But Dr. Mahli decided to join the team when Dr. Willerslev began meeting with local tribes. “My mind changed when I realized Eske was engaging with these communities,” he said.

“He has been great through all of this,” Jackie M. Cook, the repatriation specialist for the Confederated Tribes of the Colville Reservation, said of Dr. Willerslev.

The Kennewick Man genome, like the Anzick child’s, revealed an ancient continuity between living Native Americans and the earliest people in the New World. After Dr. Willerslev and his colleagues published their results last year, John Novembre of the University of Chicago confirmed them at the request of the Army Corps of Engineers.

Dr. Willerslev has mixed feelings about the consequences of his research on Kennewick Man.

“I’m a scientist, and it means I regret that important material is getting reburied,” he said. “But when you find that these remains are genetically Native Americans, it’s not our call anymore.”

Since the Kennewick Man project, Dr. Willerslev has hosted visits from a number of Native American tribes to his laboratory in Copenhagen. His guests have helped him see how differently he, as a European, treats history than they do.

Dr. Willerslev once proudly showed off a collection of ancient Danish skulls to Native American visitors, only to find them upset by the sight.

“‘How can you treat your ancestors like that, so disrespectfully?” he recalls them asking.

In December, Dr. Willerslev hosted Dr. Doyle along with Ben Cloud and Frank Caplett, also members of the Crow Nation. Dr. Willerslev took them around the lab and proposed research he hoped the tribe would consider.