Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy

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Open access Close inbreeding and low genetic diversity in Inner Asian human populations despite geographical exogamy, by Marchi et al. Scientific Reports (2018) 8:9397.

Abstract (emphasis mine):

When closely related individuals mate, they produce inbred offspring, which often have lower fitness than outbred ones. Geographical exogamy, by favouring matings between distant individuals, is thought to be an inbreeding avoidance mechanism; however, no data has clearly tested this prediction. Here, we took advantage of the diversity of matrimonial systems in humans to explore the impact of geographical exogamy on genetic diversity and inbreeding. We collected ethno-demographic data for 1,344 individuals

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Quantitative analysis of population-scale family trees with millions of relatives

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The paper Quantitative analysis of population-scale family trees with millions of relatives, by Kaplanis, Gordon, Shor, et al. Science (2018) 359(6379), based on a study of genealogical information at Geni, is today news worldwide.

Abstract:

Family trees have vast applications in multiple fields from genetics to anthropology and economics. However, the collection of extended family trees is tedious and usually relies on resources with limited geographical scope and complex data usage restrictions. Here, we collected 86 million profiles from publicly-available online data shared by genealogy enthusiasts. After extensive cleaning and validation, we obtained population-scale family trees, including

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We are all special, which also means that none of us is

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Adam Rutherford writes You’re Descended from Royalty and So Is Everybody Else – Anybody you can name from ancient history is in your family tree, which I discovered via John Hawks’ new post The surprising connectedness of human genealogies over centuries.

Excerpt:

One way to think of it is to accept that everyone of European descent should have billions of ancestors at a time in the 10th century, but there weren’t billions of people around then, so try to cram them into the number of people that actually were. The math that falls out of that apparent impasse

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