Lost Disease Found: Ancient Human Remains Reveal New Illness
- Scientists have reconstructed the genome of the bacterium that causes syphilis from 5,500-year-old human remains found in Colombia, pushing back the known history of this infection by over...
- The remains were excavated from a rock shelter near Bogotá.
- "Our findings show the unique potential of paleogenomics to contribute to our understanding of the evolution of species, and potential health risks for past and present communities," said...
Scientists have reconstructed the genome of the bacterium that causes syphilis from 5,500-year-old human remains found in Colombia, pushing back the known history of this infection by over 3,000 years.the discovery, published in Science, offers new insights into the evolution of treponemal diseases and their impact on human populations.
The remains were excavated from a rock shelter near Bogotá. Researchers say identifying this ancient genome expands our understanding of how long these infections have circulated in the Americas.
“Our findings show the unique potential of paleogenomics to contribute to our understanding of the evolution of species, and potential health risks for past and present communities,” said geneticist Lars Fehren-Schmitz at the University of California, Santa Cruz.
What Are Treponemal Diseases?
Treponema pallidum is a spiral-shaped bacterium responsible for several related diseases.Today,it exists in three main subspecies causing syphilis,yaws,and bejel. A fourth,pinta,is caused by either Treponema carateum or Treponema pallidum subsp.carateum. Scientists haven’t yet recovered a complete genome of the pinta pathogen, leaving its evolutionary relationships unclear.
Despite their genetic similarities, the origins of these different disease forms remain a mystery. While skeletal remains can indicate infection, genetic analysis provides a more detailed picture. theres often a disconnect between what bones reveal and what ancient DNA confirms about disease evolution.
An ancient Lineage
In this study, researchers confirmed the ancient DNA belonged to Treponema pallidum, but it differed from all known modern strains. The ancient genome represents a lineage that split off early in the bacterium’s history.
“One possibility is that we uncovered an ancient form of the pathogen that causes pinta, wich we know little about, but is known to be endemic in Central to South America and causes symptoms localized to the skin,” said Anna-Sapfo Malaspinas at the University of Lausanne and group leader at the SIB Swiss Institute of Bioinformatics. “At this time, we cannot prove this is the case, but it is indeed a lead worth investigating further.”
Genetic analysis suggests this ancient strain diverged from other T. pallidum lineages roughly 13,700 years ago. The three modern subspecies, in contrast, appear to have diverged around 6,000 years ago. These timelines support previous research and demonstrate the diversity of treponemal pathogens in the past.
Researchers acknowledge that current genomic evidence doesn’t fully resolve the debate about the origins of different disease syndromes.