Researchers examining ancient DNA have narrowed down the timeline of early human migration into North America — shedding light on a question that's puzzled scientists for decades.The study, published online ahead of its appearance in the December 2026 issue of the journal Current Opinion in Genetics & Development, looked at previously published genetic and archaeological evidence to better understand when humans first arrived in the Americas.Genetic evidence most strongly supports humans reaching the Americas between 14,000 and 20,000 years ago, the study suggests — with an arrival before 15,000 years ago considered likely.CAVE DISCOVERY PUSHES BACK EVIDENCE OF HUMAN ANCESTORS USING FIRE TO 1.79M YEARS AGOPreviously, scientists thought the first humans arrived in North America roughly 13,500 years ago, a theory known as "Clovis First."Later archaeological discoveries have challenged that timeline, suggesting humans may have reached North America thousands of years earlier.Researchers examining ancient DNA have narrowed the timeline of early human migration into North America — offering fresh insight into a decades-old scientific mystery.(Museum of London/Heritage Images/Getty Images)The researchers, led by Bethany Potter and Savannah Hay of the University of Kansas, reviewed existing ancient DNA and archaeological evidence, including 23,000-year-old human footprints found at White Sands National Park in New Mexico.The footprints suggest humans may have inhabited North America earlier than the timeline supported by currently available genetic evidence.DNA FROM THOMAS JEFFERSON'S HAIR DELIVERS COMPELLING NEW EVIDENCE IN CENTURIES-OLD PATERNITY MYSTERYSuch early populations could have belonged to genetic lineages that have not yet been sampled or that left no surviving descendants, the researchers said. By comparing previously published genetic data from ancient human remains in Asia and the Americas, researchers examined shared ancestry to trace how early ...