Genes 2 Brains 2 Mind 2 Me

Comparisons of human genome variation within and across closely related species have great potential to reveal ways in which the brain and mind of modern humans may or may not have differed from our hominid ancestors. Such comparisons have recently revealed a great many genomic targets of natural selection, some of which are expressed in the developing brain, and, hence, might provide clues to the mental life of our ancestors. Variation in two such candidates ASPM (rs964201) and MCPH1 (rs2442496) arose approximately 50,000 years ago and show strong positive selection in the lineage leading to humans. What do these genes and common variants do ? Do they affect language acquisition ? Social behavior ? Intelligence ? Any type of process that might smack of something uniquely ‘human’ ? In their paper [DOI], “Investigation of MCPH1 G37995C and ASPM A44871G polymorphisms and brain size in a healthy cohort“, Dobson-Stone et al., used structural MRI to determine whether differences in whole brain volume or grey matter volume might relate to either or both of these variants. Although no evidence was found that relate these common variants (rare mutations can cause microcephaly) their methodological approach seems like a fantastic strategy for gaining insights into our human origins.