International Team Examines History of North American Horses

Combining genomic, isotopic, radiocarbon, and paleopathological data, an international team that included scientists from the University of Colorado, Boulder and the French National Centre for Scientific Research has conducted an extensive analyses of North American horses. As reported in Science this week, the group shows that most of these animals descended from Spanish horses, with later genetic influx from British horses. They also determined that horses rapidly spread from the south into the northern Rockies and Great Plains by the first half of the 17th century, likely through the exchange networks of Indigenous people. Analyses of herd management, ceremonial practices, and culture, meantime, reveal that horses were already deeply integrated into these societies by the time Europeans arrived in the region in the 18th century. "This study demonstrates that colonization did not just drastically affect Indigenous peoples but also their horses, whose genetics captures an ancestry shift from Spanish to British bloodlines," the study's authors write.