Preprint: genome-wide study maps polygenic basis of human brain globularity and links it to evolutionary selection

A preprint posted to bioRxiv reports a genome-wide association study (GWAS) of brain globularity — the rounded, high-vaulted skull shape that distinguishes modern Homo sapiens from earlier hominins — using paired genetic and MRI-derived brain-shape measurements from 34,595 adults of European ancestry.

The authors identify genetic variants associated with globularity and embed these findings within analyses of genetic variation under recent natural selection and evolutionary constraint. The study frames globularity as a tractable phenotype for investigating the genetic underpinnings of traits that may be unique to our species, and the authors explore possible associations between brain morphology and cognitive traits that are candidates for being distinctively human.

The work is relevant to researchers in human evolutionary genetics, neurogenomics, and cognitive genomics. The ancestry composition of the study sample (predominantly European) is a limitation the authors note, and the preprint describes associations rather than causal mechanisms. As with all large imaging-genetic studies, the effect sizes of individual variants are small and the findings describe population-level patterns rather than individual-level predictions.

This is a preprint and has not yet been peer-reviewed.