He doesn't explicitly mention Evolution but brings up the fact that day he was giving the speech is the Bicentennial of Charles Darwin's birth.
So because Darwin had a birthday, Obama believes in evolution?
I think you made one inference too many. Because he acknowledged Darwin's birthday does not mean he does believe in Evolution. Obama believes in Evolution is a statement you cannot possible backup, let alone know.
A fair question to ask might be why hasn't Obama had to answer this? Is it because he plants audience members to ask prescripted questions? Is it because he is afraid to answer real questions? Is he capable of answering a question honestly?
Walker answered a stupid question the best way he possibly could.
EDIT:
Damn you! Your new quote ruined me using your own quote against you!!!!!
Thanks for the quote.