Evolution of Family Names in China

ScienceDaily has an interesting short article about a study of the evolution of family names across China.  The study, which was published in American Journal of Physical Anthropology, was conducted by Chinese researchers.  One statistic mentioned is that 100 family names account for 85% of the population.  A key assumption that seems to have been made, or at least that is not accounted for in this article, is that people did not change their names.