GENETIC GENEALOGY PRATICUM
By Duke B. Montgomery, APG, NGS, AAHGS, CBPG Candidate
A few weeks back at the Rootstech 2017 conference I met with two Physicists and one Biochemist who work in the field of Genetics genealogy. It was not a planned encounter, we just happened to be in the same place at the same time. They asked to see my web blog site and I shared with them my goals and objectives with the site. The conversation led to an hour discussion Thursday morning to conversations late Thursday afternoon. This was not planned at all. The results have led to agreements to share their information on my web blog site. This is very exciting to me as the site information grows extensively.
I am really proud to connect with GPS Origins, a new DNA testing site providing a revolutionary ancestry DNA test that takes you deep into your family history. Traditionally, DNA ancestry tests provided a report of your ‘ethnicity’ and located parts of your DNA in broad continental sweeps, but nothing specific, not even to the country level. The GPS Origins (Geographic Population Structure) ancestry test combines the latest genetic research with new ancestral tracking techniques to pinpoint more precisely where your DNA began. The GPS Origins indicates the town or village where groups of your ancestors from different cultures met-building a vibrant picture of the migration journeys that formed your deep genealogical heritage.
I believe we improve our knowledge and understanding of DNA by the generosity and contributions of others. We learn from discussion with colleagues at genetic genealogy and genealogy conferences and institutes. I offer my gratitude to all my family members who swabbed their cheeks or spit into a tube. Without their contribution on 23andMe, Ancestry, Gedmatch and FTDNA, I would not be able to use their raw data to compare matches and make determinations using genetic standards.
I would not have been able to make the connections in the two strong branches of my tree, evidencing European ancestry to Wales, Scotland and UK and my African ancestry in present day Ghana and Nigerian. My ancestors were Igbo and considered the original Jews of God. There was more than one Adam and Eve within the same time period of life of mankind. They are called the genetic Adam and Eve.
Genetic genealogy is the application of DNA evidence to genealogical research. There are two standards that must be met, Genetic Genealogy standards and the Genealogy standards. Both provide a unique way of validation and verification. Genetic genealogy encompasses tables, charts, numbers and diagrams, whereas Genealogy encompasses sources, citations, historical records; two very distinct and separate methods.
Genetic genealogy-DNA testing has moved to a new level of learning about one’s heritage and provides a key for unlocking some secrets that the paper trail can never reveal. Sometime soon, there will be an announced merger of genetics and genealogy – genetealogy (ge-neh-tee-ol-o-gee). That will make it possible to find our twelfth and sixteenth cousins.
In this blog I introduce the type of DNA or a DNA-testing concept that is fundamental to understanding and use of genetic genealogy. I suggest that readers should master each section before moving on.
Genetic genealogy is a complex subject. It is a challenge to grasp all of the intricate details. I have read the position papers, articles and blogs from labs, DNA testing companies and scientists and have made the information readable to the public. It is an exchange that goes back and forth several times to make sure what is offered on the blog is accurate.
Education will never be complete. Tests and tools are constantly being developed and changed. Newly discovered methodologies are being shared in forums, special interest groups and international scientific groups in the UK, France and Israel, and in Germany particularly.
Understanding clearly the types of DNA humans inherit can help genealogists research and confirm with confidence different portions of a family tree. DNA types are:
- autosomal DNA (atDNA), which is composed of chromosomes 1-22 found in the cell nucleus; and
- mitochondrial DNA (mtDNA), found outside of the cell nucleus in tiny organelles called mitochondria (mitochondrion being the singular form);
- The sex-determining chromosomes, Y-DNA and X-DNA, also found in the cell nucleus.
The twenty-two autosomes and the X and Y chromosomes collectively are called nuclear DNA, as they are contained within the nucleus.
At this point let’s be clear up-front that these blogs on this website is about genetics for genealogists not vice versa. No matter if you are a beginner, intermediate or advanced genealogist there are plenty of learning opportunities presented. First of all, the term “DNA Testing” is a somewhat vague or imprecise way of labeling this process. I offer DNA Charting or DNA typing as an alternative. The science of genetic genealogy is changing constantly every day. However you refer to it, though, it is simply the process of determining whether two individuals share a common ancestor by comparing an infinitesimal fragment of their respective DNA. It is a warm feeling of excitement that fields like Anthology, Archaeology, Sociology and Genealogy how found new roots.
What secrets does our DNA offer? We learn our species is young, that we are ultimately all African, and that we are all cousins. (Scientists have determined that all of mankind originated in Africa, and some of us hung around Africa longer than others!) In fact we are so closely related that 99.9% percent of our DNA is identical. Yet the remaining 1/10 of a percent, that one part in a thousand, translates into about 3 million differences between any two of us (with the exception of twins, of course). We are all alike, yet are unique. Most of the variations are found in “junk” DNA – sections of DNA that serve no purpose, yet preserve our ancient history because they (DNA) are copied more or less faithfully for generation after generation.
If we could track a little snippet of DNA that shows one of these variations, we’d follow a path that meandered back through generations: It came from one of our two parents, one of our four grandparents, one of our eight great-grandparents. The numbers double with each generation: 16, then 32, 64, 128, 256. By the time you reach 10 generations, that little snippet of DNA could come from any one of 1,024 potential ancestors.
The next series of blogs will provide an explanation of the different types of tests, their usage in genealogy research, and how to read test results, matches and coding.