title: Modular structure facilitates mosaic evolution of the brain in chimpanzees and humans.
abstract: Different brain components can evolve in a coordinated manner or they can show divergent evolutionary trajectories according to a mosaic pattern of variation. Understanding the relationship between these brain evolutionary patterns, which are not mutually exclusive, can be informed by the examination of intraspecific variation. Our study evaluates patterns of brain anatomical covariation in chimpanzees and humans to infer their influence on brain evolution in the hominin clade. We show that chimpanzee and human brains have a modular structure that may have facilitated mosaic evolution from their last common ancestor. Spatially adjacent regions covary with one another to the strongest degree and separated regions are more independent from each other, which might be related to a predominance of local association connectivity. Despite the undoubted importance of developmental and functional factors in determining brain morphology, we find that these constraints are subordinate to the primary effect of local spatial interactions.
authors.affiliation: Department of Anthropology, The George Washington University, Washington, District of Colombia 20052, USA.
authors.forename: Aida
authors.initials: A
authors.lastname: Gómez-Robles
authors.affiliation: 1] Neuroscience Institute, Georgia State University, Atlanta, Georgia 30302, USA [2] Division of Developmental and Cognitive Neuroscience, Yerkes National Primate Research Center, Atlanta, Georgia 30322, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Hopkins
authors.affiliation: Department of Anthropology, The George Washington University, Washington, District of Colombia 20052, USA.
authors.forename: Chet C
authors.initials: CC
authors.lastname: Sherwood
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D005075:Biological Evolution; D001921:Brain / Q000033:anatomy & histology*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D002679:Pan troglodytes / Q000033:anatomy & histology* / Q000502:physiology; D055815:Young Adult