Our shared ancestry: Chemistry professor offers tips for tracing your genetic family
"Genealogy is the fastest growing and second most popular hobby in the United States," says Rob Flanagan Stieglitz, 67, a retired chemistry professor.
With the advancement in DNA testing, amateur genealogists have a new, powerful tool, he says.
Stieglitz recently taught a Park Rapids community education class to share advice and resources gleaned from his scientific background and 20 years of family history research.
"With multiple sources of historical records available on the internet, it now makes it possible to work on your research from the comfort of your home," Stieglitz said.
Social media, like Facebook, make it easy to reach out to newly discovered relatives worldwide.
"One of the things I like about it is I've contacted family in Germany and Ireland that I'd never, ever imagined were there, for one thing, but to be able to connect with them so easily and converse with them so easily in real time, it's unbelievable. It's fun."
Our collective past
An insatiable curiosity about human genetics triggered Stieglitz's eventual interest in his own ancestry.
He joined a joint scientific study by Harvard graduate Spencer Wells, a geneticist, and the National Geographic Society. It was a real-time study that encouraged public participation.
"He and his colleagues realized that, in DNA, you can trace the footsteps of mankind. It's become an archaeological tool, much better than artifacts," Stieglitz said.
Since its launch in 2005, National Geographic's Genographic Project has used advanced DNA analysis and worked with indigenous communities to help answer fundamental questions about where humans originated and how we came to populate the Earth.
There were, at one time, 17 distinct human species. Through the Genographic Project, Stieglitz discovered he has both Denisovan and Neanderthal DNA — two species now extinct — because his long-ago ancestors migrated from Asia to Europe.
Three types of DNA may used in genealogical testing: autosomal, Y-chromosome and mitochondrial.
Understanding the science of DNA begins at the cellular level.
DNA is contained in both the nucleus and mitochondria of a human cell. Nuclear or "autosomal" DNA has 22 pairs of chromosomes. Scientists have numbered these chromosomes by size, from 1 (the largest) to 22 (the smallest).
"The chromosome is just a package that protects the DNA itself. The DNA is just a long, molecular compound protected by a protein cover," Stieglitz said. "A chromosome is considered a pair. The reason it's a pair: One side is what you got from your mother, the other side is what you got from your father."
When sperm fertilizes an egg, it takes its 23 single chromosomes and they combine with the egg's to make 23 pairs.
The 23rd chromosome pair determines a person's gender. Males have an X and Y chromosome pair; females have two Xs.
Companies like FamilyTreeDNA, AncestryDNA and 23andMe analyze your autosomal DNA, Stieglitz explained, but it can confirm relationships going back only seven generations.
This is because the average amount of autosomal DNA shared with a relative decreases with each successive generation — like a 23-card deck that gets reshuffled each time someone is born.
Y-DNA, on the other hand, is passed down only from a father to all his male descendents. Using this DNA, a direct male line can be accurately traced back 338,000 years.
"If I went back and found a Stieglitz that died in 1300, his Y-DNA would be identical to mine," he explains.
The same is true of mitochondrial DNA.
Mitochondria are within every human cell, but are not part of the nucleus. Considered the power generators of the cell, mitochondria have their own circular piece of DNA.
"Mitochondrial DNA is very, very unique," said Stieglitz, adding it has nothing to do with mixture of a father's and mother's genes inside the cell's nucleus.
Mitchondrial DNA is passed only by the mother to all of her biological descendants. Using this DNA, a direct female line can be precisely traced back 200,000 years.
Scientists hypothesize that millions of years ago mitochondria were small, single-celled organisms engulfed by larger organisms, he noted.
The Genographic Project "found people living in Africa that basically have a Y-DNA and mitochondrial DNA that we all contain. Everyone has the basic blueprint, but there are 'markers' or mutations. Those changes in DNA — eye color, skin color, hair color, size — become changes in appearance," said Stieglitz.
"When you send your DNA in, they will take a look at all your markers. Basically, they can backtrack from how your ancestors moved out of Africa," he continued. "It's that mistake that takes place in the DNA structure that they use then to determine connections with people or a group of people or places in time in the world."
A personal quest
In 1997, Stieglitz's mom was diagnosed with cancer.
"My objective was to find where her family came from in Ireland. Well, I didn't realize that was such a big chore," he said. "It was so challenging, but I found it before she died."
A family tree provided by his maternal grandmother in the 1970s proved to be wrong. All she knew was two misleading family stories.
By delving into birth records, marriage certificates, death certificates, newspaper articles, obituaries and the like, Stieglitz determined his Irish ancestors immigrated to New York City during Ireland's Potato Famine between 1851 and 1867. They lived in poverty in what became known as "Hell's Kitchen."
His paternal grandparents were born in Germany. Stieglitz can trace these ancestors to a castle in Germany in 1500. "We didn't own the castle. We were the gardeners," he said.
He hit a "brick wall" while tracing his maternal Irish family.
"Paper trails end. It's an exhaustive search."
When the family historian can no longer find viable documents, DNA becomes another tool.
Genealogical DNA tests can cost anywhere from $56 when on sale to $186.
"The DNA test is not to tell you your ethnicity, which they advertise because they think it's a good marketing tool," Stieglitz warns. "We're doing it to connect with people, to find out who has matching DNA," along with coinciding family records.
For example, Stieglitz's DNA results claimed he was British and Danish.
"Someone would get that information and say I'm British and Danish and I always thought I was German and Irish," he said.
Placing a geographic location or ethnicity on DNA becomes tricky because a country's borders change.
The Stieglitzs came from north Germany, which for 750 years was part of Denmark.
"That means my genetic pool, even though my family spoke German and was Germanic in people, our genetic pool is a mixture of people that lived in this area. They were Danish Vikings and a mixture of Anglo-Saxons," he explains.
It's the same with his Irish background.
When the glaciers receded 10,000 years ago, Ireland was repopulated by the Celts (who invaded in 500 BC), the Vikings (800 AD) and the Normans (1100 AD).
"So you really have to talk about groups of people and periods of time and not geographical borders," he said.
"Genealogy becomes a history lesson because once you start looking at these people and the periods of time, you cannot analyze, evaluate or interpret that information if you don't know what's going on at the time they're living," Stieglitz said.
Stieglitz enjoys the process so much, he's studying to become a certified genealogist.
Family trees may be rife with inaccuracies if the family historian is not thorough.
Through his genealogy courses, Stieglitz learned that "there are so many mistakes, so many errors. People are so anxious to find something that they'll just plug it in if it looks right."
He pulled his information off Ancestry.com because people were incorrectly taking his ancestors and putting them on their own family trees.
"There's a real personal side to this. It's not just names and place. It's people that lived and died," he said.
Stieglitz is happy to answer genealogical questions or offer tips. He can be reached at firstname.lastname@example.org.