Curiously, the researchers found that between 18, people traveled farther than ever to find a mate - nearly 12 miles (19 kilometers) on average -but were more likely to marry a fourth cousin or closer. "It became harder to find the love of your life," Erlich jokes.īefore 1850, marrying in the family was common - to someone who was, on average, a fourth cousin, compared to seventh cousins today, the researchers found. Before 1750, most Americans found a spouse within six miles (10 kilometers) of where they were born, but for those born in 1950, that distance had stretched to about 60 miles (100 kilometers), the researchers found. Industrialization profoundly altered work and family life, and these trends coincide with shifting marriage choices in the data. "This fact is known from basic population history principles, but what the authors have achieved is still very impressive." "The reconstructed pedigrees show that we are all related to each other," said Peter Visscher, a quantitative geneticist at University of Queensland who was not involved in the study. population's education level by cross-checking a subset of Vermont profiles against the state's detailed death registry. The researchers verified that the dataset was representative of the general U.S.
The dataset details when and where each individual was born and died, and mirrors the demographics of individuals, with 85 percent of profiles originating from Europe and North America. "It's an exciting moment for citizen science," said Melinda Mills, a demographer at University of Oxford who was not involved in the study "It demonstrates how millions of regular people in the form of genealogy enthusiasts can make a difference to science. The researchers also make it easy to overlay other datasets to study a range of socioeconomic trends at scale. Still, the dataset represents a milestone by moving family-history searches from newspaper obituaries and church archives into the digital era, making population-level investigations possible. Theoretically, they'd need to go back another 65 generations to converge on one common ancestor and complete the tree. What emerged among other smaller family trees was a single tree of 13 million people spanning an average of 11 generations.
The researchers downloaded 86 million public profiles from, one of the world's largest collaborative genealogy websites, and used mathematical graph theory to clean and organize the data. "We hope that this dataset can be useful to scientists researching a range of other topics." "Through the hard work of many genealogists curious about their family history, we crowdsourced an enormous family tree and boom, came up with something unique," said the study's senior author, Yaniv Erlich, a computer scientist at Columbia University and Chief Science Officer at MyHeritage, a genealogy and DNA testing company that owns, the platform that hosts the data used in the study. Published in the journal Science, the new dataset offers fresh insights into the last 500 years of marriage and migration in Europe and North America, and the role of genes in longevity. From millions of interconnected online genealogy profiles, researchers have amassed the largest, scientifically-vetted family tree to date, which at 13 million people, is slightly bigger than a nation the size of Cuba or Belgium. Thanksgiving gatherings could get bigger -a lot bigger - as science uncovers the familial bonds that bind us.