Y-chromosomal evidence for a limited Greek contribution to the Pathan population of Pakistan

Abstract

Three Pakistani populations residing in northern Pakistan, the Burusho, Kalash and Pathan claim descent from Greek soldiers associated with Alexander's invasion of southwest Asia. Earlier studies have excluded a substantial Greek genetic input into these populations, but left open the question of a smaller contribution. We have now typed 90 binary polymorphisms and 16 multiallelic, short-tandem-repeat (STR) loci mapping to the male-specific portion of the human Y chromosome in 952 males, including 77 Greeks in order to re-investigate this question. In pairwise comparisons between the Greeks and the three Pakistani populations using genetic distance measures sensitive to recent events, the lowest distances were observed between the Greeks and the Pathans. Clade E3b1 lineages, which were frequent in the Greeks but not in Pakistan, were nevertheless observed in two Pathan individuals, one of whom shared a 16 Y-STR haplotype with the Greeks. The worldwide distribution of a shortened (9 Y-STR) version of this haplotype, determined from database information, was concentrated in Macedonia and Greece, suggesting an origin there. Although based on only a few unrelated descendants, this provides strong evidence for a European origin for a small proportion of the Pathan Y chromosomes.

Figure 1

A. rooted maximum-parsimony tree of Y lineages found in the Greek, Burusho, Kalash, Pathan and Pakistan. The lineages were defined by binary markers whose designations and population frequencies are given below each branch. The YCC lineage names are shown below the frequencies. Branch lengths are arbitrary.

Figure 2

Median-Joining network of clade E lineages in Pakistan (open circles) and Greece (hatched circles). Circles represent haplotypes and have an area proportional to frequency. The Pathan individuals are shown in black.

Figure 3

Contour map showing the 9 Y-STR haplotype frequency distribution in Eurasia and northern Africa. This haplotype was shared between three Greeks and a Pathan individual belonging to clade E3b1.