Alice Long holds the key to an ancient mystery at the tip of her tongue.

The 71-year-old Bar Harbor resident has always sought to learn more about her ancestors. Her grandparents emigrated from North Wales to suburban Pittsburgh in 1898. They had six daughters, a farm and a fish market. They also had some tough luck – financial struggles and, finally, a fatal run-in with the big influenza epidemic during World War I. Long’s grandmother died in the epidemic, leaving her descendants little information about family history or about her life.

“My mother never learned about Wales, anything like that,” Long said wistfully.

So when Long found out about the Genographic Project, a five-year research venture undertaken by IBM and National Geographic to trace ancient and modern migration patterns, she jumped at the chance to participate. Earlier this spring, she carefully swabbed her cheeks and sent away the extracted genetic information – and a check for $100 – in order to have her Mitochondrial DNA tested. That’s the portion of DNA that’s passed down through the mother’s mother’s mother’s mother – and so on.

Then, with bated breath, she waited weeks for the test results, knowing that they would help her understand her family tree. She didn’t foresee, however, that the tree’s roots would stretch all the way back to Africa.

“I didn’t realize they would go back 150,000 years, to Africa,” she said. “I don’t know why I didn’t realize that we would all start in the same place.”

Long laughed merrily from her desk in her Spartan genealogy room, an upstairs office furnished with a computer and maps of Wales and Mount Desert Island, in Bar Harbor.

“You have to admit, it’s pretty impressive,” she said.

A rough map of her results shows a line that begins in the highlands of East Africa with Mitochondrial Eve whom, scientists say, is the most recent common matrilineal ancestor of all humans. All people are believed to come from one small tribe of hunter-gatherers who were maybe a bit smarter, more linguistically advanced, and had better tools than their neighbors. From there, Long’s line veers north, skirting the Mediterranean and Black seas and wending through central Europe. At some point, it’s clear that some of her mother’s ancestors must have turned left and made their way to the sheep-dotted green hills of Wales.

The Genographic Project focuses on migration patterns and doesn’t give many specifics – and that’s OK with Long. Instead of neatly inscribing leaves on the family tree with names and dates, the ambitious project seeks to answer how humans came to populate the world. After 50,000 years of migration, humans had wandered onto most continents and islands on Earth and created the diverse populations found today. In the past, this puzzle could be only partially solved using ancient bones and artifacts. But scientists now have a new tool – the fact that records of prehistoric migration, through genetic mutations, lie in our genes.

“Their goal is to get aboriginal DNA, before they move or the language dies,” she said. “I think it’s a great project.”

Long’s results have been added to the vast pile of information. There is one catch, however. Because Long is female, her mitochondrial DNA tells only one piece of her story. Mitochondrial DNA is passed solely from mother to child. The Y chromosome, or male sex marker, is passed through a family’s male line and tells its own tale.

For her to learn more about her genetic past, Long had to find male relatives willing to be tested. In a far-flung family that ran towards girls, this wasn’t easy.

“I thought, how am I going to find out about my father’s line? I had to go back as far as my grandfather,” she said.

Her genealogical detective work led her back to a deceased male cousin – and his son, who lives in Slippery Rock, Pa. Long hesitated before contacting him with her unusual request.

“I paced the floor for about half an hour,” she said. “I thought, he’s going to think I’m a total idiot if I call him and tell him I want a sample of his DNA.”

He didn’t think she was an idiot. He was interested, too. Now Long has a Y chromosome to help her explain her own history – but it’s hard to stop at just one. She said that she finds the sleuthing and puzzle-solving irresistible.

“I was waking up in the night, thinking who can I get to give a DNA sample,” she said. “I’d be driving down the road. I should have had my mind on driving – and I’d think, isn’t there some way I could do my grandfather’s?”

Some of Long’s findings, through her genealogical research, have been more surprising than fiction at times. One discovery was made in a 1788 will from some of her father’s ancestors in Maryland.

“It turns out that my family in Maryland were slave owners,” she said. “That was just an absolute shock. I had just never dreamed.”

The will listed the first names of 18 enslaved people. But Long dug further, and found that in the 1790 census, they were described as “other free persons.”

As part of her genealogy work, Long seeks to educate others. She showed the 1788 will to a group of fourth-graders, to make this dark chapter of America’s past more real.

“I feel really strongly about turning people on to this. I want to get them excited about it, that’s it’s not just names and dates but what you can learn about [people], and find out what they did,” she said. “It’s been a passion my whole life.”

Abigail Curtis can be reached at 667-9395 and acurtis@bangordailynews.net.

Genealogical resources

. The Web site www.nationalgeographic.com/genographic

. The book “Seven Daughters of Eve” by Bryan Sykes, which discusses human ancestors and their genetic connection back to Africa.

. “Family Chronicle” and “Family Tree” magazines, both available at Borders and Mr. Paperback bookstores.