High Y‐chromosomal Differentiation Among Ethnic Groups of Dir and Swat Districts, Pakistan

Abstract

The ethnic groups that inhabit the mountainous Dir and Swat districts of northern Pakistan are marked by high levels of cultural and phenotypic diversity. To obtain knowledge of the extent of genetic diversity in this region, we investigated Y-chromosomal diversity in five population samples representing the three main ethnic groups residing within these districts, including Gujars, Pashtuns and Kohistanis. A total of 27 Y-chromosomal short tandem repeats (Y-STRs) and 331 Y-chromosomal single nucleotide polymorphisms (Y-SNPs) were investigated. In the Y-STRs, we observed very high and significant levels of genetic differentiation in nine of the 10 pairwise between-group comparisons (R 0.179-0.746), and the differences were mirrored in the Y-SNP haplogroup frequency distribution. No genetic differences were found between the two Pashtun subethnic groups Tarklanis and Yusafzais (R = 0.000). Utmankhels, also considered Pashtuns culturally, were not closely related to any of the other population samples (R 0.451-0.746). Thus, our findings provide examples of both associations and dissociations between cultural and genetic legacies. When analyzed within a larger continental-scale context, these five ethnic groups fall mostly outside the previously characterized Y-chromosomal gene pools of the Indo-Pakistani subcontinent. Male founder effects, coupled with culturally and topographically based constraints upon marriage and movement, are likely responsible for the high degree of genetic structure in this region.

Contrasting maternal and paternal genetic histories among five ethnic groups from Khyber Pakhtunkhwa, Pakistan

“…In neighboring Afghanistan, R1a1a-M17 is frequent among Pashtuns (51.02%) and Tajiks (30.36%) but less so in Uzbeks (17.65%) and Hazaras (6.7%) 95 . In addition, it has been observed at high frequency (~ 80%) among Yousafzais of Swat Pakistan 82 , a finding consistent with our data.…”

“…The MJ networks of the major common NRY haplogroups show that flow of paternal lineages among the five ethnic groups is quite limited and consistent with high levels of male endogamy practiced by them. Similar Y-chromosome results have been previously reported for Central Asian and South Asian ethnic groups 44 , 82 , 91 , 100 , 135 , 136 , but with less pronounced genetic differentiation in maternal lineages 135 – 138 .…”

“…The NJ tree revealed different genetic affinities of the KPP populations. Gujars from our study clustered tightly with a Gujars population from Punjab 123 , Yousafzais from this study clustered closely with populations from South Afghanistan 104 and other Yousafzai groups 82 , 83 . In addition, the Syeds from our study were positioned close to a Tarklanis population from the Dir District of Pakistan 82 .…”

“…Gujars from our study clustered tightly with a Gujars population from Punjab 123 , Yousafzais from this study clustered closely with populations from South Afghanistan 104 and other Yousafzai groups 82 , 83 . In addition, the Syeds from our study were positioned close to a Tarklanis population from the Dir District of Pakistan 82 . By contrast, Jadoons and Tanolis generally clustered somewhat near each other and with Turkmen population from Central Asia and ethnic groups from northeast India.…”

“…Four of these haplogroups (G2a, R1a, J2a1b, I2a) are likely associated with male-mediated migrations related to Neolithic farming 45 , 98 , 101 , 170 , 171 . They also exhibit genetic affinities with other Yousafzais populations 82 , 83 . The Yousafzais also exhibit considerable mtDNA diversity.…”