produce. I am, of course, talking about ‘the correlation of parts’, ‘developmental constraints’, ‘mutational bias’, the ‘integration of development with evolution’, ‘the real reason pigs can’t fly’ — every generation since Darwin has considered, and failed to solve, the problem, though they’ve usually given it a new name. The second question is rather like the first: can we predict the course of cultural evolution in the long term? (One might add: or even in the short term?) Darwin saw the analogy between cultural and organic evolution; theoretical population geneticists worked out the mathematics of the transmission of cultural traits years ago. Despite this, the field really didn’t take off. I think it is taking off now. Culture is the New World of evolutionary science. To be sure, anthropologists discovered it long ago, but rather like Vikings in America, they never made much of what they found.