Table 3.
Median Errors of Geographic Localization Based on SNP Data.
| Africa | America | Asia | Europe | |
|---|---|---|---|---|
| Optimal number of PCs | 52 | 17 | 34 | 17 |
| Error (km) | 430 | 250 | 510 | 280 |
| Relative error | 0.15 | 0.10 | 0.17 | 0.24 |
| Shrinkage | 0.91 | 0.94 | 0.95 | 0.92 |
Note.—The relative errors are computed with respect to a naive localizer which assigns each individual to a population that is chosen at random among the sampled populations. The shrinkage is computed as the ratio of the mean distance between the predicted locations and the continental centroid and the mean distance between the true locations and the same centroid.