|Sex, population origin, age and average digit length as predictors of digit ratio in three large world populations.
Marina Butovskaya, Valentina Burkova, Yulia Apalkova, Daria Dronova, Victoria Rostovtseva, Dmitriy Karelin, Ruzan Mkrtchyan, Marina Negasheva & Valery Batsevich.
Recently, a number of authors have claimed that sexual dimorphism in the second-to-fourth digit ratio (2D:4D) is simply dependent on digit length and is an artifact of allometry. The goal of our study is to verify the validity of these assumptions. The study sample comprised 7,582 individuals (3,802 men and 3,780 women) from three large world populations: Europeans (n = 3043), East Africans (n = 2844), and Central Asians (n = 1695). The lengths of the second and fourth digits on both hands were measured. Digit ratios were computed according to standard procedures. Analyses were conducted separately for each hand for the whole sample and in succession for the three large populations. Additionally, we separately tested four age cohorts (≤ 13, 14–18, 19–30, and 31 ≥ years) to test the effect of developmental allometry. The second and fourth digits showed strong positive linear relationships on both hands, and demonstrated an increase with age; digit length in women from the youngest age cohort was longer or equal to that of men, and shorter than men in older age cohorts. However, the 2D:4D magnitude and its sexual dimorphism remained stable throughout the ontogeny. To test for an allometric effect on 2D:4D, the average digit lengths were calculated. Both sex and population origin were permanent reliable predictors of 2D:4D, whereas average digit length was not. Height was applied as another measure of allometric effect on the limited sample (≤ 30 years) from the European population, along with sex and age. No allometric effect was observed in this case. We conclude that sex differences in 2D:4D are not an artifact of allometry. Перейти к статье
Ancient genomic time transect from the Central Asian Steppe unravels the history of the Scythians.
Guido Alberto Gnecchi-Ruscone, Elmira Khussainova, Nurzhibek Kahbatkyzy, Lyazzat Musralina, Maria A. Spyrou, Raffaela A. Bianco, Rita Radzeviciute, Nuno Filipe Gomes Martins, Caecilia Freund, Olzhas Iksan, Alexander Garshin, Zhassulan Zhaniyazov, Bakhytzhan Bekmanov, Egor Kitov, Zainolla Samashev, Arman Beisenov, Natalia Berezina, Yakov Berezin, András Zsolt Bíró, Sándor Évinger,Arman Bissembaev, Gaziz Akhatov, Aslan Mamedov, Akhan Onggaruly, Dmitriy Voyakin, Aidos Chotbayev, Yeldos Kariyev, Alexandra Buzhilova, Leyla Djansugurova, Choongwon Jeong, Johannes Krause. Abstract:
The Scythians were a multitude of horse-warrior nomad cultures dwelling in the Eurasian steppe during the first millennium BCE. Because of the lack of first-hand written records, little is known about the origins and relations among the different cultures. To address these questions, we produced genome-wide data for 111 ancient individuals retrieved from 39 archaeological sites from the first millennia BCE and CE across the Central Asian Steppe. We uncovered major admixture events in the Late Bronze Age forming the genetic substratum for two main Iron Age gene-pools emerging around the Altai and the Urals respectively. Their demise was mirrored by new genetic turnovers, linked to the spread of the eastern nomad empires in the first centuries CE. Compared to the high genetic heterogeneity of the past, the homogenization of the present-day Kazakhs gene pool is notable, likely a result of 400 years of strict exogamous social rules. Перейти к статье