Responses

1. 

   Anthony G. Baxter

   July 26, 2026

   I saw this question on Quora: “My father is white, my mother is black. What am I?”

   Do you care to comment?

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2. 

   Anthony G. Baxter

   July 26, 2026

   Anthony’s Response:

   Because “black” and “white” are arbitrary sociopolitical constructions, such categories have no genetic basis. As such, these constructions do not convey genetic information. Asking, “If my mother is black and my father is white, what am I?” Is like asking “If my mother is a Democrat and my father is a Republican, what am I?” A “Republicrat,” a “Democan,” utterly ridiculous right?!

   The more productive-illustrative question to ask is this: “If one of my grandparents has ancestral roots in West Africa; one in North Africa; one in Europe; and one in America, what am I?” When you take your DNA test, it will breakdown your basic DNA admixture as follows: 25% West African; 25% North Africa; 25% European; and 25% Native American.

   Although the above example is crude, it nevertheless is accurate. On websites like Ancestry or 23andMe, their admixture comparison algorhythms would provide a finer breakdown, e.g., the 25% European portion might be presented as 12.5% Irish and 6.25% Scottish, and 6.25 Wales, while the 25% North African might be presented as 6.25% Moroccan, 6.25 Algerian, and 12.5% Tunisian.

   The main point is that admixture captures the diversity in the DNA we inherit from our forebears. The notion that people from diverse ancestral areas are mixed is a mistake that is based on a faulty assumption called “Blood Quantum” that gave rise to such racists notions as “the one-drop rule,” dictating that one drop of black blood (1/32) means you are black.

   Finally, admixture connotes that the admixed portions result is a stronger substance, whereas mixture connotes a dilution of substances.

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3. 

   Anthony G. Baxter

   August 15, 2026

   Question: A young girl, born around 1810, living in the Senegambia region of West Africa, probably Guinea or Guinea-Bissau as she is a member of the Mandinka (Mandingo) tribe, is taken captive around 1823, shipped to the Americas, and sold into life-long servitude. What admixture patterns would her living descendants most likely show upon autosomal DNA testing? What MT-DNA haplogroup would her direct maternal line descendants likely show?

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   1. 

      Anthony G. Baxter

      August 15, 2026

      The Google Gemini response to this question is as follows:

      The living descendants of this Mandinka girl would exhibit highly predictable autosomal and mitochondrial DNA (mtDNA) profiles, shaped by the historical mixing of the Transatlantic Slave Trade and the precision of maternal genetic inheritance.Autosomal DNA Admixture Patterns

      Autosomal DNA is inherited from all ancestors and reshuffled every generation. Because this ancestor represents only one branch of a family tree from roughly 7 to 8 generations ago (contributing less than 1% of the descendants’ total DNA), the overall autosomal profile of her living descendants will depend heavily on the history of the population they married into. [1, 2, 3, 4]

      Assuming her descendants live within the broader African American or Afro-Diasporic communities in the Americas (e.g., the United States, Brazil, or the Caribbean), their autosomal testing would likely reveal the following continental and regional breakdown: [5, 6]

      • Continental Admixture: In the United States, the average African American autosomal profile typically shows roughly 75% to 80% Sub-Saharan African ancestry, 15% to 24% European ancestry (primarily British/Irish), and 1% to 2% Native American ancestry. [1, 7, 8]
      • West African Sub-Regional Breakdown: Within their Sub-Saharan African component, modern commercial tests (such as 23andMe or AncestryDNA) would explicitly flag a strong signature from the “Senegambia” or “Senegambian & Guinean” region. [9, 10]
      • Interethnic African Mixing: Even though this specific ancestor was Mandinka, she would have mixed with enslaved Africans from other regions over the generations. Therefore, the modern descendants will also show high autosomal percentages from “Nigerian” (Yoruba/Igbo) and “Coastal West Africa” (Ghana/Liberia), as well as “Congo/Western Bantu” regions, reflecting the overall demographics of the transatlantic slave trade. [1, 5, 11]

      Mitochondrial DNA (mtDNA) Haplogroup

      Unlike autosomal DNA, mitochondrial DNA is passed down completely unchanged from mother to child along the direct maternal line (mother’s mother’s mother). If the living descendant traces back to this young girl through an unbroken line of women, their mtDNA haplogroup will perfectly match hers, remaining entirely unaffected by any European or other African intermixing in the family tree. [2, 4]

      As a member of the Mandinka tribe in the Guinea/Guinea-Bissau region, her direct maternal line descendants would carry a branch of the L Haplogroup (the foundational African maternal lineage), with a very high probability of belonging to one of three specific subclades: [12, 13, 14, 15]

      1. Haplogroup L2 (specifically L2a1 or L2c): This is the most probable result. L2 is highly prevalent across West Africa. Genetic surveys of Guinea-Bissau show that L2a1 makes up about 15% of the local population, while L2c makes up roughly 9% and is incredibly specific to the Senegambian coastal fringe. [16, 17, 18, 19]
      2. Haplogroup L3 (specifically L3d or L3e4): L3d (found at ~13% in Guinea-Bissau) and L3e (found at ~9%) are heavily associated with the Mandinka and neighboring Upper Guinea groups. [16]
      3. Haplogroup L1b: Representing about 6% of the region’s lineages, L1b is an ancient West African-specific haplogroup that frequently appears in the direct maternal lines of modern African Americans. [16]
      4. Haplogroup L2e: Though rarer, L2e is a fascinating lineage that geneticists consider an explicitly diagnostic marker for the Mandinka people of Guinea-Bissau, and it is well-documented among African American descendants. [17]

