New archaeological research is reshaping the story of how the first people spread across the Americas. A study in Science Advances suggests that early populations may have moved south by following large Ice Age herbivores such as mammoths, gomphotheres, and giant ground sloths.
Researchers led by Ben Potter of the University of Alaska Fairbanks and James Chatters of McMaster University analyzed animal remains and tools from 50 sites across Alaska, North America, and South America. Their comparison included Eastern Beringians, Clovis groups, and Fishtail Projectile Point traditions.
The team found that megaherbivores -- plant-eaters weighing more than 1,000 kilograms -- accounted for most of the edible biomass in these regions. In their model, these animals made up about 83% to 88% of available food resources. Mammoths were especially important in Beringia and North America, while giant ground sloths and gomphotheres played a larger role farther south.
The study argues that this hunting strategy may have helped small mobile groups adapt quickly to new environments. Large prey were widespread and familiar, which could have made long-distance expansion more efficient than relying on local plants or small game.
Still, a second paper in the Journal of Archaeological Science: Reports adds caution. Metin Eren of Kent State University and colleagues reviewed 15 North American sites with Clovis points and proboscidean remains, but say the evidence does not always prove a direct kill. In some cases, the bones and tools could also fit scavenging behavior.
That debate highlights a classic archaeological challenge: different actions can leave similar traces. Even so, both studies point to the same broad picture -- early Americans were highly adaptable, technologically skilled, and deeply connected to the rhythms of Ice Age landscapes. This research may help future archaeology refine how human mobility and survival shaped the peopling of the Americas.