Fig 1. Model timing.

a: Demes begin a generation with given technology and number of SI types. b: Interaction during a generation gives individual fitnesses and causes advances in deme technology (here, demes A and C increase their tech level). c: Some demes (here, deme B) face invasion by other demes (deme A). If the invading deme has higher technology, the invaded deme is eliminated and replaced by a replica of the invading deme (here, deme B is eliminated and replaced by deme D, a replica of deme A). d: Demes reproduce and populate the next generation via a finite population replicator dynamic (here, we see within-deme selection and genetic drift in demes A and D changing the number of SI types). e: Technology levels and number of SI types are carried forward into the next generation.