Scientists at the University of Oklahoma hope to extract DNA from the bones, which were found earlier this year by a Delaware group dedicated to the recovery of historic aircraft.
"There's no guarantee," said Ric Gillespie, director of the International Group for Historic Aircraft Recovery in Delaware. "You only have to say you have a bone that may be human and may be linked to Earhart and people get excited. But it is true that, if they can get DNA, and if they can match it to Amelia Earhart's DNA, that's pretty good."
Lab officials said results of the tests could take week or months.
The remains turned up in May and June at what seemed to be an abandoned campsite near where native work crews found skeletal remains in 1940. The pieces appear to be from a cervical bone, a neck bone and a finger.
But Gillespie offered a word of caution: The fragments could be from a turtle. They were found near a hollowed-out turtle shell that might have been used to collect rain water, but there were no other turtle parts nearby.
"This site tells the story of how someone or some people attempted to live as castaways," Gillespie said Friday in an interview with The Associated Press. Bird and fish carcasses nearby suggested they were prepared and eaten by Westerners.
"These fish weren't eaten like Pacific Islanders" eat fish.
Gillespie, author of "Finding Amelia: The True Story of the Earhart Disappearance," has been traveling to the site since 1989. But he acknowledges there's been little progress toward solving the Earhart mystery.
"It's like science. You take the information you have and formulate a hypothesis, but 9½ times out of 10 you turn out wrong, then you go through the whole thing again - but you're closer," Gillespie said.
Millions have been spent to figure out what happened to Earhart, who was legally declared dead by a California court in early 1939. Theories have ranged from the official version - that her twin-engine Electra ran out of gas and crashed at sea - to the absurd, including abduction by aliens, or Earhart living in New Jersey under an alias.
Gillespie's book, along with "Amelia Earhart's Shoes," a 2001 book written by four other volunteers from the aircraft group, offers a reasoned thesis that Earhart and Noonan crash-landed on a flat reef near Nikumaroro Island, 1,800 miles south of Hawaii, and survived, perhaps for months, on scant food and rainwater.
The island is on the course Earhart planned to follow from Lae, New Guinea, to Howland Island, which had a landing strip and fuel. Over the last seven decades, searches of the remote atoll have produced tantalizing, if inconclusive, clues, including human bones and a sextant found just three years after Earhart vanished. The remains themselves later were lost.
Gillespie, a pilot, said she would have needed only about 700 feet of unobstructed space to land because her Lockheed Electra would have been traveling only about 55 mph at touchdown.
"It looks like she could have landed successfully on the reef surrounding the island. It's very flat and smooth," Gillespie said. "At low tide, it looks like this place is surrounded by a parking lot."
However, Gillespie said, the plane, even if it landed safely, would have been slowly dragged into the sea by the tides. Water is 1,000 to 2,000 feet deep off the reef. His group needs $3 million to $5 million for a deep-sea dive.
After the latest find, anthropologists who had previously worked with Gillespie's group suggested that he ask the University of Oklahoma's Molecular Anthropology Laboratory to try to extract DNA from the fragments for comparison to genetic material donated by an Earhart family member.
Cecil Lewis, an assistant professor of anthropology at the lab, said the university received a little more than a gram of bone fragments about two weeks ago. He preferred not to speculate about the pieces until more tests were done.
"Think how disheartened people will be if it's just a turtle bone," Lewis said.
Under the best circumstances, the analysis would take two weeks. If scientists have trouble with the sample, that time frame could stretch into months, Lewis said.
"Ancient DNA is incredibly unpredictable," he said. Gillespie said the group had tried to test possible genetic material recovered during a 2007 expedition, but a Canadian lab was unable to extract DNA from dried excrement.
Other material recovered this year also suggested the presence of Westerners at the remote island site:
- Someone carried shells ashore before cutting them open and slicing out the meat. Islanders cut the meat out at sea.
- Bottoms of bottles found nearby were melted on the bottom, suggesting they had been put into a fire, possibly to boil water. (A Coast Guard unit on the island during World War II would have had no need to boil water.)
- Bits of makeup were found at the scene. The group is checking to see which products Earhart endorsed and whether an inventory lists specific types of makeup carried on her final trip.
- A glass bottle with remnants of lanolin and oil, possibly hand lotion.
In 1940, a British overseer on the island recovered a partial human skeleton, a woman's shoe and an empty sextant box at what appeared to be a former campsite, littered with turtle, clamshell and bird remains.
Thinking of Earhart, the overseer sent the items to Fiji, where a British doctor decided they belonged to a stocky European or mixed-blood male, ruling out any Earhart connection.
The bones later vanished, but in 1998, Gillespie's group located the doctor's notes in London. Two other forensic specialists reviewed the doctor's bone measurements and agreed they were more "consistent with" a female of northern European descent, about Earhart's age and height.
On their own visits to the island, volunteers recovered an aluminum panel that could be from an Electra, another piece of a woman's shoe and a "Cat's Paw" heel dating from the 1930s; another shoe heel, possibly a man's, and an oddly cut piece of clear Plexiglas.
The sextant box might have been Noonan's. The woman's shoe and heel resemble a blucher-style oxford seen in a pre-takeoff photo of Earhart. The plastic shard is the exact thickness and curvature of an Electra's side window.
The body of evidence is intriguing, but Gillespie insists the team is "constantly agonizing over whether we are being dragged down a path that isn't right."
Associated Press Writer Kelly P. Kissel contributed to this report from Oklahoma City.