Highlight: The Intertwined Evolution of Human Cognition and Autism

Fig. 1.Conceptual model illustrating the hypothesis of Starr and Fraser (2025): within a tissue, the evolvability of the different cell types is constrained by their relative abundances.Since gene expression changes in abundant cell types are more likely to result in a larger negative effect on fitness, these cell types should experience slower evolutionary rates when compared to rare cell types.In their study, the authors test this hypothesis by comparing gene expression profiles of neuronal cells in humans, nonhuman primates, and other mammals.Illustration provided by Starr and Fraser (2025).