Socio-cultural selection and the sculpting of the human genome: Cultures’ directional forces on evolution and development

This paper argues for culture as a significant determinant of the modern human genome. As progress in the fields of genetics and evolutionary biology have gained greater insights into evolutionary process, aspects of classical proposals explaining how phenotypic responses to environmental experience could make their way into the genotype have returned in new guises. Recent proposals recognize environmental context as a key source of genetic variation by directly altering selection pressures to mask and unmask adaptive value of expressed traits, by reorganizing the combination and expression of genes during ontogeny to provide novel variants for selection, and by influencing developmental trajectories through epigenetic systems acutely sensitive to ontogenetic contexts. The emergence of a robust human socio-cultural niche, shielding humans from more proximate evolutionary pressures that marked our ancestral evolution, has arguably provided the strongest directive force on modern human evolution. Language is discussed as an exemplar of a cultural niche with a powerful self-organizing dynamic and the potential to dramatically alter the human genome.