      Summary: While the descendant’s autosomal DNA will look like a diverse mosaic of the African Diaspora (heavily weighted toward general West and Central African regions), their mtDNA will pinpoint an ancient, unbroken maternal signature—most likely L2a1, L2c, L3d, or L2e—directly linking them back to the Upper Guinea coast. [16, 17, 20]

      [1] https://pmc.ncbi.nlm.nih.gov

      [2] https://guides.loc.gov

      [3] https://www.youtube.com

      [4] https://www.facebook.com

      [5] https://en.wikipedia.org

      [6] https://www.facebook.com

      [7] https://pmc.ncbi.nlm.nih.gov

      [8] https://www.youtube.com

      [9] https://www.academia.edu

      [10] https://onlinelibrary.wiley.com

      [11] https://elifesciences.org

      [12] https://digituma.uma.pt

      [13] https://www.afrigenetrylink.org

      [14] https://www.familytreedna.com

      [15] https://blog.familytreedna.com

      [16] https://pubmed.ncbi.nlm.nih.gov

      [17] https://blog.familytreedna.com

      [18] https://www.academia.edu

      [19] https://www.genesispub.org

      [20] https://www.facebook.com

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4. 

   Anthony G. Baxter

   August 15, 2026

   Question (August 15, 2026)

   This slave woman. by her own account a “Guinea Woman,” would pass one of her X chromosomes to her male and female children, so her sons’ children, her granddaughters would carry her MT-DNA because the Male has only his mother’s X chromosome to pass. The slave woman’s seven granddaughters, her son’s children, would have two X chromosomes to pass, one from her father and one from their mother. One of the seven granddaughters marries and has seven daughters. What is the probability that the granddaughter passed her grandmother’s X to one or more of her seven daughters?

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5. 

   Anthony G. Baxter

   August 15, 2026

   Return (Aug 15, 2026):

   When tracking that X chromosome further down the family tree, the transmission ceases to be a simple 50/50 “all-or-nothing” coin flip. This is due to a biological process known as genetic recombination (or “crossing over”).

   The way recombination reshapes, fragments, or preserves your West African ancestor’s X chromosome across generations behaves quite uniquely compared to autosomal chromosomes.1. The Recombination Rule for X Chromosomes

   Recombination occurs when a parent’s cell creates an egg or sperm. The parent’s two matching chromosomes line up, swap segments, and create a brand-new, unique mosaic to pass down. However, this only happens under specific conditions for the X chromosome:

   • In Males (No Recombination): A biological male has an X and a Y chromosome. Because they do not match, they cannot recombine. A father passes his single X chromosome to his daughters completely intact, exactly as he received it from his mother.
   • In Females (Active Recombination): A biological female has two X chromosomes. When she creates an egg, those two X chromosomes cross over. The child receives a blended X chromosome—a mix of maternal grandmother and maternal grandfather DNA.

   2. Tracing the Generations: Step-by-Step

   Let’s trace how the “Guinea Woman’s” X chromosome behaves in your specific lineage as it moves forward from the great-granddaughters (the 7 daughters of the granddaughter).[Generation 1] Guinea Woman (Two X chromosomes) │ ▼ Passes intact X (50% chance of either) [Generation 2] Son (One intact X from mother) │ ▼ Passes 100% intact X to ALL daughters [Generation 3] 7 Granddaughters (One intact X from father, one from mother) │ ▼ RECOMBINATION HAPPENS HERE (Mother's two Xs swap pieces) [Generation 4] 7 Great-Granddaughters (Each receives a mosaic X chromosome) At Generation 4 (The 7 Great-Granddaughters)

   The granddaughter has two X chromosomes: one from her father (the 100% intact Guinea Woman X) and one from her mother.

   When she passes an X chromosome to her daughters, her two Xs recombine. The human X chromosome is roughly 180 centimorgans (cM) long. Because it is physically long, it undergoes an average of 1 to 2 crossover events every time an egg is formed.

   • The Broken Block: Instead of getting the whole West African X chromosome, each great-granddaughter will inherit fragmented “blocks” of it. One daughter might get the top 60% of the chromosome, another might get a 30% chunk in the middle, and another might get two smaller pieces totaling 50%.
   • The Intact Exception: Statistically, there is a 16.5% chance that an egg is formed with zero crossovers. This means there is a small chance that one of those 7 great-granddaughters actually did inherit the original West African X chromosome completely intact, without a single break.

