Using an ethnicity dna test kit, for genealogy and family trees

An ethnicity dna test kit, will normally not do much stuff about your family tree and genealogy.

That is why it is important to know the difference between, an ancestry and ethnicity dna test kit.

An ethnicity dna test kit, just looks for ethnicity.  So says where in the world your ethnicity comes from:

1, Tells you, your percentages of different’ ethnicities

2, Some will also do YDNA and Mt DNA testing.  This can show the geographical journeys your ancient ancestors did throughout thousands of years, since the first human 50 – 60 000 years ago.  So this is about ancient ancestors, not closer relatives.

3, Matching you up to other relatives, that may also have done tests with the same company, so be on their dna database.  This can help you to find missing relatives.   It also predicts how you are related to any people it finds, such as saying second cousin, once removed.   It is an easy way to find relatives and also enables you to find people, where normal genealogy records and documents have come up empty.


Depending on price and what it is about, an ethnicity test kit may only do point 1.

Others cost more and also do point 2. Others also do point 3.  Please see our best ethnicity test kit reviews , to see which ones we like and what features they have.


An ancestry dna test kit though is also about family trees, it can also this point as well:

4, Link up with a family tree records website, that show you your family tree.  That means if it matches you up with another person in their dna database, it can also show you other relatives that are related to that person and yourself.


However even if a person gets a test, just to find their ethnicity and just does point 1 above, it can be useful with regards your closer family tree.


How your ethnicity is spread over your 46 chromosomes, gives a very personal family genetic fingerprint

23andMe do not just show the percentages of ethnicity you have.  They show all 46 chromosome strands that your genes are on.  Then they show where on each chromosome strand, your ethnicities are.

So it shows the unique way your ethnicities are spread over each chromsome.

This means, whereas others just say the percentage of each ethnicity you have.  23andMe also show the places they are on your genes.

This makes you more unique.  As for example, as you have your ethnicities, at a certain places on a chromosome strand, other relatives may have the same.

Then if you know what relatives these came from, this can give you more leads for your investigation.

For example, if a person has Swedish parents, who definitely have close to 100% Scandinavian dna ethnicity.   However if the child’s ethnicity turns out to be just 40% Scandinavian and the chromosomes with the Swedish ethnicity on the chromosomes is just coming from one of two lines in each pair.  Then one of the parents may not be their biological parent.

This is because all chromsome strands are in pairs, one of the pairs comes from the father and the other comes from the mother.  So if the expected ethnicity is just one one of the two chromosome strands, that means the ethnicity is just from one of the two parents.

Then the child can look at the ethnicity on the chromosome lines that are not the Scandinavian ones.  The ethnicity profile on those may be good clues about who their real other parent might be.

So an ethnicity dna test kit, can show that a person’s parents, or one of a person’s parents are not actually their parents.

The unique ethnicity spread on each chromosome strand, is very accurate to what their relatives would be, as it is so unique.   This could help you be sure that a relative, is actually are relative.


Even a basic ethnicity breakdown could help link you to other people

Even if it is a test kit, that just gives the percentage of ethnicity.  It does not show how them how their ethnicity is spread on the different places on their chromosomes.

It is still giving their actual ethnicity percentages, which may be useful on the path to investigating who their real parent is.

For example if they are 40% Scandinavian and 40% Irish.   They know that one of their parents is almost 100% Scandinavian.   Then that may give them another clue about who their other parent may be.

This can also go are far as grandparents as well.

It will of course show if one of their parents, is not their biological parents.

This means that even an ethnicity dna test kit, can start being a fun thing, but can also show serious family information that the test taker did not expect.



Why are my ethnicity dna test kit results, so different to some of my ancestors in my family tree?

Lack of data from some ethnicities and areas

Even with the best ethnicity dna test kit, results come from having done tests with other people from all over the world.

Then they sees how much of your DNA matches, the people they know are from that part of the world.

