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mtDNA Maternal Haplogroup Origin

A Work In Progress by Herbert Holeman, PhD.

This draft workpaper was last modified .

Findings to date

• My mother-line roots originated in mainland Asia 43,000 years ago.

• My mother-line haplogroups are commonly found among today's populations in Southeast Asia as well as peopling the Americas.

• I have direct mother-line ancestral matches exist in the Philippines and Mexico.

Discussion

A ten-generation family tree has 1,024 ancestors yet an mtDNA mitochondrial test has the power to reveal information about just a single person out of those 1,024 ancestors. The mtDNA test permits me to pursue deeper into my genetic female line of ancestors.

The mitochondria received from mothers is passed down entirely unchanged, through the maternal line, unlike autosomal DNA (nuclear DNA), which mixes sections of maternal and paternal DNA resulting in a garbled genetic history.

Figure 11
Autosomal vs. Mitochondrial

Only mothers do. Only egg cells provide mitochondria to the following generation. Because of this independent origin, mitochondria have their own DNA. So, my mitochondrial full sequence analysis reveals only mother-line ancestry. It traces the entire mitochondria to form a unique ancestral tree.

The mtDNA depicted in Figure 11 follows only the direct line, it is matrilineal, meaning it traces only DNA inherited by my mother from my mother's mother, and so on ad infinitum. For example, my grandmother received DNA from her father and mother, but only the DNA my grandmother received from her mother is traced. This process is repeated back through the matrilineal line of her haplogroup.

To quote Genetic genealogist Roberta Estes "mtDNA can be very, very specific and yield definitive answers about individual ancestors, reaching far beyond the 5th or 6th generation." Moreover, mitochondrial DNA tests have been effective for tracing maternal lineage up to 52 generations ago according to an article by science writer, Ellen Hinkley. If I went back six generations in my own family tree, I would see my nuclear DNA is inherited from 32 men and 32 women. However, my mtDNA would come from only one of those 32 women.

Mitochondrial DNA usefulness for reconstructing prehistory reveals my mtDNA begins with the B4 branch of the haplogroup B tree. It is the origin of my mother line haplogroup and evolves with the passage of time to the present day through a series of genetic mutations. A mutation comes about about when a descendant has a genetic trait that her ancestor (mother) does not have. This new trait is known as a mutation. It derives a new branch of the mitochondrial haplogroup and can be linked to a period in time and a general geographic location.

My Mitochondrial full sequence analysis (MFSA) from Family Tree DNA is the highest level test of the mother-line mitochondria available. Table 8 presents my mother-line mutation discoveries to reflect matrilineal ancestral descent from Asia into the Americas.


The full timeframe in Table 8 is yet to be completed. But, thus far, the table confirms my mother-line begins with the B4 mutation and provides a date of 43,000 years ago in Asia. Thereafter Table 8 reports the next mutation to haplogroup B4b 34,000 years ago. Both of these dates happened in the Ice Age when lowered sea level allowed for crossing the Beringia landbridge connecting Asia to the Americas. Yet, not enough information exists to determine whether my archaic ancestor took advantage of the landbridge or stayed in Asia. The B4 and B4b1 haplogroups remain today as common among populations native to Southeast Asia and among speakers of the Austronesian family of languages. The Austronesian cluster includes the present day populations from Southeast China, Myanmar (Burma), Vietnam, Cambodia, and Laos on the mainland to the islands of Taiwan, the Philippines, Brunei, Sumatra, and the Malaysian Peninsula.

As for my subsequent mutation to haplogroup B4b1, Table 8 gives no geographical location for it. However, Maternal haplogroup B4b1 is found today mainly in populations of southern China and Southeast Asia, especially among Filipinos and the indigenous people of Taiwan. Genetic affinities between indigenous Taiwanese and populations from Southeast Asia have been explored through analyses of mitochondrial DNA (mtDNA).

