This pack is designed to assist you if you are currently considering a DNA test, or if you have received the results of a DNA test, but don’t really know where to go from there.
The first thing to note is that there are 3 main types of DNA test, and which one you choose, depends on what you are looking for. The most common (and cheapest) test is autosomal DNA. Essentially, this just means you are testing DNA from all 23 chromosomes, which you have inherited from ALL your ancestors. These tests are marketed mainly to show your origins / ethnicity.
In this test, your DNA is compared to the DNA from reference populations that each testing company has developed.
To make their reference populations, DNA companies find people whose ancestry comes from a single location and avoid including individuals whose ancestry comes from several different geographies. The initial criteria generally used to identify candidates for a reference panel is that all four grandparents originate from the same non-colonial geography (not USA, Australia, etc). DNA companies also survey participants for trans-national identifications that are important for distinct ethnicities that can form their own genetic populations separate from geography of origin (i.e., Ashkenazi Jewish, Cherokee, Basque and others). As each company has their own reference panels, results may differ depending on whether your test is from Ancestry, FamilyTree DNA, 23&Me etc. Also, these reference panels are continually being updated and getting more granular as new distinct ancestral populations are being described, so your ethnicity results may change over time as new updates are released.
An example of the ethnicity results for the same person in 2018 and 2020 after an update to the Ancestry DNA reference populations, compared to their results from FamilyTree DNA. Earlier Ancestry results had a lot more less-specific results, but as more accurate reference databases are developed, the results are more granular and low confidence regions may be excluded. If you do a test now, you will get a refreshed set of results every time the reference databases are updated.
As you can see from the FamilyTree DNA report, the results are different …. Some of the difference can be explained by different regional definitions, but ultimately it all depends on each companies reference databases.
The most common test
This is the most popular type of DNA test that many companies are offering at a cost of about USD 80 – 120. It is worth waiting for sales around mothers day, fathers day, thanksgiving, christmas etc. as there are often 20% discounts around these times.
The attraction of the autosomal DNA test is that it can be taken by males and females and that it tests all ancestral lines and can reveal relationships within a fairly recent timespan of around the last two hundred years. At present, this test seeks to report results back to around 5 generations with confidence. Matches are usually reported in ranges such as 2nd to 3rd cousins, 4th to 5th cousins, greater than 5th cousins. These results may help you to investigate unknown relatives and reveal information about branches of your family which you have been unable to trace using documentary sources alone. If you’re interested in learning more about your ethnicity, and finding or tracking down lost or unknown relatives, then this is the test for you.
Standard Autosomal test
For the autosomal DNA test, ALL your relatives contribute to your DNA that is analysed by this test. In this example Jeff Matthews DNA has contributions from everyone on this tree. Obviously he shares more with his parents, George & Marion (about 50%) than with William Stevens and Rebecca Murray (his 2nd GG grandparents (about 6%)
FamilyTree DNA also do an additional analysis of your matches based on shared DNA from the X-chromosomes. Because males only inherit an X chromosome from their mothers, if a male has an X-match in his DNA results, the shared ancestor must be on an ancestral line that follows the female X-inheritance pattern, as above. In the example, Archibald Wilson gets his single X chromosome from his mother Alice, and only received a Y-chromosome from his father Geoffrey Wilson. Therefore any of Jeff’s DNA matches that share DNA from the X chromosome could not be from his father, or great grandfather, Geoffrey Wilson’s line. Even though Ancestry DNA does not do this analysis, you are able to import your DNA from an Ancestry test to FamilyTree DNA to see these results
With the autosomal DNA test, you also receive a list of your DNA matches based on the about of DNA you share with other people who have done the test.
This list will obviously be biased by the countries in which the test is available, and the number of people who have taken a test. The good thing is, that once you have taken a test, new matches are added to your list continually, so even if you have very few matches when you first get results, these are constantly updated.
A likely relationship to you is estimated based on the amount of DNA shared (measured in centimorgans (cM). On average, you share about 3485cM with a parent, 2613cM with a sibling, 1754cM with a grandparent, 866cM with a first cousin etc. The relationships mentioned on the report are just an example of what the link could be, but we can help explore other possibilities.
You can also find out which of your matches are shared with other matches, so if you recognise one of your matches, or can persuade another relative to also do a test, this will enable you to work out if a match is on the maternal or paternal side ….. or even a particular branch of the family and Ancestry provides some useful tools to allow you to create your own categories and groupings to organise your matches.
If you have an online family tree with Ancestry, it will also compare the trees uploaded by your matches with your own tree and see if there are any overlaps. This is an incredibly useful tool that allows you to not only grow your own tree, but also to accurately identify where your DNA matches fit. We can certainly help you get stared with this analysis.
DNA inherited from father to son
The Y-DNA test is completely different in that it only tests DNA from the Y chromosome, which only males have.
Females can therefore not do this test, but can get a brother or father to take the test in order to determine details of their paternal ancestry.
The major difference between the Y-DNA test and the autosomal DNA test is that the Y-DNA test gives information about your deep paternal ancestry going back tens to hundreds of thousands of years back. As females do not have a Y-chromosome, and exact copy of the Y-chromosome is passed down from father to son, unlike any of the other 22 chromosomes which are a mixture of the mothers and fathers DNA, and thus gets diluted every generation.
