the time. Qualified conservatives are less likely to get jobs in academia because it is so dominated by liberals, so they are less likely to even try it. Mormons aren't likely to seek employment at theological seminaries, so they don't even bother.
Why are atheists less likely to engage in biblical scholarship? Many notable atheists do, actually, but on the whole, they are a tiny minority. It certainly isn't because studying the Bible leads more people to theism. Likewise, there is no reason to believe studying evolution leads to atheism.
Having said that, evolution study could easily result in the rejection of creationism. I suspect that those who are interested enough in the subject, already knew enough about it beforehand. In other words, they knew the Genesis story wasn't science before getting their Ph.D. So the program is attracting atheists, not creating them.