   3. The Multi-Generational Outlook

   As the generations march on from 1823 toward the present day (roughly 7 to 8 generations later), two fascinating divergent paths emerge depending on the gender of the ancestors in the chain:The “All-Female” Chain (Rapid Fragmentation)

   If the lineage moves exclusively from mother to daughter to daughter:

   • Recombination happens in every single generation.
   • The original West African segments get chopped smaller and smaller.
   • By the 8th generation, a living descendant might only carry a few tiny fragments (e.g., 5 to 15 cM blocks) of the original X chromosome, or the segments may have dropped off entirely due to random chance.

   The “Father-Daughter” Brake (The Preservation Strategy)

   Because men do not recombine their X chromosome, every time a male appears in the lineage, recombination stops.

   • If a woman passes a fragmented X chromosome to her son, that exact fragment is safely locked in place.
   • When that son has daughters, he passes that fragment down 100% intact and unchanged.
   • Lineages with alternating generations of mothers and fathers will preserve much larger, more cohesive blocks of the original West African X chromosome than lineages of all-female lines.

   4. What this looks like on a Modern DNA Test

   If a living descendant uploads their raw data to a platform like GEDmatch (which features a dedicated X-DNA browser), they can look specifically at their X chromosome.

   If they match a distant cousin on the X chromosome along this specific lineage, they will see a distinct block highlighted. Because the girl was Mandinka, looking at the specific genetic markers inside that X-DNA block would map directly back to reference populations in Senegambia and Guinea.

   Would you like to explore how Y-DNA behaves in a parallel fashion for the paternal side of a family tree, or calculate the odds of a specific fragment surviving to a 21st-century descendant?# Let's calculate the exact probability of an X chromosome remaining entirely intact over generations, # or how recombination reduces the size of the original segments. # The genetic length of the human X chromosome is roughly 180 Centimorgans (cM). # Number of recombinations per meiosis in females for the X chromosome is roughly 1 to 2. # Let's verify the probability of 0 crossovers on a chromosome of length L = 1.8 Morgans. import math L = 1.8 prob_no_crossover = math.exp(-L) print(f"Prob of absolute intactness (no crossovers): {prob_no_crossover:.4f}")

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6. antgbax-mglex

   August 17, 2026

   […] Curious about DNA Science and DNA Genealogy? Ask Anthony and His Community of Subscribers Your … […]

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7. 

   Carolyn

   August 18, 2026

   What are the specific genetic markers that great great grandmother Leah Ruth Warner passed to her descendents?

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   1. 

      Anthony G. Baxter

      August 18, 2026

      Great-Great grandmother Leah Ruth Warner was a member of the Gullah-Geechee Mitchelville community on Hilton Head Island in the South Carolina Lowcountry. She self-identified as a “Guinea Woman” where the predominant tribe is the Mandinka (Mandingo) people. The Gullah-Geechee people have a Genetic Signature on AncestryDNA.

      Unlike typical African American profiles that often show a wide, highly mixed, multi-regional West/Central African distribution due to post-emancipation internal migrations, Gullah-Geechee descendants exhibit a distinct “Rice Coast Cluster.”

      Because the Lowcountry rice plantations actively sought out captive laborers from specific rice-growing zones in West Africa (e.g., Senegambia, Guinea, and Sierra Leone) for their specialized agricultural expertise, and because these isolated sea island communities married predominantly within their own regional/cultural groups, they retained an unusually high and intact percentage of African DNA (often testing at 80% to 95%+ Sub-Saharan African heritage).

      When looking at your AncestryDNA results to find the echo of your Mandinka great-great-grandmother, look for these specific geographic indicators:

      1) Senegal and Mali Categories: On AncestryDNA, genetic markers from the historical Senegambian coast and Mandinka homelands frequently map significantly to the Senegal and Mali reference regions. The Mali category in particular captures a massive portion of the broader Mande-speaking genetic pool that includes the Mandinka.

      2) Ivory Coast & Ghana / Sierra Leone / Benin & Togo: Because the trade brought a deliberate fusion of neighboring coastal groups alongside Senegambians to the Carolinas, a Gullah-Geechee profile typically presents a concentrated West African blend rather than a single isolated 100% match to one modern country.

      3) The “Early South Carolina African Americans” Genetic Community: Check your Communities tab on AncestryDNA. If you have deep Lowcountry roots, Ancestry often assigns a specific Genetic Community (such as Early South Carolina & Georgia African Americans) which statistically confirms the regional continuity of your lineage.

      Look at your DNA admixture on Ancestry for these markers to see great-great grandmom Leah’s legacy, what she passed on to her generations.

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      1. 

         Anthony G. Baxter

         August 29, 2026

         If we could trace the unbroken female line from GGM Leah to her living descendants, we would be able to confirm her descent from the Senegambia Region which includes Guinea, Mali, Gambia, Senegal, Guinea-Bissau. This is the region that her Mandinka (Mandingo) tribe occupies.

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8. 

   Anthony G. Baxter

   August 29, 2026

   Who is mitochondrial Eve, who scientists call the Mother of all humanity?

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   1. 

      Anthony G. Baxter

      August 29, 2026

      Watch this video from Penciled in History to learn who was Mitochondrial Eve, the most consequential woman who ever lived, then share what you learned with our Learning Community that you did not know before you watched the video.

      Mitochondrial Eve: Penciled in History

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