A small example of why I rate Dawkins as one of our greatest living thinkers and speakers

«Happenings are sometimes organised at which thousands of people hold hands and form a human chain, say from coast to coast of the United States, in aid of some cause or charity. Let us imagine setting one up along the equator, across the width of our home continent of Africa. It is a special kind of chain, involving parents and children, and we will have to play tricks with time in order to imagine it. You stand on the shore of the Indian Ocean in southern Somalia, facing north, and in your left hand you hold the right hand of your mother. In turn she holds the hand of her mother, your grandmother. Your grandmother holds her mother's hand, and so on. The chain wends its way up the beach, into the arid scrubland and westwards on towards the Kenya border.

«How far do we have to go until we reach our common ancestor with the chimpanzees? It is a surprisingly short way. Allowing one yard per person, we arrive at the ancestor we share with chimpanzees in under 300 miles.»

From Gaps in the Mind by Richard Dawkins, In PAOLA CAVALIERI & PETER SINGER (eds.), The Great Ape Project, New York: St. Martin's Griffin, 1993, pp. 81-87.

Go read it. The essay is only about 14 screensful.