In a previous experiment, I showed that Greeks can be seen as composites of two alternate sets: either a Sardinia-South Asia mix, or a North European-Near East mix. I first studied the latter, which provided a historical-period estimate for the admixture time. I now turn to the former, and use Sardinians and Brahui as parental populations. This complements previous analyses on Armenians and French using similar reference populations. Since I used the Balochi and Burusho in the two previous experiments, I decided this time to use the Brahui, which is the third population which presents a significant f3(Greek; Sardinian, Brahui) signal along the Europe-West Asia axis.
473,174 SNPs were used in total. The exponential fit can be seen below.
The jackknife estimate is 132.890 +/- 35.527 generations, or 3,850 +/- 1030 years. This spans the entirety of the Helladic period, with the mean being close to two often-cited dates for the "coming of the Greeks", corresponding to the destructions at the EHIII/MH boundary (c. 2100BC), and the spread of "Minyan ware" at c. 1900BC, although an earlier or later date is certainly possible.
(An alternative interpretation would relate the earliest Greeks to a Sardinian-like European population and the Asian component to a Luwian-like Anatolian population responsible for the well-known -nth and -ss toponyms in the Aegean.)
A signal of West Asian admixture during the Bronze is certainly consistent with my musings on the spread of metallurgy from the east during this time.