By the time he approached the Fallon Paiute-Shoshone Tribe about the Spirit Cave Man, Willerslev had already conducted ancient DNA analyses on some of the most important ancient human remains in the world.

He had sequenced the genome of a 4,000-year-old Greenlandic Inuit man — one of the first complete ancient human genomes ever analyzed.

He had worked on Pleistocene-era remains from various parts of the world.

He understood, from experience, both what ancient DNA could reveal and what it could not.

He also understood the ethical dimensions of working with Indigenous communities on the remains of their ancestors.

His record in this regard was mixed by his own acknowledgment — in earlier work on Arctic peoples, his team had faced criticism about the adequacy of community consultation.