Two researchers have raised questions around the role that the Botai culture of northern Kazakhstan played in the domestication of the horse.
William Taylor and Christina Barrón-Ortiz, in a paper just published in the journal Scientific Reports, questions whether horses were used by the Botai people at all for transport.
The pair, in a paper titled Rethinking the evidence for early horse domestication at Botai, noted that a scientific consensus emerged linking the Botai with the first domestication of horses, based on compelling but largely indirect archaeological evidence.
A cornerstone of the archaeological case for domestication at Botai is damage to the teeth commonly linked with the use of bridle mouthpieces, or “bit wear”.
However, recent genetic work has shown that the horse remains from Botai are not modern domestic horses but instead the Przewalski’s horse, a wild species which has never been managed or used for transport in the historic era.
This warranted a reevaluation of evidence for domestication, they said.
In their paper, Taylor and Barrón-Ortiz compared traits in horse remains hypothesized to have been caused through use in transport at Botai with wild Pleistocene equids in North America.
“Our results suggest that damage observed in Botai horse teeth is likely generated by natural disturbances in dental development and wear, rather than through contact with bridle equipment,” they wrote.
“We suggest that archaeological materials from Botai are most effectively explained through the regularized mass harvesting of wild Przewalski’s’ horses — meaning that the origins of horse domestication may lie elsewhere.”
The Botai, as horse hunters, may have represented the final chapter in a millennia-long tradition of mass harvesting of wild horses, they said.
Taylor, with the University of Colorado-Boulder Museum of Natural History, and Barrón-Ortiz, with the Royal Alberta Museum, noted how horse transport — chariots and mounted horseback riding — transformed nearly every aspect of the ancient world.
“Horse carts and riding altered the trajectories of processes such as pastoral subsistence, mobility, warfare, communication, trade, agriculture, disease and biological exchange.”
However, despite the importance of horse domestication to human history, a clear understanding of the initial domestication of Equus caballus has proven particularly elusive, with few material traces in the archaeological record with which to understand early human-horse relations.
“As a result, archaeological models for horse domestication often relied largely on indirect measures such as the frequency of Equus bones at archaeological sites, or changes in their morphological variability, to distinguish human activity.”
The discovery of “bit wear” – damage caused by a bridle mouthpiece to equine teeth — helped crystallize the emerging discipline of equine paleopathology.
“In the late 2000s, an archaeological consensus appeared to converge on sites of the Botai culture in northern Kazakhstan dating to the 4th millennium BCE, as the birthplace of horse domestication — based in no small part on the identification of apparent ‘bit wear’ on a Botai tooth,” they wrote.
However, through careful comparisons with the fossil record of Pleistocene wild horses in North America, the pair concluded that apparent instances of bit damage on Botai horses are likely generated by natural disturbances in dental development paired with natural wear.
The pair said group harvesting of horses at Botai could easily explain unresolved questions in the archaeological record, including the apparent presence of entire carcasses, the predominance of prime-aged adult animals, and the recovery of bone arrowheads in situ with deceased horse remains, as well as the utter absence of other domestic fauna at Botai.
“The relatively equal ratios of male and female animals found at Botai could imply that the site was used to harvest both bachelor bands and harem groups.
“Many of the cultural modifications found in the Botai artifact assemblage — the decoration of horse bones, the use of horse bones as tools, and even the occasional ritual inhumation of horse remains — are fully consistent with hunter-gatherer cultures in which horse hunting plays an important role.”
They said the discoveries of ritual features and artwork at Botai or Eneolithic sites from the Black Sea region, while important, fail to effectively delineate a domestication relationship from the rich hunting tradition that preceded it.
So, if the Botai did not lead the way in the use of horses for transport, who did?
“Future work will be necessary to answer this question with any confidence,” they said.
“However, we suggest that more careful attention should be paid to the domestic horses and chariots of Sintashta, and the preceding cultures of the Black Sea steppe, where horse milk proteins have recently been directly identified in human teeth dated to the 3rd millennium BCE.
“We also point to the likely significance of cultural connections between Transcaucasia and adjoining areas of the Near East, where donkeys and onagers were used for transport by the 3rd millennium BCE or before.
“In settling on a new model for horse domestication, it will be essential to revisit the findings of a rapidly changing discipline of archaeological science with fresh eyes and a willingness to reevaluate old conclusions based on new discoveries.”
Taylor and Barrón-Ortiz said the continual emergence of new lines of evidence for understanding ancient human-horse interactions necessitates a vigilant reevaluation of models for horse domestication.
Taylor, W.T.T., Barrón-Ortiz, C.I. Rethinking the evidence for early horse domestication at Botai. Sci Rep 11, 7440 (2021). https://doi.org/10.1038/s41598-021-86832-9
The study, published under a Creative Commons License, http://creativecommons.org/licenses/by/4.0/ can be read here. https://doi.org/10.1038/s41598-021-86832-9