Doug Erwin talks to Jim about his book, The Cambrian Explosion: The Construction of Animal Biodiversity. They cover the unprecedentedly rapid evolution of life seen during the Cambrian explosion (approx 540 million BCE), archeological dating techniques & accuracy, micro-evolution vs macro-evolution, environmental potential, ecological opportunity and challenges, genetic/developmental contexts, continental landmass locations, pre-Cambrian multicellularity, ocean oxygen levels, snowball earth epoch, predation as an evolutionary driver, changes in species physical sizes, development of circulatory systems and neurons, brain evolution, niche construction & ecosystem engineering, evolutionary investment strategies, Cambrian taxonomic diversity, the Fermi paradox, and much more.