I don't really understand why Dawkins can't see his own presuppositions:
1. The Bible gives us rough information to pin down when the story of Noah happened. But it doesn't.
2. That the Flood story happened when the earth's continents look like they do today. How does he know that?
I'm not a young earth creationist and I don't believe the Bible was ever intended to give us the method of dating the flood or human creation. Dr. Dawkins thinks that the problem is that people literally read the Bible as True. What does the Bible actually say? Set side for a moment any question you might have about if it is true or not and think about what it says.
25 Two sons were born to Eber:
One was named Peleg, because in his time the earth was divided; his brother was named Joktan. - Genesis 10:25
What does this mean? Given that this passage is after the flood, how was the earth divided. I think everyone agrees that there was one continent and it split. When did this happen? Science allows us to have a good idea. The Bible tells us that the split after the flood. If there was only one continent prior to the flood and that there were fewer animal types on the earth then, why couldn't they all not only reach the ark, but also fit. For example only the ancestors of all domesticated dogs was on the ark. All the marsupial species in Australia did not have to be on the ark - just a few. I think that Dawkins definitely failed here.
Debunking Christianity: Richard Dawkins Debunks Noah's Ark