Researchers have reported that analysis of a bone fragment that could conceivably be from missing pilot Amelia Earhart’s finger are, to date, inconclusive.

The bone fragment was found on Nikumaroro, known at the time of Earhart’s 1937 disappearance as Gardner Island, where circumstantial evidence suggests the missing flyer and her navigator, Fred Noonan, landed and lived for a time as castaways only to eventually perish on the uninhabited, waterless atoll.

A non-profit group - The International Group for Historic Aircraft Recovery (TIGHAR) - is testing the hypothesis that Earhart died as a castaway on the uninhabited Pacific atoll. The bone fragment’s structure and the context in which it was found have led TIGHAR to wonder if it might be part of a human finger.

TIGHAR also asked University of Oklahoma researchers to evaluate small clumps of material recovered from an archaeological site on Nikumaroro to determine whether they might be human fecal matter.

Cecil Lewis Jr. of the University of Oklahoma's Molecular Anthropology Laboratories said the question of whether the bone is human must remain unanswered. We were not able to retrieve sufficient DNA from the bone sample to be able to provide any definitive statements on the bone’s origin.

Researchers said initial tests to detect possible human mitochondrial DNA in the bone fragment were positive, but they were unable to repeat the result.

Nevertheless, there is reason for optimism that some day in the near future, less destructive, and more sensitive genomic methods will be able to resolve the bone’s origin, Lewis said.

TIGHAR said it agreed with Lewis’ recommendation that further testing on any of the bone fragments should await the development of new technologies and techniques in the rapidly advancing field of DNA research.