What evidence identifies Denisovans as a distinct human lineage?

The identification of Denisovans as a distinct human lineage is primarily supported by genetic evidence and, to a lesser extent, fossil remains.12

Genetic Evidence

The most definitive proof of their distinct status comes from the sequencing of their genome. In 2010, researchers sequenced the mitochondrial DNA (mtDNA) from a finger bone found in Denisova Cave. The results showed nearly twice as many differences from modern human mtDNA as those found in Neanderthal mtDNA, indicating that the Denisovan lineage diverged from a common ancestor long before the split between Neanderthals and modern humans. Subsequent analysis of their nuclear genome confirmed that they were genetically distinct from both Neanderthals and Homo sapiens.21

Fossil Evidence

Physical remains, including finger bones, molars, and partial mandibles, provide supporting evidence. Specifically, teeth excavated from Denisova Cave exhibited structural features not found in either Neanderthals or modern humans, further distinguishing the group as a unique hominin population.12