I think I saw him with Sir Patrick Moore a few times? Very 'distingushed' in an old fashioned sort of way. Moore himself has done a great deal for astronomy, and is still on the ball. As for evolution, Attenborough is a great lecturer and educator. I have his whole series of books signed. Hawking is also a very good presenter but obviously he would be struggling with live debates.

Dave L

Moore:

Hawking:

Attenborough: