Currently, we stand alone in our existence. Yet, just hundreds of thousands of years ago, our ancestors coexisted with at least five other ancient human species, including diminutive hobbits and robust Neanderthals.

It may soon be necessary to include another name in that legacy. Recent discussions suggest that “remarkable Denisovan skulls are rewriting the narrative of human evolution,” prompting calls for the recognition of the Denisovans as a distinct species.

Since the initial Denisovan fossils were discovered 15 years ago, this isn’t a hasty conclusion. The ancient DNA retrieved from these fossils indicates they belong to humans with unique evolutionary paths. Furthermore, genetic studies suggest these ancient peoples interbred with Homo sapiens, leading many researchers to reconsider their classification as another species.

Interestingly, various species definitions permit mating as long as the involved species maintain distinct characteristics. The central issue, however, has been the unclear appearance of Denisovans. Yet, earlier this year, the discovery of ancient skulls in China—linked to Denisovan DNA—has strengthened the argument for classifying Denisovans as a distinct species based on their unique morphology.

The inclination among biologists to categorize nature into distinct species can sometimes be trivialized as mere stamp collecting. The intention is to classify life forms rather than genuinely understand them. However, in this context, the effort is meaningful. Anatomical insights from Denisovan fossils hint at a captivating possibility: these mysterious humans are closely related to our species, offering potential clarity into early behavioral advancements of Homo sapiens by juxtaposing them with Denisovans.

At a certain point, our ancestors developed new behaviors that positioned us ahead of other human races. It’s conceivable that Denisovans could shed light on how we became the last standing humans.