Why do you have thousands of DNA matches? In this post, learn why so many unfamiliar people appear on your list and whether all are related.
On the day I wrote this article, my DNA match list on Ancestry DNA had grown to 19,428 people – up from 16,885 last time because more individuals appear as matches to me each day.
My list of Ancestry DNA matches, now at 22,885 matches, has become one of my favorite parts of DNA results. There’s so much that can be learned from all these people!
Who are these people on our DNA match list, and do they all belong there?
At first, looking at our DNA matches may seem daunting and bewildering. Although some might recognize a few names on their list, there could be thousands upon thousands more who could potentially be related to us in some way.
Who are these individuals, and why have they all made our DNA match list? Do they all belong there?
Below I will describe why there are thousands of DNA matches.
Why do You have So Many DNA Matches
Simply, having many hundreds, or even tens, of DNA matches could be explained by having many relatives, each sharing genetic material with you. Since so many individuals in the world share genetic material with you and many have tested their genome, the results leave you with an extensive list of matches.
How many relatives does an average person have?
An individual could have up to about 750,000 relatives ranging from close first cousins up to distant eighth cousins; when we count 9th and 10th cousins the numbers rise substantially; up to 20 million potential tenth cousins exist!
Of course, this figure does not account for cousins not directly in our generation, such as third cousins once-removed or sixth cousins twice-removed; nevertheless, we have an incredible array of family members scattered all around the globe.
At least some of our genome is likely shared between first, second and third cousins; as soon as you move further away from these relatives, your chances of sharing DNA decrease considerably.
Though we do not share DNA with all our relatives, most will share at least some with the approximately 750,000 individuals related to us by an 8th cousin or closer relationship. Even though only about.002% of 10th cousins may match on a DNA test, we might still match over 40,000.
As DNA testing grows increasingly popular, so too will our chances of having many genetic relatives increase exponentially. Given that there may also be people on our DNA match list who aren’t actually related (more on this below), it should no longer come as a shock when thousands of names appear on these lists.
All DNA testing companies impose some kind of restriction on our DNA match lists; otherwise we would see every person who shares DNA with us listed. Some services like 23andMe limit the list to certain numbers.
Other companies, like Ancestry DNA, require people who share at least a minimum threshold of shared DNA to be included on your list. Unfortunately, due to not currently setting limits on our DNA match lists and only excluding tiny segments with tiny overlaps when creating them – as AncestryDNA currently hosts over 18 million people in its database – AncestryDNA match lists tend to be quite long.
Are we related to all of our thousands of DNA matches?
While we’re likely related in some way to everyone on our DNA match lists that is estimated as close relatives – such as first, second or third cousins – it is still possible that some may be unrelated. As we move down our lists with smaller amounts of shared DNA with potential matches we become more likely to encounter individuals that share no DNA at all, often known as false matches or “false matches.”
Though my list contains approximately 19,000 individuals, it’s safe to assume I am related to at least half of them even distantly, though some connections might never be discovered by me directly. Furthermore, this may also take into account that some false matches may truly be related to me in at least some manner despite not sharing DNA based on this connection.
There are two types of DNA matches
Our matches share two kinds of identical-by-state and identical-by-descent DNA segments; those passed down from an ancestor will always share an exact match, while identical-by-state segments just happen to share identical sequences.
Therefore, they do not indicate a common ancestor. DNA matches with only one small segment shared between us (such as under 10 centimorgans ), are likely coincidental matches and do not indicate shared ancestry.
Larger segments – even those over 10-20 centimeters long – may also match state by state, increasing the likelihood that any matches could be related genealogically.
So in other words, matches that share multiple segments longer than 10 centimeters are highly likely to be related to us in some way and it is up to us to conduct family tree research to identify our common ancestor.
Conclusion
We hope that this post has provided you with all of the answers to why your DNA match list contains such an immense quantity, sometimes comprising thousands or tens of thousands of matches.
If you have any inquiries or would like to share how many DNA matches there are in your list, I would welcome the discussion below.
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