Fig. 11

Left: A common ancestor cycle. The top most vertex is a common ancestor of the lowest vertex. The horizontal red line is a marriage, all other lines are parent–children edges. Center: A union cycle, specifically the double cousin situation described in "Background: genealogical and social networks". The left-most and right-most vertices are parents of their neighboring vertices. The two horizontal red lines are marriage edges. Right: A \(\theta\)-cycle formed by a common ancestor cycle with two overlapping hybrid cycles