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To borrow a phrase, to know who you are, you have to know where your story began. DNA makes this possible. It is a substance, a chemical called deoxyribonucleic acid, and as science writer, Sam Kean says, for more than three billion years, DNA has been copying human history. Oxford researcher, Dr. Simon Myers, adds, "DNA really has the power to tell stories and uncover details of humanity's deep past using only genetic data, independent from other sources.
Thus, Ancient DNA fills in the human past with data rather than inference. This is the perspective I follow to tell the story of the world trail traveled through the ages by my deep genetic ancestors. I do this by using biogeographical based DNA in the form of haplogroups.
A haplogroup is defined by the International Society of Genetic Genealogy (ISOGG) as "a genetic population group of people who share an ancestor in common on either their paternal or maternal line."
So, each person possesses two haplogroups, one from each of their birth parents. Each of these haplogroups follow gender descendancy lines. One haplogroup follows the Y-DNA passing from father to son. The other haplogroup follows the mtDNA, which passes from mother to both daughters and sons.
Each of my haplogroups trace my ancestral genetic lines. Each weaves a pattern of geographical migrations that contribute to changes in my genome in the form of ancestral admixture. Admixture is the result of people interbreeding, such as when a group of people from one geographic location migrate into a new location inhabited by people of another group.
As both groups have children together, their children's DNA becomes a mixture of the DNA from each admixing group. When subsequent generations repeat this process, the genomes of descendants contain pieces of DNA inherited from each admixing. Haplogroups are formed from sorting these remaining bits of DNA admixture and organizing them. This process reveals where our ancestors came from because each haplogroup has related patterns of DNA sequences (haplotypes) that represent that population.
The haplogroup process can be likened to that experienced by such ancestral groups as the Vikings, Celts, and Mongols. Interestingly, a haplogroup reappraisal of the Viking image revealed many of whom were in actuality farmers with families seeking to migrate for a better life.
That study tells a story of a genetic legacy of modern diversity from paternal Y-DNA and maternal mtDNA in a population's gene pool. It reveals population admixture from male subjects whose patrilineal ancestry lay in Scandinavia and female subjects whose matrilineal descent lay within the British Isles.
The power of DNA becomes clear in a study's findings reported in 2020. The remains of several people buried as Vikings in Norway were found to be actually closer genetically to East Asians than to Europeans. Similar, findings occured in another study which examined the genetic imprints of the Mongolian clans on global ethnic admixture.
In revealing patterns of human migration, the Human Genome Project reached out to indigenous populations who kept the link to the geography of their ancient historical past and concluded: "Your haplogroup is your branch on the human family tree. All people alive today belong to distinct haplogroups ... People belonging to the same haplogroup can trace their descent to a common ancestor and even a specific place where that ancestor may have lived."
That said, haplogroups serve a variety of purposes, such as scientists correlating haplogroups with a broad spectrum of common diseases.
However, my focus with haplogroups is with tracing the biogeographical line of my genetic ancestors and learning something of their world's milieu.