Ancient poop dating back about 14,000 years found in an Oregon cave is of human origins, Gizmodo reports. It adds that an initial genetic analysis suggested the coprolites were from people, a finding now bolstered by lipid biomarker analysis.
According to Gizmodo, archaeologists collected dozens of coprolite samples from the cave, including ones that date to before the emergence of the Clovis culture about 11,500 years ago. The Clovis people were once thought to have been the first inhabitants of North America, a theory Gizmodo notes is in doubt. While a mitochondrial DNA analysis suggested the feces harbored human mtDNA, the results were questioned because dog genetic material was also present, suggesting possible contamination, it notes
Researchers from the US and UK have now instead analyzed lipid biomarkers within three fecal samples. As they write in Scientific Reports, they confirmed the three of the six pre-Clovis samples previously suspected to be of human origin by mtDNA analysis were indeed human based on their sterol and bile content.
"We still have a lot to learn about when the first people arrived in the Americas, where they came from, and what routes they took to get here," co-author John Blong from Newcastle University tells Gizmodo. "Our study adds to growing evidence that people were in the Americas more than 14,000 years ago, prior to the widespread Clovis culture."