Run your tongue along the back of your two front teeth. Most people feel a smooth wall. Some of you will feel a ridge up each side and a scoop in the middle — a “shovel-shaped” incisor. That scoop is one of the clearest genetic signatures a human body can carry: near-universal in East Asian and Native American populations, nearly absent in Europe and Africa. And it was never really about teeth.
https://youtu.be/PfiLXX3cLxY
This is the documented story of that mark: the 1920 Smithsonian paper that made shovel teeth a marker of human migration, the 2009 study that pinned the trait to a single gene variant — EDAR V370A, catalogue number rs3827760 — the 2013 experiment that built that human variant into living mice and watched it change hair, sweat glands and the milk ducts of the breast, and the 2018 argument that the real driver of one of the strongest selection sweeps in the human genome may have been mothers nursing infants on Beringia — the drowned ice-age plain between Siberia and Alaska. At the end: how to look this exact variant up in your own DNA raw data tonight.
This is the honest version: the gene is proven, the mouse results are proven, the frequencies are proven — and where the “why” is still an open scientific debate, we say so out loud instead of pretending it’s settled.
⏱ CHAPTERS
0:00 Cold Open — Run Your Tongue Across Your Teeth
1:42 Chapter 1: The Man Who Read Teeth Like Maps
4:06 Chapter 2: The Chewing Theory — and the Hole in It
5:43 Chapter 3: The Gene That Was Never About Teeth
8:10 Chapter 4: The Mice That Carried a Human Mark
10:18 Chapter 5: The Land That Drowned
13:28 Chapter 6: The Mark You Can Check Tonight
15:23 Closing — The Receipt
📚 SOURCES & RESEARCH:
1. Kimura et al. (2009) — A Common Variation in EDAR Is a Genetic Determinant of Shovel-Shaped Incisors
https://pmc.ncbi.nlm.nih.gov/articles/PMC2756549/
2. Kamberov et al. (2013) — Modeling Recent Human Evolution in Mice by Expression of a Selected EDAR Variant
https://pubmed.ncbi.nlm.nih.gov/23415220/
3. Hlusko et al. (2018) — Environmental Selection During the Last Ice Age on the Mother-to-Infant Transmission of Vitamin D and Fatty Acids Through Breast Milk
https://pmc.ncbi.nlm.nih.gov/articles/PMC5948952/
4. Hrdlička (1920) — Shovel-Shaped Teeth
https://onlinelibrary.wiley.com/doi/10.1002/ajpa.1330030403
5. Tamm et al. (2007) — Beringian Standstill and Spread of Native American Founders
https://doi.org/10.1371/journal.pone.0000829
6. Smithsonian — Hrdlička, Shovel-Shaped Teeth
https://research.si.edu/publication-details/?id=120113
#ShovelTeeth #DNA #HiddenAncestry #NativeAmericanAncestry #EDAR #Beringia #IceAge #Genetics #HumanEvolution #StoneAndBone BS205AR
A tooth trait or a single genetic marker is a population-level signal, never proof of any individual’s ancestry — the video states this limit explicitly, in both directions. Where the science is still debated (why the variant spread), the video presents the competing hypotheses rather than picking a winner. Some scenes are dramatized reconstructions of the deep past. Nothing here is medical or ancestry advice.
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