These methods are indirect and uncertain, but they can provide guidance about what ancient individuals might have looked like when the fossil record is insufficient.

The approach relies on the known relationships between specific genetic variants and specific physical traits in modern humans.

By identifying which Denisovan-specific genetic variants fall in genes known to influence physical traits, and by comparing the predicted trait values to those of Neanderthals and modern humans, researchers can make inferences about where Denisovans fell on the spectrum of ancient human morphology.

The results of such analyses suggest that the Denisovans had a distinctive combination of features: some traits similar to Neanderthals, some similar to modern humans, and some that appear to be specifically Denisovan.