Yet, at some point, a subsequent mother-line ancestor's clan migrated into the Americas. Current thinking puts it during the the Ice Age by way of the via the 1,000 miles wide Beringia Land Bridge (Figure 12).

Figure 12
Haplogroup B2c1 Migration

At the time it bridged the two continents, but a study by evolutionary geneticist Eske Willerslev and David Meltzer, an archaeologist, reveals it was largely impassable until 12,600 years ago when vegetation and animal life emerged. Yet, shortly thereafter, Beringia sank under the sea ~11,000 years ago.

What's more, the Americas had already been long been peopled by Asian populations before that time. Human habitation in Mexico existed ~33,000 years ago. Study coauthor, Mikkel Pedersen, suggests earlier migrations into the Americas by way of a yet to be discovered route along the Pacific coast.

Figure 13
Haplogroup B Migration
Alternative Routes

Whatever the route to the Americas, my early B2 ancestor is one of the founding mother-lines of the indigenous peoples of the Americas. She gave rise to my B2c descendent who ultimately reached the southern tropical lowlands of Mexico where my B2c1 mother was born in the coastal gulf state of Tabasco. Interestingly, the Olec's represent the earliest known civilization Mexico, which existed around 2600 years ago in the Tabasco tropical lowlands. Figure 16 depicts this extension of the backbone of Haplogroup B from Asia to the Americas.

As suggested in Mikkel Winther Pederse map (Figure 13) migration into the Americas likely could have been near to the date of the B2c mutation 16,000 years ago or just as likely began some time as late as ~10,000 years ago or even more recently. Additionally, the haplogroup pattern in Table 8 is shared in part by other testers in the FamilyTree,com DNA database as evidenced in Figure 11. Along with other testers in haplogroups B4'5 and B2c1, it reports I share the Philippines as a maternal country of origin. To paraphrase Elise Friedman in her webinar discussion of the mtDNA haplogroup Origins depicted in Figure 11, she explains if I match someone genealogically it means that we share a common ancestor on my direct maternal line somewhere in time. I cannot have a haplogroup that is different than someone whom I match genealogically.

Moreover, the genetic distances shown confirm we are indeed a match. The less the genetic distance, the closer we are related. Genetic distance as an indicator of genetic relationship is measured in units of centimorgans.

Figure 14
Test-Takers Haplogroup Origin

Family Tree DNA Mitochondrial Full Sequence Analysis


According to the chart in Figure 14: "The following information about your mtDNA matches is displayed:

Haplogroup - This is your matches' haplogroup as determined by their Backbone SNP testing or their mtDNA full sequence test results. [See Table 8]
Country - This is your matches' maternal country of origin."

The chart in Figure 14 reports I have two matches with other DNA testers in the HVR1 MATCHES section of the chart. Matching on HVR1 means that we have a 50% chance of sharing a common maternal ancestor within the last fifty-two generations. That is about 1,300 years. These two testers identify with the Philippines.

The countries, Mexico and the Philippines, are shown to have present day testers in the mtDNA haplogroup B2c1. They appear in the website chart of FamilyTree.com of the countries of origin for each branch of the mtDNA Haplotree. The chart is based on the world's largest mtDNA database. It contains 170,000 mtFull Sequences from over 180 different countries.

As to Mexico, the specific destination reached by my maternal ancestors migration into the Americas, the mitochondrial full sequence analysis concurs with the consensus of autosomal companies. To that point, the geographic coordinates in Figure 15 are the WeGene test company's reference population that pinpoint my maternal lineage in the Americas.

Figure 15
Wegene Maternal Reference Populations

The geographic map coordinates in Figure 16 is consistent with my mother’s birthplace and family location, which is evidenced in documentation, such as birth certificates, census reports, etc. Publications exists of generations of my mother's ancestors living in thos geographical area since the 1700s.

Figure 16
Wegene Maternal Map Reference
Ancestry

A good video on the mtDNA Full Sequence panel from FTDNA by Elise Friedman.

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