A groundbreaking genomic analysis of a 5,500-year-old bacterium discovered in Colombia has upended long-held assumptions about the origins of syphilis and related diseases like bejel and yaws. The study, published in Science, reveals that Treponema pallidum – the bacterium responsible for these infections – was present in the Americas millennia before European colonization, challenging theories that attribute its spread to 15th-century European outbreaks.
The Mystery of Syphilis Origins
For centuries, historians and scientists have debated where syphilis came from. One prominent theory posited that the bacterium arrived in Europe with explorers returning from the Americas after 1492. However, evidence of treponemal infections in pre-Columbian European remains complicated this narrative. It remained unclear when T. pallidum first adapted to human transmission, and whether the disease evolved before or after widespread human contact.
A 5,500-Year-Old Genome Provides Answers
Researchers stumbled upon the ancient bacterial DNA within the skeletal remains of a man from present-day Colombia. This discovery represents the oldest genetically sequenced strain of T. pallidum by over 3,000 years. Comparative genomic analysis shows this ancient strain predates all known subspecies, suggesting a much deeper evolutionary history than previously imagined.
According to co-author Nasreen Broomandkhoshbacht, the findings indicate that treponemal diseases were likely far more diverse in the past. “That opens up the question of ‘Were there an even greater diversity of the ways that this group of diseases could impact people and maybe different hosts?’” she says.
Coevolution with Humans
Geneticist Fernando González-Candelas, not involved in the study, explains that the bacterium was already well-adapted to humans by 5,500 years ago. This suggests a long period of coevolution between Treponema and humans, far earlier than suspected. The ancient strain’s presence in the Americas also challenges the notion that European colonialism was the primary driver of syphilis’s global spread.
Implications for Disease History
Mapping the evolution of ancient diseases provides insights into the lives of past communities. While the modern form of venereal syphilis evolved later, this discovery demonstrates that Treponema was already established in the Americas long before European contact. Anthropologist Elizabeth Nelson points out that “We were dealing with this way before Europeans arrived,” shifting the focus toward indigenous origins.
The study underscores that the history of treponemal diseases is more complex than previously understood, and that the bacterium’s spread and evolution were likely shaped by factors beyond colonial exchange.
This research fundamentally alters our understanding of syphilis, demonstrating that the disease has a far deeper and more nuanced history than previously believed. The ancient genome reveals a pre-Columbian presence in the Americas, forcing a reevaluation of existing theories and opening new avenues for understanding the coevolution of humans and disease.
