She is the proof that the neat categorical distinctions we use to describe ancient humans — Neanderthal, Denisovan, modern human — describe real but not absolute differences.

The boundaries were permeable.

The categories were real but not rigid.

And the children of those permeable boundaries — Denny and others like her who were never found — were part of the ancient world in ways that left traces in us.

The Modern Inheritance

The genetic legacy of the Neanderthal and Denisovan lineages in modern human populations is not merely a historical curiosity.

The specific DNA sequences that ancient humans contributed to modern humans have, in many cases, identifiable functional effects — effects that are still playing out in the bodies of modern people today.