Charles Darwin was not a great scientist in my opinion, which is why it's always odd to me that people see him as such a controversial and threatening figure. I believe in evolution...sort of (if you want to know some of my thoughts on the subject you can see it here).
Earlier, it was announced that a new biopic about Darwin starring Jennifer Connelly would not be released in the U.S. because no distributor wanted to touch it--they are too afraid of crazy Christians, who will no doubt flood any studio who has the guts to not censor the film with death treats and hate mail, and it just isn't worth the hassle.
So if you have an interest in Darwin in states, then I guess you'll have to bootleg. One day I hope people realize censorship never helps any one's cause--it only creates more interest.