As The Selfish Gene notches up 40 years in print, BBC News asked Richard Dawkins whether his most famous book is relevant today (answer: yes), whether he has any regrets about public spats over religion (no), and whether he is quitting Twitter (sort of).
"I'd so much rather talk about this than about politics."
This, from a thinker most famous as a fearless firebrand, sounds rather incongruous. But as Prof Dawkins hunches over his laptop to dig up examples of biomorphs - the computer-generated "creatures" he conceived in the 1980s to illustrate artificial selection - it is transparently, genuinely felt.
Later, we touch on the fact that he sees public debate as a scientist's responsibility. Right now, he wants to talk about molluscs.