Online genealogies are helping researchers analyze population-level genetic trends. | MyHeritage
Taking advantage of an online public database shared by genealogy enthusiasts, researchers have created a massive, crowd-sourced family tree. It tracks the births, marriages and deaths of millions of people, shedding light on the impacts of war, culture and disease over the last several centuries.
The results are featured in a study in the March 2 issue of Science.
Many people enjoy constructing their own family trees, digging deep into their roots to understand their ancestors. Looking at the connectivity between people can also be helpful for researchers examining genetic and cultural patterns.
In 2010, Yaniv Erlich was leading a group of researchers at Whitehead Institute when he read about using pedigrees, essentially family trees, as a means to study genetics. He was already passionate about using family trees, having submitted his own data to one of the largest online public genealogy databases, Geni.com. “Being a Geni user for some time, I thought that Geni can be a wonderful alternative to traditional methods for collecting family trees that do not scale well,” explained Erlich, who now works as the chief science officer of MyHeritage (the Geni parent company) and is an associate professor at Columbia University.
With permission, he and his colleagues analyzed 86 million publicly available profiles from the website, which mostly reflect the histories of people in Europe and North America. They cross-referenced the family tree they created with publicly available death records from Vermont to confirm that the tree accurately reflects participants’ histories.
The family tree they assembled shows the darker moments in recent human history; for example the massive waves of death during the American Civil War, World War I and World War II. But the tree also shows a reduction in child mortality during the 20th century, likely reflective of medical advances.
One of the analyses that Erlich and his team performed using the data focuses on the heritability of longer lifespans. Previous studies looking at families and genetics have estimated that the heritability of longevity is roughly 25%. By analyzing the Geni.com data, Erlich found that heritability of longevity is substantially lower, at 16%.