This is what distinguishes the best science from the kind of research that only confirms established ideas.

The researchers who analyzed the Mal’ta genome were prepared to find something interesting — they would not have pursued the project if they had not expected it to be informative.

But they were not prepared to find specifically this: a genetic signal in a 24,000-year-old Siberian child that connected his population to the ancestry of Native Americans through a channel that had not been clearly mapped before.

The surprise is itself scientifically significant.