Table 1 Summary of GLOBETROTTER’s inference of the date of admixture and composition of admixing sources for each of four geographic regions of Denmark
Admixture event 1Admixture event 2
RegionBest fitting type of admixtureGoodness of fit (R2)Years before present (95% CI)YearMinor componentMajor componentRatioMinor componentMajor componentRatio
Zealand (N = 36)1 date multiway0.208943 (579, 1488)1052BRISWE0.47:0.53GERPOL0.47:0.53
S. Jutland (N = 37)1 date multiway0.136756 (232, 1548)1239FRAPOL0.21:0.79GERPOL0.43:0.57
C. Jutland (N = 89)1 date multiway0.354611 (418, 823)1384BRIPOL0.31:0.69POLGER0.45:0.55
N. Jutland (N = 48)1 date multiway0.239434 (118, 741)1561BRIPOL0.33:0.67GERPOL0.42:0.58
  • Type of admixture was chosen among three alternatives: (i) one date, (ii) one date multiway, and (ii) two or more dates. Multiway admixture involves two admixture events. If a source population appears in both admixture events 1 and 2, then the interpretation is “three-way admixture” (for more details see Busby et al. 2015). R2: goodness of fit for a single date of admixture, taking the maximum value across all inferred coancestry curves (R2 ≥ 0.2 corresponds to good fit). GLOBETROTTER returns date estimates in generations. We multiplied these estimates by 30 years/generation. We retrieved historical dates by subtracting year estimates from 1995 (the median year of birth for our high school students). CI: confidence interval.