Specialised DNA Tests
These tests are designed to answer specific quesions about paternal or maternal ancestry. While autosomal DNA tests are useful for analysing more recent ancestry, these tests provide answers as to your deep paternal or maternal ancestry from thousands of years ago.
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.