But the discovery it reports is one of the most extraordinary in the history of paleoanthropology.

The gap between the language in which it is described and the magnitude of what it means is worth reflecting on.

For two centuries, paleoanthropologists have been trying to understand the relationship between ancient human species — how they related to each other biologically, whether they could interbreed, whether the categories we use to describe them (Neanderthal, Denisovan, modern human) reflect real biological divisions or are human-imposed labels on a continuum of variation.

Denny answers one part of that question with finality: yes, at least some of these groups could interbreed and produce viable offspring.