New admix technique: phased haplotypes + virtual genomes

[warwick]

http://www.plosgenetics.org/article/info%3Adoi%2F10.1371%2Fjournal.pgen.1002410

Someone posted this at 23andme, and it is interesting:

Excerpt:
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We next used SABER+ to estimate recombination breakpoints between ancestral chromosomes and thus locus-specific ancestral origin— Indigenous American, European, or African—in individuals from the MEX1 and MEX2 cohorts....we constructed virtual genomes by retaining haplotype segments from a single continental-ancestral population, while masking (i.e. setting to missing) segments from all other ancestral populations; for example, MEX1AMR and MEX1EUR denote the sets of Indigenous American and European haplotype segments from the Mexico City individuals, respectively...We first computed the theoretical number of ancestry blocks for individuals according to their ancestral proportions, and carried out that computation assuming a series of different admixing times (5–25 generations, dotted lines in Figure 2D)....We then superimposed the observed number of ancestry blocks in each MEX1 individual onto the theoretical curves; these results suggest an admixing time of 10–15 generations ago (Figure 2D). The admixing time of the European component appears slightly longer than that for the Indigenous American component (15 generations vs. 12);