When Did Americans Stop Marrying Their Cousins? Ask the World’s Largest Family Tree<br />With crowdsourced genealogy, “we have the ability to connect a much more vast network of individuals<br />and locations around the world, in a faster, cheaper way,” said Dr. Erlich, who is also a computer science professor at Columbia University.<br />“It’s very impressive as a data collection and harmonization effort,<br />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.<br />The largest tree consisted of 13 million people, spanned an average of 11 generations<br />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).<br />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,<br />and a greater likelihood of mothers to migrate than fathers.
