There is one thing that mothers pass down that fathers do not. Mitochondria. What is it? Inside every cell are these energy producers known as mitochondria. They have their own DNA, which suggests that this organelle may have been a bacteria that evolved to live in our cells. The great thing about the mitochondria having it's own DNA is that it has specific mutations. And because a mother passes down her mitochondria (the father's sperm cells have them, but they are dissolved during fertilization of the egg), this is our best bet for knowing about our mother's direct maternal line. Now, there are exceptions to this rule. Very rarely a man will pass his mitochondria down rather than the woman. Because it does happen, there is some pushback on how accurate we can consider this test. However it's so rare that most people don't worry about it.
Just like "Y Chromosome Adam", there is a "Mitochondrial Eve". Eve lived approximately 200,000 years ago and is the MRCA (Most Common Recent Ancestor) of every living human (on their mother's side). As Eve had daughters, the mitochondria changed and mutated. The mutations are now used to know what branch of the family tree is yours and how you connect to humanity as a whole. MtDNA uses SNPs (Single Nucleotide Polymorphisms), so the results are considered more "ancient". The fact that mtDNA isn't as accurate for recent generations is used by detractors more than the whole "men can sometimes pass down their mtDNA instead of women" thing. But this one's a little harder to refute. I would like to point out that currently it's considered the most accurate matrilineal test we have AND that no test is really useful without real genealogical research to back it up. So don't neglect your documentation just because you take a DNA test!
|A mother passes down her mtDNA to all children.|
So what companies will you be able to get the test from? Just like the Y Chromosome test, the big two are Family Tree DNA (Ftdna.com) and National Geographic. Family Tree DNA is having a sale right now for either introductory Y Chromosome or mtDNA testing for only $49. These are introductory, so they aren't really "useful" to your genealogical research. However, if you have an elderly relative you are worried will pass away before you can afford to get the more detailed tests, this is the perfect way to "save" their DNA for later. FTDNA stores their sample for retesting for years. And you don't have to buy both tests for your male relatives. You will be able to upgrade the Y Chromosome test to a combo test later without having to purchase the separate mtDNA test now. National Geographic is $200 whether you are male or female. Men will get the added bonus of Y Chromosome testing, but both men and women get mtDNA and autosomal testing. There are of course other sites and companies, but these are the most recognised.
|An mtDNA test is just like the Y-Chromosome inasmuch as it only traces one direct line (in this case, your mother's mother's mother etc.)|
1. This test is considered more accurate for your deep maternal ancestry rather than the recent stuff. It can help you find your mother, but only in conjunction with real research. Even the "Full Maternal DNA" test provided by Family Tree DNA can only get within 9 generations (while a Y Chromosome test at 111 markers can get as close as 4).
2. Because you may need to test another person, be ready to answer questions by doing a lot of research. Be able to tell that other person what company you are using. What the results may show. How they will participate (most tests require the subject not eat or drink before giving a sample). What the realistic turnaround time is. How you will use their results: Do you want to make them public so you can connect to living relatives or will you keep them private and are only satisfying your own curiosity. The more you know before you ask for their help, the more likely they will help.
3. The number of markers matters. An introductory mtDNA test from Family Tree DNA will only get you within the last 28 generations.
4. And more markers means more money. Even at the "high" prices, however, I'd like to point out how affordable DNA research has become in less than 20 years. We couldn't even dream of something like this a mere two decades ago. Be thankful that it costs as little as it does.
5. DNA test are non-refundable. Notice I used red, underlined and italicised bold-faced large font "non-refundable". If you don't like the results, tough tits. The labs aren't out to get you, that's your DNA.