Ancient Ecuadorian Genomes

Ancient genomes from coastal Ecuador reveal 1,500 years of genetic continuity in an understudied part of the ancient world. John Lindo and colleagues sequenced four genomes from individuals excavated at Salango on Ecuador's central coast, from around 2,300 years ago, 1,900 years ago, and 740 years ago. The four genomes cluster with ancient and present-day populations from Ecuador, Colombia, and Peru, consistent with shared ancestry within a northwestern South American genetic continuum. The Salango population likely diverged from other Southern Native Americans around 9,800 years ago. All four individuals showed genetic similarities, suggesting population continuity at Salango despite major cultural and environmental changes, including the aftermath of the Pululahua volcanic eruption around 2,360 years ago, the rise of chiefdoms, and the development of maritime and overland trade. In addition, one individual, an infant, exhibited skeletal lesions consistent with tuberculosis. The researchers recovered DNA from the Mycobacterium tuberculosis complex and reconstructed a pathogen genome, providing rare genetic evidence of tuberculosis in the pre-contact Americas. According to the authors, the study opens new opportunities to trace both population history and infectious disease along South America's Pacific coast.