>>The ancestor who could dive better had more children? Could feed his family better? I think so too. Also the deep diver got the most beautiful /youngest /he

>>The ancestor who could dive better had more children? Could feed his family better? I think so too. Also the deep diver got the most beautiful /youngest /healthiest bride who would in turn bear healthier children. Rinse, repeat, with the offspring who inherited same genes. Over 1000 years of the same, the population changes.