They compared the specific genetic variants to the known Neanderthal and Denisovan genomes that the laboratory had previously characterized.

They verified the authenticity of the ancient DNA through damage pattern analysis.

And the result held.

The data was real.

The 50-50 split was real.

The chromosome-level pattern was real.

Denisova 11 was, definitively and without any ambiguity, the first-generation offspring of a Neanderthal mother and a Denisovan father.

The recognition of this fact — the moment when the verification was complete enough that the team could be confident of what they had found — must have been something like what scientists describe when major discoveries happen: a period of escalating confidence that gives way to a kind of quiet awe, followed by the realization of the implications, followed by the need to tell people.