When Did Americans Stop Marrying Their Cousins? Ask the World’s Largest Family Tree
With crowdsourced genealogy, “we have the ability to connect a much more vast network of individuals
and locations around the world, in a faster, cheaper way,” said Dr. Erlich, who is also a computer science professor at Columbia University.
“It’s very impressive as a data collection and harmonization effort,
and of course they have only scratched the surface of what it might have to offer,” said Philip Cohen, a sociology professor at the University of Maryland, who was not involved in the research.
The largest tree consisted of 13 million people, spanned an average of 11 generations
and included both Sewall Wright, a founder of human population genetics, and the actor Kevin Bacon (the two are separated by 24 degrees, in case you were wondering).
Dr. Erlich and his collaborators took steps to validate the company’s trees, then reported several new findings from the data, such as a lower heritability of life span than others have reported,
and a greater likelihood of mothers to migrate than fathers.
