People write to me that evolution is only a theory. Well, it is not a theory. Evolution is as solid a historical fact as you could conceive. Evidence from every quarter. What is a theory is whether natural selection is the mechanism and the only mechanism. That is a theory. But the historical reality that dinosaurs led to birds and mammals produced whales, that’s not theory.
Sir David Attenborough
Charles Darwin and the Tree of Life, BBC One, 9pm, Sunday, February 1