With mtDNA analysis, scientists have been able to trace the migration routes of humans over the last 150,000 years or so.
Similar to what has been done with mtDNA, scientists have also developed Y-DNA analysis and have traced it's migration routes.
DNA & Genetics
A relatively new technology for genealogists is the analysis of mitochondrial DNA (mtDNA) and Y-chromosome DNA. Mitochondrial DNA is only passed down via the maternal lines, and Y-chromosomes are only found in males and are passed down via the paternal lines. There are now new tools and analysis that is being developed that allow genealogists to better understand their genealogical roots at a much longer time scale (thousands or tens of thousands of years rather than hundreds of years.)
This is a summary of the haplogroups in my family tree, based on what I know today.
mtDNA tests - my mtDNA (as well as my mother's)
My mtDNA has been tested at FamilytreeDNA and 23andme. My mtDNA was classified as being an H13a1a1a haplogroup subclade.
Haplogroup H is the most common mtDNA category in Europe - half of the people in Europe are of this haplogroup. Because this group is so large, it has been broken down into subgroups, which are shown here.
Marjory Ann (Bair) Donofrio, Eldora Clara (Lange) Bair, Henrietta (Kiesow) Lange, Caroline Friedericke Wilhelmine (Neitzel) Kiesow, and Charlotte Neitzel all have passed down H13a1a1a haplogroup mtDNA.
mtDNA map of haplogroup migration This map shows the migration patterns of the various mtDNA haplogroups. Note the H is represented in northern Europe as expected. H is the most common haplogroup in Europe.
This shows the original location of the H haplogroup is northern Europe. Source: Eupedia.
mtDNA tests - my father's mtDNA
My father's mtDNA has been analyzed, and was classified as being an U1a1 haplogroup. People who are in Haplogroup U descend from a woman who lived around 55,000 years ago. Haplogroup U1 seems to appear mostly in the Middle East, however low frequency results appear scattered throughout Europe, particularly in the Mediterranean. U1a in particular is found from India to Europe, but is extremely rare among the northern and Atlantic fringes of Europe including the British Isles and Scandinavia. Several examples in Tuscany have been noted. In India U1a has been found in the Kerala region and the west.
Y chromosome tests - my Y-DNA (as well as my father's)
I have been tested at FamilytreeDNA and 23andme. My Y-DNA is categorized as "R-L295", also knows as "R2a1", which is not very common. Haplogroup R2 is believed to have originated 25,000 years ago in Central Asia, and its members settled in the Indian subcontinent. Additional information on R2 can be found in the paper by Jean-Gregoire Manoukian.
This shows the spatial distribution of the R2 haplogroup in India.
Source: PNAS.org. A prehistory of Indian Y chromosomes: Evaluating demic diffusion scenarios
Sahoo et al.
Y chromosome tests - my maternal grandfather's Y-DNA
My maternal uncle also has had his DNA tested at 23andme. This gives us the Y-DNA haplogroup for that side of the family (Bair). The haplogroup is R-M335, which is also known as R1b1b2a1a.
My Autosomal DNA
My autosomal DNA has been tested at FamilytreeDNA, 23andme, AncestryDNA, and Full Genomes Corporation (full sequencing in work as of August 2014).
This shows my chromosome segments with my parents, my uncle and my second cousin.
For more information:
The National Geographic Genographic Project provides a good overview of the various genetic markers and where and when they first appeared. This web site shows a detailed atlas of the genetic markers.
There are a number of genetic databases that are online. Mitosearch.org is one which can be used to search for similar mtDNA results, and Ysearch.org can be used for finding people with similar Y-DNA. These people are often referred to as "genetic cousins."
Some Diagrams of DNA
Here's some diagrams which may help in better understanding some of the terms involved in DNA analysis:
Structure of a human cell. Note that there is a nucleus, which contains the 23 chromosomes (the "nuclear DNA" which includes the Y chromosome). These are long strands of double helix DNA that are connected at a point, which makes them look like a small "X".
Also note on this picture the mitochondria (of which there are thousands in a single cell). These contain the mitochondrial DNA. These are very small circular "o" shaped pieces of DNA.
Humans have 23 chromosomes. This set of 23 chromosomes is called a "karyotype."
Actual image of chromosomes.
DNA is comprised of 4 genetic building blocks called nucleotides, which are represented using the following codes: A, C, G, and T. A=Adenosine, C=Cytosine, G=Guanine, T=Thymine.
A triplet of three of these will make an amino acid. There are twenty different types of amino acids in the human body. Stringing together amino acids makes a protein. So, a string of AAA on your DNA will make the amino acid Lysine.
Here is the complete list of codes: DNA to protein coding
And this is a "map" of the circular pieces of mitochondrial (mtDNA). There are 16,569 base pairs in one mtDNA. It starts counting from 0 at the "D Loop". Here is a nice higher resolution map of Mitochondrial DNA.
Mitochondrial DNA "Cambridge Reference Sequence" Here is the "standard sequence" of 16,569 mtDNA patterns.