First off, I haven't read any of Dawkin's books, and I don't even care that much for the man. The greath thing about atheism is that I don't have to worship anybody blindly.
Now, for the story behind this.
Short story: Ben Stein is a lying skidmark.
Long story:
Potholer54: "Golden Crocoduck nominees 2012 (Part 3)" - YouTube
If you don't feel like watching the video - you should, though; Potholer is a real funny guy, very genteel - basically, Ben Stein asked him if there were any circumstances where he could imagine that intelligent design was possiblle, and Dawkins responded with what you hear. The dishonesty comes in with how Stein edited the video - the question Stein asked was cut, so it looks like Dawkins is advocating for intelligent design by aliens. He's not. Stein gave him a hypothetical, and he answered it.
So, no, I hate to ruin that bulge in your pants, but Ben Stein doesn't believe that aliens seeded life on Earth, and he's not allowing for the possibility. Ben Stein edited the video to make him look like he's taking a position he doesn't hold.
But hey, I'm sure that's not a problem for you. What does it matter if you're misrepresenting someone's position, so long as it helps your cause, right? After all, it's not like you believe you're being watched by an all-powerful, omnibenevolent diety who warned you not to bear false witness.
Oh. Wait.