27 May 2013

It's a Mad World

My tree

I love graphics. It's easier to explain complicated issues to others with a graphic or two. It's easier to understand them yourself! Sometimes, a good graphic can show you what you're missing. And what we're missing can hurt our research... To the right is my pedigree chart from Ancestry.com. The pink line is my direct maternal line. I am a female, so I can take the mtDNA test and learn about those women back through time immemorial. Unfortunately, I don't have the ability to take the Y Chromosome test (not having a Y chromosome and all), so I've "nulled" my direct paternal line. To find out about those people specifically, I'd need my brother or father to test. But what about everyone in the green section? Every generation back is just going to add more people that the DNA test doesn't find. Suddenly, my maternal line is a small and lonely fraction of what I am.......


Jim's tree
My brother's pedigree chart is a bit more encouraging. He gets the pink line for the mtDNA test. He also gets a blue line for the Y Chromosome test. But that blasted green section! He's still only going to give us a small view of the information now available. What to do? Have no fear, Autosomal DNA is here! Remember, there are 23 chromosome pairs. You inherit one chromosome from each parent for each pair. There is one pair known as the sex chromosomes, and that's where we get the Y Chromosome test. The other 22 pairs are known as the autosomal chromosomes. These are the building blocks of all that we are. And in them is the information of a million lifetimes.


Nationality
An Autosomal test is sometimes referred to as an Ethnicity test. Now, I've covered the complications of race and ethnicity before, but we're going to cover it again in a different way to help those who need it. Nationality is not ethnicity. Your nationality is where you were born or where you took the oath of citizenship. I'm an American, born and raised in the United States. As you can see in the graphic on the right, so is most of my family. The black boxes are for the unknowns. My grandfather Gibson is illegitimate, so I have no idea about his father. My great grandmother Goff/Gaulf is a bit of a mystery to me. I am not certain of her parentage, although several trees on Ancestry.com are. So I am going to play it safe and say I don't know her parents' nationality either. My great grandmother Lavinski was born in Scotland, and her parents were Lithuanian. When I take the Autosomal DNA test, if I were to mistake nationality with ethnicity, I would expect my pie to be mostly American, with a small portion set out for British and Lithuanian. Now, there's already one problem: American, British and Lithuanian aren't ethnicity options!


Heritage
Some people confuse heritage with ethnicity. I changed up my graph. I know my grandpa Gibson is half English based on my research of his maternal line going back about 8 generations. I know my grandma was part German, part Irish and part Native American based on research and rumor (I used grey for the rumor). I know my grandpa Householder was part German and part Native American all based on provable research (I used the U.S. flag for the provable Native American heritage). My grandma Brown was part English and part Lithuanian. Note that my great grandma Lavinski has half the British flag and half the Lithuanian flag. She identified herself as Scottish for as long as I knew her. She was born and raised there. For a long time, all I knew about her was that she was Scottish. Lithuania was in her blood, but Scotland was her heart. So my square becomes a jumble of flags, cultural identities, and general confusion. If I took the autosomal test and confused heritage with ethnicity, I would expect to find Native American, German, British, and Lithuanian. But those still aren't ethnicity categories I'm going to find!
 
So what is ethnicity? When it comes to an autosomal DNA test, it's something deeper than a flag. Something richer than a culture. And something untold by written history. Since ethnicity is so enormous and far reaching, let's warm up our brains with an exercise on a smaller scale. Think of your house. More precisely, the land your house is on. Is there a fence to clearly define the border between your yard and the neighbor? Who placed the fence? Is it your fence or theirs? How long has that fence been there? Imagine your surprise if you were to get the land deed from the county office and find out that fence was on the wrong line. How were you to know? The "real" border is an imaginary line based on land markers and a general agreement between who sold the property and the buyer. That seller had a larger parcel of property that encompassed your house and your neighbor 50 years ago. He bought half your property from someone else. So straight down the middle of your house is another imaginary line from that older property marker. 100 years before that, your property was part of the U.S. government's purchase from France or Spain. 1,000 years before that, it was in the hands of this Native tribe or that. 1,000 years before that, it was used by a different tribe or another. 10,0000 years before that...........
 
That imaginary boundary has been jumping around quite a bit and for longer than you'll be able to find a paper trail to account for. And that is exactly what the problem is with defining ethnicity for the purposes of genetic genealogy. So how do the researchers define it so they can make tests for us? Well, they make reference populations and complicated math. What is a reference population? They find a living person with proven heritage of one area, say, Lithuania. They test the person's DNA and compare it to others who claim to be 100% Lithuanian and then compare those against folks who are 100% Nigerian, Chinese, French, Russian, Australian Aborigine, etc. The markers that are shared by the Lithuanians but not the other groups are chosen to mean "Lithuanian". But the borders of Lithuania have been fluid and Lithuanians have a shared cultural history with eastern Russia, Poland and the Caucasus. So instead of calling the ethnicity "Lithuanian", the scientists call it "Eastern European" or "Caucasian" or "North East European" or whatever. The names are an arbitrary label placed by the scientist based on the number of different reference populations they sample and what imaginary borders they place on the world to mark one from the other. Genetically, humans are not far enough apart to be so delineated.
 
When I first heard of autosomal testing, there was something about German heritage being impossible to define. Germany is in the center of Europe. It has conquered and been conquered over and over again since the earliest Germanic tribes. The Celtic culture that many will associate with Ireland, Wales or Scotland is based on the Celtic tribe that conquered the original peoples. The Celts came from the area we now call Germany. There were several tribes from Germany that pushed into different areas surrounding them, leaving a genetic signature along the way. In the early days, the reference populations weren't large enough (or clearly defined enough) to say "this is German, this is British, this is French and this is Scandinavian". They really still aren't. But the companies you can test with do their best and are getting better. So when you take a test now, your ethnicity percentages may change later. You don't change, but the science improves. So you expect British and get a lot of Scandinavian. A year from now, those populations could be better defined and the Scandinavian will reduce. So what to do? Patience, my friend, patience.
 