On average, every 140 years or so a single mutation occurs in the Y-chromosome, and this mutation is then inherited by all future sons. Using this information, we can trace DNA back to a single common shared ancestor from Africa about 240,000 years ago.
This ancestor’s (known as Y-Adam) sons’ migrated in small groups out of Africa, and their sons picked up new mutations on the way leading to many distinct DNA signatures. These are known as haplogroups and can be identified by this Y-DNA test. Depending on which haplogroup you are, you can trace your paternal ancestors journey out of Africa to the present day.
The cost of this test depends on the level of detail you get. The cheapest one is about USD 120 and measures 37 short term repeats (STR), which are repeating sequences of DNA that are inherited from father to son. At a particular spot on the Y-chromosome, one man may have 14 of these repeating sequences, whereas someone else may have only 8. Much like a 37 digit PIN code, this can identify which of the major haplogroup branches your ancestors followed up until about 10-15,000 years ago.
You can pay slightly more to have more STRs tested, eg. 67 STRs and up to 110 STR’s which costs about USD 250 which will give additional detail up to about 3000 -5000 years ago, and finally the most comprehensive BigY-700 test, which tests 700 STR’s as well over 200,000 SNP’s (single nucleotide polymorphisms), which are point mutations in specific locations on the Y chromosome, which can provide details of unique mutations up until the the present day. You could be one of a handful of men with a unique SNP signature. This test costs about USD 500.
For the Y-DNA test, only your paternal relatives contribute to your DNA that is analysed by this test.
In this example Jeff Matthews DNA has contributions from his father, grandfather, great grandfather, and great-great grandfather. The amount of DNA shared at each generation is also not diluted as the Y-chromosome is inherited intact from father to son.
The journey of the R haplogroup fathers into Western Europe.
The ancestors of the present day R haplogroup originated from Haplogroup P. It is estimated that a particular mutation occurred in central Asia about 27,000 years ago which led to the formation of the R haplogroup. All current R haplogroup males carry this mutation. While individuals with this original R group are quite rare, it did split into 2 major subclades which migrated and expanded rapidly into Western Europe, and another sub group which migrated to India.
The R-M343 (also known as R1b) is the most common subclade in Western Europe, and originated about 18,500 years ago. For instance, the modern incidence of R-M343 (R1b) reaches between 60% and 90% of the male population in most parts of Spain, Portugal, France, Britain and Ireland.
The Big Y-700
The results of my own Big Y-700 test which show the route my paternal ancestors took to arrive in England between 1300BC and 1600 AD. In addition to this information, the Big-Y test also identifies any unique mutations (SNP’s) you have which are not shared by other named haplogroup subclades. In the block chart below, I have only 1 match (my son) who is in exactly the same subclade as myself, but I also have some close paternal relatives with the surname, Hadley, Purnell & Daniel. We would have shared a paternal ancestor sometime before 1600, when my particular subclade originated. As more people (and more closer relatives get tested, this information will get more granular).
In addition you can join a surname project, which aims to determine how all the different clans with the same surname are connected to each other. Many testers in the US with extensive post immigration (to the US) documented family trees are part of these projects, attempting to find which families that remained behind in Europe their particular clan is linked to. In the above table, the numbers are the number of STR’s (short term repeats) at 20 of the (up to 200 STRs) that are analysed. Much like an individual PIN code that has been used to group people with the same surname and very similar PIN codes into the same clan.
Mitochondrial DNA (MtDNA)
DNA inherited from mother to children
In much the same way as Y-DNA is inherited intact from fathers to sons, Mitochondrial DNA is inherited intact from mothers to their children (sons and daughters), however only daughters can pass this Mt-DNA on to the next generation. Whereas Y-DNA is from the nucleus of the cell and part of one of our set of 23 chromosomes; mitochondrial DNA is present in cell mitochondria of a woman’s egg cell, and thus gets passed on to all of her children. There is no male contribution to this genetic material.
In the same way as you can trace the journey of your fathers fathers father with a Y-DNA test, you can trace the journey of your mother’s mother’s mother …. This test costs about USD 160.
The results of my own Mt-DNA test which show the route my maternal ancestors took to arrive in Europe about 5,800 years ago. Mutations do not occur as frequently in mitochondrial DNA as in nuclear Y-DNA, so the results are not as granular. This is the path of mitochondrial haplogroup ‘H’, known as ‘Helena’ in Bryan Sykes’ 2001 book, ‘The Seven Daughters of Eve’.
The Seven Daughters of Eve
This book by Bryan Sykes, professor of human genetics at the University of Oxford, draws on recent research into mitochondrial DNA, and the classification of living humans into maternal lineages characterized by specific shared mutations in their mt-DNA. He identified seven major mitochondrial lineages in Europe, and brought this work to life by giving a name and biography to each of the presumed ‘clan mothers’ of these lineages, or Seven daughters of Eve. Thus we have chapters on Ursula, Xenia, Helena, Velda, Tara, Katrine, and Jasmine, with sentimental descriptions of their imagined lives.
For the mt-DNA test, only your maternal relatives contribute to DNA that is analysed by this test. In this example Jeff Matthews mt-DNA has contributions from his mother, grandmother, great grandmother, and great-great grandmother. The amount of mt-DNA shared at each generation is also not diluted as the mitochondria are passed on intact from mother to all her children, but only her daughters can pass it on to the next generation.