History of DNA
The search for our ancestors is a national pastime — the second most popular hobby after gardening. 1 After all, you're likely here because you want to learn more about your Sinclair genealogy.
We are all related—descended from a common African ancestor who lived only 60,000 years ago. 2 For some of us, this is difficult to believe. Certainly there were those alive 2.3 million years ago when the first homo sapien walked in Oduvai Gorge in Africa. Evidence suggests, however, that many of the descendants of these early humans died off or didn’t have children.
Most of our genetic material gets passed from one generation to the next through a process known as recombination. Recombination keeps us from being clones by giving everyone (except identical twins) a unique combination of genes, half from each parent.
That mixing process makes most of our DNA practically useless for inferring ancestry, at least with current technology. But there are two small sections of the genetic code that never recombine. The Y-chromosome, which confers maleness, is passed directly from fathers to their sons. Another odd little package of genes known as mitochondrial DNA (mtDNA) is always inherited from the mother. mtDNA mutates more slowly than YDNA, inherited from the father. This, plus the inheritance of surnames, makes YDNA more useful for most genealogy work in the last several centuries.
The tree of human evolution according to German evolutionary biologist Ernst Haeckel, 1891.
Today, thanks to DNA, we know a bit more about our origins.
Those two portions of DNA can only change by mutation. That means if you know how fast the genes of the Y-chromosome or mitochondrial DNA mutate over the generations, you can calculate how long ago two people shared a common ancestor by comparing their genetic code. 5
Speaking broadly, different population groups exhibit distinctly different markers. Following them through the generations reveals a genetic tree on which today's many diverse branches may be followed ever backward to their common African root. This is the study of Haplogroups, large branches on the human genetic tree.
Speaking more specifically, we’re looking for a specific branch near the top of the genetic tree, way out on only one Haplogroup branch. Looking within a given family and trying to understand the paths of specific branches of a family (Lineages) is much more difficult and requires more than the traditional DNA test to dissect these subtle nuances. This has been our quest, to find new ways to go beyond the DNA tests currently offered, as those tests are for people who want merely to solve a question of genealogy in the 1700s.
All genetic tests from Family Tree DNA will provide you a probability that you and another person, who have an exact match, will have your Most Recent Common Ancestor (MRCA) within a range of time backwards. The 12 marker test gives you the following range: 7 generations (50%) likelihood & 29 generations (95%) likelihood. We do not allow participation using only 12 markers as it’s generally useful for telling us who we’re related to about the time of the last ice age or 18,000 ago. Using the 25 marker test the 50% likelihood drops to 3 generations and the 95% to 13 generations. The 37-marker test tightens further to 2 generations (50%) and the 95% to 7 generations. (3 - FTDNA website) All this was made possible by Gregor Mendel, Frederick Griffith, Alec Jeffreys and others who followed them.
A Brief History of Genetics
Gregor Mendel the "Father of Genetics" kept records of every plant that was produced through his pea plant experiment. He started with 34 varieties of pea seeds in which he noticed 7 opposing characteristics among the plants. The pea plants were self-pollinating plants so Mendel was able to leave them alone after the first generation (0). With this generation he bred a tall plant with a short plant by manually cross pollinating them. In result, he noticed that all of the offspring were tall. The change came in the next generation, though, in which, out of the 1,064 plants obtained, 787 were tall and 277 were short. This was almost a 3:1 ratio of tall to short pea plants. On Sept. 10, 1984, at the University of Leicester, Alec Jeffreys stumbled upon DNA fingerprinting, identifying the patterns of genetic material that are unique to almost every individual.
