Extended Data Fig. 2: Estimation of biological relatedness for Fujia individuals.

A, Pairwise differences (P0) calculated using the READ and plotted for both inter- and intra-cemetery comparisons. A dashed line represents the threshold for unrelatedness, determined by the median value from all pairwise comparisons, including inter-cemetery groups (Fujia_N, n = 105 pairs; Fujia_S, n = 1035 pairs) and intra-cemetery group (Fujia_N/S, n = 690 pairs). This line represents the normalization baseline and establishes cutoffs for classifying degrees of relatedness into second-degree, first-degree, and identical categories. B, The ternary plot of KIN results depicting the IBD sharing probabilities among paired individuals. The parameters k₀, k₁, and k₂ indicate the probabilities of sharing zero, one, or two chromosomes IBD at any given locus, respectively. This plot facilitates the identification of various kinship levels, including parent-child, sibling, second-degree, and third-degree relationships, based on their respective IBD sharing states. The log likelihood values are represented by the sizes of the circles, with values greater than 1 being considered reliable. C, The IBD sharing analysis plots pairs of individuals based on their shared long blocks of IBD (>12 cM). These pairings are color-coded by degrees of relatedness and represented using different shapes to distinguish interactions within and between burials, indicating extensive kinship both within individual cemeteries and across different burial sites. D, The distribution of IBD sharing among paired individuals, classified by genetic sex within cemeteries, shows no significant differences in the amount of shared IBD between male-male and female-female pairs. The number of paired individuals analyzed from each group are labelled at the top of their boxplots. Boxplots display the median (centre line), first and third quartiles (lower/upper hinges), and whiskers extending up to 1.5 × IQR from the hinges. The term “ns” indicates that the differences are not statistically significant, as determined by a two-sided t-test.