Primate brains vary in size and organization, but the genetic, developmental, and cellular basis for these differences has been difficult to study due to limited experimental models. In this talk, I will describe three complementary approaches for studying human-specific gene network evolution in conserved cell types using stem cell derived models and genome engineering. Ultimately, functional studies in great ape stem cell models, complemented by comparisons and validation in available primary tissue, could be applied beyond studies of progenitor cell evolution to decode the genetic and developmental origin of recent changes in cellular organization, connectivity patterns, myelination, and synaptic activity that have been implicated in human cognition.