Recent History of a Recent Science
The current testing methods for identifying humans and telling us apart have evolved from techniques which had quite a different purpose. Until the 1980s, the scientific community was concerned with matching blood and tissue donors with recipients, thus reducing the rejection rate for transplant patients. Such testing was, understandably, very expensive. The advent of PCR technology made mass production commercially viable and tests were created for the hobby genealogist. PCR is a technique through which samples of DNA fragments are replicated until billions of copies are made for accurate comparison. PCR is an abbreviation for "polymerase chain reaction." (POLL'-IM-ER-ACE). This term applies to a wide variety of different DNA tests that differ in reliability and effectiveness. Reliabilities of each kind of PCR test need independent verification. PCR itself doesn't accomplish DNA typing, it only increases the amount of DNA available for typing. 105 Because of the power of PCR, very small samples of DNA from any part of the body can be used in a DNA test.
1920s - Blood Typing
1930s - Serological Testing
1970s - HLA Testing
1980s - DNA Testing Using RFLP Technique
1990s - DNA Testing Using PCR Technology 104
Marketing Takes Over
DNA testing labs make money by testing folks who are interested in genealogy. The stakes are high. As of this writing, an estimated 460,000 people have taken genetic tests, from one of the many companies offering them, to determine their ancestry or to expand their known family trees, according to Science magazine. 9 That's about $57,500,000 spent on genetic testing for genealogy. Do you think the companies offering such comparisons are incentivized to tell you things you don't want to hear?
The phenomenal success of Family Tree DNA in taking over the lion’s share of testing means that other companies out there must find income by discovering new SNPs to test. One of the most successful of late has been EthnoAncestry. Their much publicized S21 marker is attracting many participants. Jim Wilson, the founder of EthnoAncestry sought me out for testing because he believed that S21 was proof of ‘The Earldom Lineage.’ Having tested a few Sinclairs of the Shetland Islands, he felt these Sinclairs had to be, for reasons of their geography, descended of this famous line of Sinclairs. This was his contention as it was felt that S21 was proof of Frisian descent. The Earl of Caithness was assumed to be of descent from the Merovingian blood line. The Shetlands being close to Orkney, it was assumed that they must be direct paternal descendants of the Earl. While I won’t wholly refute this (or many other ideas), I find it to be too simplistic a view as you’ll see in the section that discusses EthnoAncestry and S21.
A chromosome is a very long DNA molecule, with its associated proteins, which carries
portions of the hereditary information of an organism. The human haploid genome contains
3,000,000,000 DNA nucleotide pairs.
Marketing Is Important
I run a marketing company and I know the kind of attention one must generate to achieve success. Because most of the folks exploring DNA are not scientists or academics, some do not follow good scientific method. They also don’t have a tenured position at a university at stake and so leap to conclusions.
This urgency to leap to conclusions is, to me, one of the problems inherent in the hunt for these new SNPs. For instance, Hugh Montgomery, an author on European history (who, by his own admission ‘knows nothing about DNA’) has decided that CCR5-Delta-32 is what made certain of the population of Europe into ‘God Kings,’ a title he uses to describe the descendants of his ‘Davidic Lineage.’ 11
The reading I’ve done on CCR5-delta-32 makes it very clear that there is still debate as to how old the mutation is, and that determines how much value it is for our study. If, as one researcher has suggested, it’s 127,000 years old, then it’s of no value to us in a genealogical timeframe. But because so many have books to bring to market, the tendency is to state theories as fact before the science is old enough to be reliable.
Competition Is Good
At this writing; FTDNA has just launched a new way to dissect the R1b Haplogroup. This is not surprising as so many of their results must be in this Haplogroup. We’re talking big money here. For some of the participants in the Sinclair DNA project, this new dissection will prove useful but many of us are still falling within an undeterminable “DNA soup” of the Western European Germanic tribes.
EthnoAncestry has S21. Others will surely follow. The St. Clair DNA study is closely following all the different opportunities for our project out there. We’re not wed to FTDNA. They are the largest by far, but when we see another way to understand our family connections, we’ll definitely follow it.
As more time goes by, I believe the interest in genealogy will only grow. This will drive more money into the field and companies will be even more competitive with one another to offer better answers. The R1b conundrum will continue to be a problem that these companies will want to solve because it also matches up with the largest group of immigrants in the colonies, and these folks are the ones most interested in doing their genealogy to, in my opinion, find their way home again.
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