Check out why we are globetrotters: as previous research has shown, long alleles of the DRD4 gene have been linked to novelty-seeking personality, hyperactivity, and risk-taking behaviors … It can be argued reasonably that exploratory behaviors are adaptive in migratory societies… usually harsh, frequently changing, and always providing a multitude of novel stimuli and ongoing challenges to survival”
“The findings revealed a very strong association between the proportion of long alleles of the DRD4 gene in a population and its prehistorical macro-migration histories.”
Find the article here:
http://www.sciencedirect.com/science/article/pii/S109051389900015X