Horse males became over-represented in archaeological assemblages during the Bronze Age

Abstract

The domestication of the horse and the development of new equestrian technologies have had a far-reaching impact on human history. Disentangling the respective role that horse males and females played during this process is, however, difficult based on iconography and osteological data alone. In this study, we leveraged an extensive ancient DNA time-series to determine the molecular sex of 268 horses spread across Eurasia and charted the male:female sex ratio through the last 40,000 years. We found even sex ratios in the Upper Palaeolithic and up until~3900 years BP. However, we identified a striking over-representation of horse males in more recent osseous assemblages, which was particularly magnified in funerary contexts but also significant in non-ritual deposits. This suggests that the earliest horse herders managed males and females alike for more than one thousand years after domestication at Botai, but that the human representation and use of horses became gendered at the beginning of the Bronze Age, following the emergence of gender inequalities in human societies.

From the Eurasian Steppes to the Roman Circuses: A Review of Early Development of Horse Breeding and Management

“…Recent study showed no special preference by early horse herders for horses of a given sex until c. 3900 BP, when males began to appear much more often in osteological residues in burial sides, suggesting male-oriented preferences of Iron Age breeders [13]. Moreover, another study revealed much larger Y chromosome diversity, especially in Roman and Gallo-Roman horses [28], than in the modern population.…”

“…The first evidence of the interaction between humans and horses dates to the Lower Paleolithic period and comes from Schöningen, Germany, where numerous smashed and butchered carcasses, as well as horse bone tools, were found [12]. Initially, horses were hunted for meat and hides [13]. As an example of intensive hunting use of horses, in a small ancient hunting area in Solutré, France, the bones of between ten thousand [14] and one hundred thousand [15] horses were found.…”

An accurate assignment test for extremely low‐coverage whole‐genome sequence data

“…For instance, the genetic sex of ancient mammals can easily be assigned from sparse sequencing data due to its association with extensive genomic differentiation on a chromosomal scale. Sexing has been applied to ancient low‐coverage sequences to infer burial practices (Fages et al, 2020; Nistelberger et al, 2019), the impact of historic hunting (Barrett et al, 2020), and the behaviour of extinct species (Pečnerová et al, 2017). Aside from sex determination, other relevant biological characteristics may also be associated with large‐scale genomic differentiation.…”

Rethinking the evidence for early horse domestication at Botai

“…In contrast, demographic analysis of Botai horses by Levine 8 and a reanalysis by Olsen 22 revealed that the Botai horses are primarily breeding-age adults, split into a roughly equal balance of male and female horses. Most recently, this finding was confirmed a third time through DNA study by Fages et al 27 , who found a marked contrast between the sex ratios found in Botai and later ritual assemblages of domestic horses. Although it is possible that the inclusion of a large number of ritually-sacrificed, adult male transport horses into an otherwise predominantly female assemblage could have artificially skewed the age and sex patterns 22 , at face value, the overall mortality patterns found at Botai appear fundamentally inconsistent with pastoral management.…”