And you'll need a lot of patience, because to best utilize the DNA test, you'll need to read and research. DNA tests are of no use without real genealogical research. And not just the "add it because everyone's tree has it". No "I'm just having fun" research. Real "here's the hundreds of hours spent squinting at pieces of paper to prove this person is my relative vs. that other person with the same name" research. Documented, cited, and oft times not found online research. Also, DNA tests are useless without knowledge about the tests themselves and the companies behind them. These posts I'm writing are just a starting point. How deep you dive into your genetic past is dependent upon how much time you research this technology. Join DNA discussion boards and groups. Watch videos. Read, read, read.
 
What Companies Test Ethnicity?
 
National Geographic and Family Tree DNA are again a part of the list. We also add 23andMe.com and Ancestry.com. Again, there are several others, but these are the known, trusted, most used ones. I will be reviewing the companies and the third-party tools that make testing useful in upcoming posts. There is so much to read today (and so much when I write about the companies themselves), that I don't want to go too deep into the company part right now.
 
Caveats
1. Ethnicity is region specific, not country or town specific. It will not tell you what tribe of Native American or African you come from. Even if the reference population is from Italy, your relatives may not have been Italian. The regions you know are little imaginary lines, not real facts.
 
2. Ethnicity is not parent specific. You will not be able to tell what part of your ethnicity is your father and what part is your mother based on your test. Research and comparison with other tests will help, but again, this test will not tell you who your real father is. And thanks to pedigree collapse, your parents will share an ancestor or two. So some matches will be related to both sides of your family. Researching the differences between the cousins you know are exclusive to one side and cousins you aren't so sure of will help you complete the picture.
 
3. Reference populations have grown, but they are still small and based on what people "know" about themselves. As people take this test, their results will help to refine the ethnicity definitions. It's not an overnight thing, however. (Ancestry.com has an alarmingly high Scandinavian error right now that people seem to expect to be "fixed" within weeks. The test is only a year old and it can take a year or more before they can clearly define the margin of error and filter out the incorrect Scandinavian results. I'll discuss this more in the upcoming AncestryDNA post). National Geographic has been doing this for quite a while as a research study. They travel to test isolated portions of the world to better refine the results. Their goal is to test as many people as possible to fully map the migration of man...........talk about a Herculean task!
 
4. A well-researched tree is necessary. Documented lines for every grandparent, great grandparent, 2nd great grandparent, etc. for 10 generations is best. Very few people have every single person for 10 generations proven and documented, so you will have holes. Your matches may fit in those holes, so don't give up just because you don't see a matching relative easily. They may hold the clues to your greatest mysteries, but you'll have to work together to solve them. And researching your collateral lines (the siblings of your grandparents, great grandparents, etc. down to the last known generation) will help match your distant cousins. Remember, a 1st cousin is related to you by 1 of your 2 parents; 2nd cousins by 1 of your 4 grandparents; 3rd cousins by 1 of your 8 great grandparents; 4th cousins by 1 of your 16 great great grandparents...... do you know all the great grandchildren of all 16 great great grandparents? Do you know all 16 great great grandparents?
 
5. DNA is more than 10 generations. You could show an ethnicity that doesn't make sense based on your detailed research. It could be an error, but it's just as likely that it's from an ancestor that lived before written history. You could be seeing the last remnants of your 45th grandfather Oook. How do you know? That's right, detailed and thorough research.
 
6. DNA can disappear. Statistically, you'll share 50% of your DNA with each of your parents. 25% will be shared with your grandparents, and 12.5% with each great grandparent. Thanks to insertion, translocation, deletion and other genetic shuffling, what you share in reality can be a little different than the statistics. Naturally, you'll share 50% with your dad, but during meiosis (the creation of sperm) he may only give you his mother's chromosomes. You could have 0% of your grandfather's ethnicity markers! And that's only your grandfather; what if you're hoping this test will carry the ethnicity of your great great grandparents? You could easily have missed out on their 6.25% contribution! Unfortunately, this means that you may not show that Native American you were desperate to prove. It may mean you missed the markers. A well-researched tree will help. You can compare your results to that of the cousins you'll find and maybe their well-researched tree will have the documentation proving your heritage (or just as likely disproving it).
 
7. DNA doesn't lie. The companies that test you don't choose your matches based on your tree or your surname. They may match you differently based on what they consider a margin of error or a minimum percent to be considered a true match, but the people they say are your cousins are your cousin. Pedigree collapse could effect the generations calculator, so don't trust that the prediction of 4th cousin is accurate. They could be a little closer or farther depending on how often the family intermarried. Proper genealogy research will help. Since DNA doesn't lie, it could tell you something surprising about yourself. Even though this isn't a test specific to your father's line, you could prove a non-paternity event or adoption simply by what cousins you match. If learning your family isn't blood related will change how you feel about them, DO NOT TAKE THIS TEST. If finding a large percentage of an ethnicity other than you expect will change your personal identity, DO NOT TAKE THIS TEST.
 
8. There's still a lot of confusion about how genetic genealogy can help/hurt us. You'll need to read, watch, listen............ research. It can be overwhelming. I seriously thought my brain would explode. Take it slow. Don't take everything literally until you've played with it for a while. Know that everyone knows just enough to hurt themselves. Few people are expert enough to give you clear answers. Most groups you can join to discuss DNA for genealogy purposes are started and maintained by enthusiasts just like you, not scientists who run the labs.
 
Now, I think I need to shut off my brain and take a nap. Get your own pillow.
-Ana

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