This blog post will explore some of the types of DNA testing that are available and how they may help in your quest for building your family tree, finding answers to a genealogical question, or locating that “missing” person in your biological family tree.
It is meant to explain, in a very rudimentary fashion, some information about a few DNA test types and how each one may help you.
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KNOW WHAT DNA TESTING INVOLVES
Genetic testing, also known as DNA testing, involves obtaining DNA from a sample of cells in your body to identify specific genes, chromosomes, or proteins, including those that are faulty (known as mutations). The test can be used to help identify genetic lineage, confirm, or rule out an inherited genetic disorder, assess your risk of developing or passing on a genetic disorder, and select which drugs may be most effective based on your genetic profile. Several hundred genetic tests are currently available, with many more being developed. The tests can be performed on blood, urine, saliva, body tissues, bone, or hair.
The DNA tests I will be discussing in this blog are used mostly for genetic lineage.
With the permission of their customers, many DNA testing companies store DNA data from thousands or millions of customers. By matching your DNA against the DNA patterns of all those other DNA test participants, some DNA companies can tell if you share unique sequences, essentially proving that you share ancestors somewhere in your family history.
That opens one of the biggest services offered by DNA testing providers: Helping you understand your family tree, the migration patterns of your ancestors, and even in identifying relatives you never knew you had.
DNA testing has been advantageous in helping to solve some high-profile cold cases for law enforcement. For instance, The Golden State Killer cold case solved through the assistance of CeCe Moore, a genetic genealogist. Throughout the last decade, CeCe has been considered an innovator and pioneer in the use of autosomal DNA to resolve unknown parentage and family mysteries, frequently consulted by DNA testing companies, genealogists, adoptees, law enforcement and the press.
BE AWARE THERE IS A DARK SIDE TO DNA TESTING
You may need to consider the privacy implications. Your DNA is fundamentally, the source code to….you. If DNA companies are sharing that code, whether with law enforcement or with other companies it can be little unsettling. If you authorized that sharing, its one thing, but if your family member or cousin authorized sharing their DNA, they have also, essentially, allowed a considerable amount of your DNA to be shared. And that doesn’t even include what happens if your testing service provider gets hacked.
The other issue is for those folks who took DNA tests and received back results they didn’t expect. There are many issues involved with this, from what is called “misattributed paternity”, to issues of race, what you have been told as part of your family history, and disturbing discoveries about your family tree. Keep these unexpected consequences in mind if you decide to move forward to do DNA testing. Always be prepared for the unexpected.
ADVANTAGES TO USING DNA
When used in genealogical research, DNA offers several advantages over documentary evidence. Documents may contain untruths. These could arise because an informant lied or did not have the correct information, because a transcriber misheard information, erred in recoding it, or because of some other error or intentional act. In contrast, if DNA evidence is correctly interpreted, it does not contain untruths.
In other words, DNA doesn’t lie, people do.
Among the main advantages of using DNA evidence are that DNA can:
· Justify documentary research
· Provide clues to guide documentary research
· Yield evidence where no know documents exist
DNA is not useful in solving every genealogical problem. The types of genealogical questions for which it can provide evidence are generally:
· Locating potential biological relationships for adoptees
· To substantiate a hypothesis where documentary research alone has not provided a clear answer
· By itself, DNA evidence can give a clear indication of a parent-child or sibling relationship
· For all other relationships, DNA evidence must be associated with documentary evidence to reach a plausible conclusion
All genealogical sources, including DNA, have the potential to reveal unexpected relationships or the lack of an expected relationship. We must anticipate these possibilities and consider the potential emotions and reactions of all involved. Ethics should guide us as to what should be revealed, to whom it should be revealed, and how it should be revealed.
KNOW HOW TO CHOOSE A DNA TESTING SERVICE
To help navigate through the offerings of various DNA testing services, here is a website guide for your assistance.
If you are looking for family information, the bigger the database, the better the chance that you will find long-lost family members.
When it comes to health and lifestyle information, the DNA tests use some of the same information. This is really a matching process, but instead of looking for family members, the test provider looks for matching characteristics, particularly genetic markers for certain diseases and traits.
KNOW THE LIMITS OF DNA MATCHING
Our chromosomes not only contain certain code for genetic characteristics, but they also contain something of a genetic fingerprint of the parents of each child. That is why two siblings, born of the same two parents, will share a considerable amount of chromosomal data.
Cousins, too, share chromosomal date, just not as much. The fingerprint has in effect been diluted. As you move back in time to grandparents, great-grandparents, and great-great-grandparents, and then down other branches of the tree to first cousins, second cousins, third cousins, fourth cousins, and so on, less, and less of the DNA sequences will match.
The reason you need to understand a bit about chromosomes is that you are about to decide: Which test type do you choose?
UNDERSTAND THE TEST TYPES
Autosomal DNA (atDNA) testing – this type of testing is commonly used for ancestral genetic information. These tests can usually reveal quality genetic information going back four or five generations. A child’s genome is the same size as each of his or her parents’ genomes, a child can inherit only 50% of each parent’s total DNA. Beyond the parents, a child will inherit a variable amount of DNA from each individual in a given generation. Therefore, a child receives an average of 25% of his or her DNA from each of the four grandparents.
Y-DNA testing – this Y-DNA test can only be administered to men, and traces DNA back through the patrilineal ancestry. This is basically from father to grandfather to great-grandfather and so on.
mtDNA testing – the mtDNA is matrilineal and lets you trace your ancestry back through your mother, her mother, and her mother going back. A female passes her mtDNA to all of her children, but a male does not pass mtDNA to his children.
Having the same DNA footprint passed down for many generations is a major advantage when trying to determine if a matrilineal line was of a specific bio-geographical origin, such as African or Native American.
The same characteristics that make mtDNA useful in some situations make it difficult to work with others. For example, it is impossible to determine which of a woman’s daughters or granddaughters is the ancestor of a particular line of descendants.
Three of the major autosomal or atDNA testing companies are 23andMe, Ancestry DNA, and Family Tree DNA. Note that there are hundreds of other DNA tests offered by other companies. Each have their own advantages in their results.
For instance, 23andMe creates a “DNA Relatives” list for the test taker, AncestryDNA matches are called “DNA Matches,” and Family Tree DNA identifies genetic matches as simply “Matches.”
So, what is the best DNA test for you to take?
The answer to that depends upon what the user wishes to determine about their family tree, ethnicity, and DNA relationships.
If I had to choose one type of test to begin the journey into DNA testing it would be an autosomal DNA (atDNA) test. Most people are interested in their ethnicity and the geographical regions from which their ancestors came within the last several hundred years.
If, however, one seeks to find a biological parent or child, it may be advantageous to start with the autosomal DNA testing and move on to Y-DNA or mtDNA testing in order to narrow down the list prospective relatives if the atDNA does not produce a close match.
The Ten Best DNA Kits for 2021 are linked here.
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