Horses revolutionized human history by increasing mobility, but the timeline between their domestication and widespread integration as a form of transportation remains debated.
Genetic evidence suggests that modern domestic horses emerged around 3000 BC in the steppes of western Eurasia, including an area inhabited by nomadic peoples known as the Yamnaya.
According to some accounts, the Yamnaya people migrated to Europe on horseback.
The earlier appearance of a different lineage of domesticated horses (probably used for milk) in association with the Botai culture of Central Asia (context: c. 3500 BC) also adds confusion.
To explore the possible timing of domestication, Dr. Ludovic Orlando of the Toulouse Centre for Anthropology and Genomics, Dr. Pablo Librado of the Barcelona Institute of Evolutionary Biology and their colleagues analysed the genomes of 475 ancient horses and 77 modern horses.
“I started working with horses about 10 years ago, and at the time there were only a few ancient genomes,” Dr. Librado said.
“With this new study, we now have hundreds of specimens. The increased resolution over Central Europe, the Carpathians and the Transylvanian Basin was particularly important, as this region was at the heart of the ongoing debate about a large-scale horse-driven migration out of the steppes around 5,000 years ago, or maybe even earlier.”
The researchers found that around 2200 BC there was a clear change in horse breeding practices (including the introduction of inbreeding), which resulted in the replacement of almost all horse bloodlines with modern livestock bloodlines.
This expansion was preceded by a domestication bottleneck (starting around 2,700 BC) that shortened generation times (related to the age at which horses breed) and made it easier to breed new domestic horses.
Previous studies have suggested that the Yamnaya migration occurred between 3,300 and 2,600 BCE.
The timing suggested by this study is therefore inconsistent with the hypothesis that the Yamnaya-related steppe peoples were accompanied by large herds of modern domesticated horses.
The authors also found evidence of domestication of the Botai horse, including shortened generation times, which means that horse domestication may have occurred in some areas before 2700 BC, but did not lead to widespread migration of horses.
“One question I've long wondered about is the scale of production: how was it possible to suddenly keep such large numbers of horses from a relatively small livestock area to meet growing global demand by the turn of the second millennium BC?” Dr Orlando said.
“Now we have the answer: breeders have controlled the reproduction of the animals so well that the time interval between two generations has been almost halved.”
“Simply put, they were able to speed up the breeding process and essentially double their production rate.”
“Our methodology for measuring temporal changes in generation time has great potential,” Dr. Librado explained.
“This adds a new method to the archaeozoological toolkit for monitoring the development of managed breeding in a range of livestock species beyond horses.”
“But it could also help shed light on generation intervals in our hunter-gatherer ancestors and how these intervals evolved alongside changing lifestyles and significant climatic changes.”
“Our evidence supports two stages of domestication of the horse,” Dr Orlando said.
“The first attempts, which occurred around 5,500 years ago, were aimed at addressing the decline of horse populations and providing food for people living on the steppes of Central Asia.”
“The domestic horse as we know it emerged from a second period of domestication about 4,200 years ago.”
“This allowed high-speed travel for the first time and truly changed human history.”
of study Published in this week's journal Nature.
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P. Librado otherHorse travel became widespread in Eurasia around 2200 BC. NaturePublished online June 6, 2024; doi: 10.1038/s41586-024-07597-5
Source: www.sci.news
