We are all cousins

I'm reading the second volume of Richard Dawkins' authobiography ("Brief Candle in the Dark") without having read the first one. My apologies for this lack of reading discipline. Well, actually, to be honest I bought it today in the science museum of Barcelona ("Cosmocaixa"), which offers the best combination in town of restaurant and bookshop. This famous scientist links many anecdotes using the sequence of his experiences as an academic and writer. Explaining how he interviewed prospective students at Oxford, he says: "Another favourite question to test their biographical intuition began: How many grandparents do you have? Four. And how many great-grandparents? Eight. And how many great-great-grandparents? Sixteen. How many ancestors do you think you had two thousand years ago, in the time of Christ? The brighter ones tumbled to the fact that you can't go on doubling up indefenitely, because the number of ancestors rapidly overtakes the billions of people in the world now, let alone the number that were alive in the time of Christ. That proved to be a good line of reasoning to coax them to the conclusion that we are all cousins, with numerous shared ancestors who lived not so long ago." This paragraph, together with the one where he calls the double college and department system at Oxford and Cambridge a "federal university" suggests that the famous atheist Dawkins is right in at least two lines of thought. Having said this, I will keep The Guardian's ironic book review in mind while reading the rest of the book.