We use the genomes of Neandertals and Denisovans, the closest evolutionary relatives of present-day humans, to identify genomic variants that are unique to modern humans. We introduce such variants that may influence metabolism, neuronal function and behavior into the genomes of cells and of mice to study their physiological consequences. We hope to learn how modern humans are unique and perhaps aspects of why we developed complex cultures and technology on a scale far exceeding our predecessors.
