Scientists have compiled the world’s largest family tree, an endeavor that reveals new insights into both European and North American history.
Researchers from Columbia University used Geni.com to create the tree, which encompasses roughly 13 million people. After downloading over 80 million public profiles, researchers used mathematical analysis to organize the data. That allowed them to create an interconnected family tree that spans out over 11 generations.
“Family trees have vast applications in multiple fields from genetics to anthropology and economics,” the authors wrote in the study, according to Newsweek. “However, the collection of extended family trees is tedious and usually relies on resources with limited geographical scope and complex data usage restrictions.”
Nearly 85 percent of people looked at in the study came from either Europe or North America. As a result, the tree allowed the team to get a look into how both continents are connected. While they learned a range of interesting things, one of the most useful was the shifting patterns of marriage and migration over time.
For instance, before 1850, many people married within the family. Though researchers previously believed people in the West stopped marrying relatives as a result of improved transport networks, the new data revealed that between 1800 and 1850 people were more likely to marry a fourth cousin. As a result, the team believes the practice died out because it became less socially acceptable over time.
Another surprising discovery is that women in both North America and Europe migrated more than men over the last 300 years. However, when men did migrate they traveled greater distances on average.
This new data is important because it could help answer a wide range of genealogical and scientific questions.
“We hope people use it,” said Yaniv Erlich, a data scientist and computational biologist at the New York Genome Center, according to National Geographic. “You can look at local disasters, individual families, anthropological questions, fertility rates—the data could be used for all of those things.”
A new study published in the journal Science reports.