Единственная работа по хотонам, которую я нашёл: https://web.archive.org/web/20071008104359/http://www.imbice.org.ar/es/lab_06_b/06.pdf
The Khoton population is one of the smallest groups, residing only in northwestern Mongolia. This population is considered to be a small group of Turkish origin that migrated into Mongolia in the seventeenth century (Nyambuu, 1992). We analyzed 16 binary and 17 STR markers to study the paternal genetic variation of these four ethnic groups. The results were then compared with those analyzed for five East Asian populations (Manchu, Northern Han, Korean Chinese, Korean, and Japanese). The present study revealed that the major Mongolian ethnic groups have a relatively close genetic affinity to the northern part of East Asia. However, our study also revealed that the Khoton population has a closer relationship to Central Asia than to the other Mongolians, implying that the genetic link between Mongolia and Central Asia is not negligible...
Haplogroup R1a1 was observed at the highest frequency in the Khoton population (83%) and at low frequencies in the Khalkh, Uriankhai, and Zakhchin populations (4 to 13%). This haplogroup was not observed in any East Asian populations. This haplogroup has been shown to be generally frequent in Central Asian populations (Karafet et al., 2001; Zerjal et al., 2002). Thus, the frequency distribution patterns of Y-SNP haplogroups in the Khoton population were similar to those of Central Asian populations rather than those of the other Mongolian populations
The frequency distributions of the binary haplogroups showed that the Khoton population had a higher frequency of haplogroup R1a1 than did any other population. According to previous studies, this haplogroup shows a high frequency in Central Asia and a relatively low frequency in the Caucasus, the Middle East, and East Asia (Semino et al., 2000; Karafet et al., 2001). Zerjal et al. (2002) speculated that this haplogroup came from the expansion of early nomadic groups in Central Asia. In addition, the MJ network in the Khoton population showed a unique topology that would represent a recent bottleneck. These results suggest that the Khoton population has a history that differs from that of the other Mongolian populations. Notably, previous anthropological studies have suggested that the Khoton population was most closely related to the Kirghiz, Kazakh, and Uzbek populations of Central Asia, which are in turn typical representatives of the Southern Siberian populations (Batsuuri, 1977). Historical studies have suggested that the Khoton population originated from a small number of individuals of Turkish origin who recently migrated into the present territory of Mongolia (Nyambuu, 1992).
Исследовали ли хотонов где-то ещё? Крайне интересно, что у них за субклады R1a? Судя по графику выше, не так уж всё и однородно, как сказано в самой работе, т.к. явно есть несколько веток. И для выборки в 30 человек это очень даже хорошее разнообразие. Интересно и R1a у других народов Монголии (захчин, халха, урянхай).