The object was small, dry, and dark.

It had survived in the sediment of an Oregon cave for thousands of years, long enough to become mineralized into a compact mass that archaeologists call a coprolite — ancient preserved feces.

It did not look like evidence of anything extraordinary.

It looked like something that should be ignored.

Scientists did not ignore it.

When researchers extracted material from coprolites found in Paisley 5 Mile Point Caves in south-central Oregon and ran it through ancient DNA analysis, they found human mitochondrial DNA.

Specifically, they found genetic sequences belonging to Native American founding haplogroups — the maternal lineage markers that trace a continuous thread from the first people who entered the Americas to Indigenous communities living today.

The coprolites were directly radiocarbon dated.

When those dates were calibrated to calendar years, the oldest specimens fell in a range that researchers have characterized as approximately 14,200 to 14,300 years ago.

That placed them before Clovis.

The Clovis culture — defined by its distinctive fluted stone points, found at sites across North America — had been understood for decades as the earliest clearly documented human presence on the continent.

Its archaeological horizon sat at roughly 13,000 to 14,000 calibrated years before present.

The Paisley coprolites appeared to predate that by a meaningful margin.

A discovery that should have closed an argument instead opened a fight.

Within a year of the original publication in Science in 2008, published scientific criticisms appeared in the same journal.

Was the mitochondrial DNA actually inside the coprolites when they were deposited — or had it migrated downward through the sediment from later layers?

Could a non-human coprolite, lying in sediment where humans had also been present, absorb environmental human DNA?

Were the cave’s stratigraphic layers genuinely undisturbed, or had mixing occurred?