Fraser Neiman 🇺🇸

Rob Boyd and Pete Richerson have made arguably the most significant augmentation to Darwinian evolution since Mendelian genetics. They identified and modelled a second stream of inheritance that's shaped our species: culture. I was surprised to learn they'd never done a joint interview before. Was an honour to be able to bring them together in San Francisco last week. Topics in the timestamps below. Links in the tweet below. Enjoy! Timestamps: (0:00:49) - How likely is it that cumulative cultural evolution actually began with australopithecines? (0:20:26) - By when was cumulative cultural evolution achieved among Homo? (0:23:31) - Rob and Pete explain (1) cultural evolution, (2) cumulative cultural evolution, and (3) gene-culture coevolution. (0:31:57) - "Culture, not natural selection, has been the main force shaping human genetic evolution for the last 1-2 million years." How do we know this? (0:37:00) - Examples of gene-culture coevolution. (0:43:05) - The chaotic climate of the Pleistocene (2.6 million - 11,700 years ago). (0:48:26) - How did Pete and Rob discover the climate was so variable in the Pleistocene? (0:51:51) - Culture was an adaptation to Pleistocene climate variation. (0:58:52) - How Pete and Rob came up with their explanation for how cultural brains evolved (an adaptation to climate variation). (1:02:16) - Increasing climate variation may actually have been driving brain size increases on Earth since the time of the dinosaurs 65 million years ago. (1:08:14) - Earth's climate variation was probably driven by its orbital perturbations, caused by Jupiter's gravitational pull. (1:13:34) - How contingent was the evolution of cultural brains? (1:22:46) - Has human brain size been shrinking over the last 10,000 years? (1:27:50) - Will technologies that obviate natural birth mean that human brain size (relieved of the constraint of the birth canal) resume their trend of large increases, or has cumulative culture reduced the selection pressure on brain size? (1:34:18) - How cultural evolution explains the fertility crisis. (1:43:19) - Which specific force of cultural evolution is the biggest cause of declining fertility? (2:02:13) - If global population peaks and then shrinks, say by mid century, how do we sustain a technologically advanced civilisation? (2:09:10) - Does Rob and Pete's understanding of how human intelligence evolved give them any unique insights into how artificial intelligence might be grown? (2:14:57) - How do Rob and Pete think about their partnership, and what makes scientific dyads so productive?