“I was pretty surprised when we didn’t find any Native American signals in our pre-contact samples,” Dr. Fehren-Schmitz said. “Honestly, at first I thought I did something wrong with the statistics. Then it was an ‘a-ha moment.’”

Scientists who were not involved in the study pointed out some of its limitations.

“This is a valuable work as it presents the first ancient whole genome data from Rapa Nui,” Víctor Moreno-Mayar, a geneticist at the Natural History Museum of Denmark, said in an email. But he cautioned that with only a handful of samples, the team did not have enough data to generalize about the genetics of the entire ancient population.

He was lead author on a paper in 2014 about the genetical testing of a sample of 27 modern Rapanui that found they inherited about 8 percent of their DNA from Native Americans. The paper also suggested that natives of South America may have come or were brought to Easter Island around 1340 A.D.

Dr. Erik Thorsby, an immunologist at the University of Oslo in Norway and his co-author, agreed.

“A few Native Americans may have reached Rapa Nui early, and their ancestral genes may be easily missed when ancient DNA from only five individuals are investigated,” he said.

Dr. Fehren-Schmitz acknowledged that the sample size was limited, but he said his investigation has shown that the history of the populations on Rapa Nui is more complicated than previously thought.