DNA testing kits are quite new and so there is only so much data.  This limits what can currently be done and means it is not as accurate as we would like.  The results are on average good, but they are improving all the time and there is a way to go.

More people are tested, from different areas and so more results are coming back all the time.  So the results are getting better and better.

If you were go do a test again in at a future time, the results could be slightly different as they are hopefully better.

These are the reasons:

1, Less data from less developed parts of the world

Some parts of the world are not able to access an ethnicity DNA testing kit, or cannot to buy one.  As a result, some companies have sent out DNA testing kits for free to those places, get more data from them.

However although this is getting results, it cannot compare to the massive amounts of data already from wealthy modern areas such as America.  In America, millions of people have already used the best ethnicity dna test kit, as they have lots of access and information.  Also they can afford to do them.


2, Less data from countries the laboratory is further away from

Many of the testing companies are located in America or Western Europe.  As a result they have lots of their data is from these parts of the world.

Sometimes the best data comes from European ancestry because so many people in the West have come from these areas and so there is so much data.  In areas such as the United Kingdom, some companies can break DNA into lots of different parts of the country.

If you are not from European descendent, such as being from Asia or Africa, it is good to have a look at best ethnicity dna test kit recommendations pages, to see which is best for you.  It also says if one has has a special kit for people with ethnicity from those areas.  Also if the company is actively doing samples for free in these areas, to build up their database to do their analysis against.


There are complaints out there from people who have received their test results and it does not make sense when compared to their family tree and history.

They can give good information and interesting results,  but they are only an estimate and we do not recommend seeing them as more than that.


3, Some ancestors genetic data is lost through the generations

The genetic family tree can be different to your genealogical family tree.   At each generation, people get half of their DNA from their mother and half from their father.  So an ancestors DNA is reduced, as it is passed down with each further generation.

After a few generations, an ancestor’s ethnicity DNA may not even be seen by a DNA test.

People often know their history through their genealogical family tree. This is what is known from family stories, records, events and so on.

So this is different from your genetic tree, as less and less genes are passed down with each generation.  Also different genes are passed down to different children and so on.

There could be a very well known family descendent who is of Chinese ethnicity, in a family that is mostly western.  As a result of this person being a very active and respected member of the family, the family sees itself as having a very strong Chinese ethnicity. However this Chinese ancestor’s DNA has been very diluted over each generation and the DNA that the test taker got, does not have much of this ancestor’s DNA.  As a result the test taker sees even from the best ethnicity DNA test kit, that they have very little or no Chinese ancestry.

Interestingly you cannot tell which ancestor’s DNA will be passed down.  As a result you cannot tell what will be found in your DNA.  This of course makes things even more interesting, when you get your test results back.

4, If the best ethnicity dna test kit,  does YDNA and MtDNA testing, you could get more results back

If this Chinese ancestor was your father’s father, or your father’s father’s father, or even much further away on your father’s line.  Also if the test kit you used included YDNA testing.  Then his ethnicity would still pick up and be very strong in your DNA.

Also if this Chinese ancestor was your mothers or father’s mother, or their mother’s mother, or mother’s mother’s mother, or somewhere even further on that maternal line.    Also if the test company you used does MtDNA testing to pick that up.  Then this Chinese ancestor would be picked up in a strong way.

However these YDNA and MtDNa each do single lines going back through history, so the chances of getting this person is quite low.  It means that each test only looks at only person in each generation.

For example, once you go back to 10 generations, there are 1024 ancestors in that generation.

So if the test is picking up this person who is very different to your general ethnicity,  this also means the test could exaggerate your ethnicity to being more this ancestor.


5, Lies in the family trees

This is a big one.  It can be fun to have an ethnicity test, but it can also show up lies in the family history.  There can also be a lot of them and things you never expected.  The lovely uncle who actually had an affair.

It is well known for people to find that half of their ethnicity is not what it should be.  Amazingly this can happen when a person is older and their grandparents and parents have passed away.