Two of the chullpas contained sets of males with identical Y chromosomes, which meant these were two groups of directly related males (fathers, sons, brothers) of several generations buried together.This finding matched the currently accepted male-dominated ayllu theory.
There was an outlier, though. In a third chullpa three different male lineages were found. Comparison of the maternal DNA of these males suggests that two of the males had the same mother but different fathers, and the third male was related to one of the mothers (but not the fathers), probably a half brother.
Story: Jennifer Welsh, LiveScience | Photo: M. Baca et. al, BMC Genetics, 2012