For forty days and forty nights the law was on her side
To measure the degree of relatedness between populations, we used genetic distance. […] Genetic distance is like a molecular clock – it measures average separation times between populations. […] Our hypothesis is that, at a later stage, when populations enter into contact with each other, differences in cultural traits create barriers to exchange, communication, and imitation. […]
Our model implies that after a major innovation, such as the Industrial Revolution, the effect of genealogical distance should be pronounced, but that it should decline as more and more societies adopt the innovations of the technological frontier.
