Extended Data Figure 3. Using allelic mismatch rates patterns along the chromosomes to differentiate types of relationships for individuals sharing the same amount of DNA.

a, Differentiating between parent-offspring and sibling relationships. Allelic mismatch rate values across sliding windows of 20 Mb, moving by 1 Mb each step. As an example, we show values at chromosome 17 and include for reference a comparison between two unrelated Neolithic individuals from Britain (in brown), and a comparison between one individual and himself (in purple) to show how mismatch rates behave when two chromosomes are shared. The mismatch rate pattern for SP1m-SC1f is compatible with one chromosome shared along the entire chromosome 14 (in fact, along all autosomal chromosomes (Supplementary Table 6)), indicating a parent-offspring relationship. In contrast, the NC7f-SP3m comparison shows regions on chromosome 17 where no chromosome is shared (~65–70 Mb), other regions where two chromosomes are shared (~0–25 Mb) and other regions where one chromosome is shared (~25–60 Mb), compatible with a sibling relationship. b, Comparing DNA sharing patterns between SC9f and her paternal grandparents. We show mismatch rate values at chromosome 2 and include for reference a parent-offspring comparison (SE1m-SP2m; in blue) to show how mismatch rates behave when one chromosome is shared. Two recombination events (one at ~145 Mb and other at ~220 Mb) in SC9f’s father’s gamete result in SC9f’s sharing one chromosome with SC3m from the start of the chromosome to ~145 Mb, one chromosome with SC4f from 145 to 220 Mb and one chromosome with SC3m from 220 Mb to the end of the chromosome. This pattern of sharing one chromosome with either SC3m or SC4f at every location of the genome is characteristic of comparisons between a grandchild and his/her two grandparents and is also observed in the other autosomal chromosomes.