Keynes is Darwin's great-great-grandson, and you can hear an interview with him on NPR's Fresh Air (from WHYY in Philadelphia) that aired yesterday. Just click that link to Fresh Air. I haven't seen the movie. Unfortunately, some of the early reviews aren't all that good. Here's the first paragraph of a compilation at moviefone:
It's survival of the fittest at the box office and unfortunately for the new Charles Darwin bio 'Creation,' the consensus is director Jon Amiel ('Copycat,' 'Entrapment') has not created a great work.