A team of researchers creates a huge family tree of 13 million people, spanning 11 generations.Millions of lay people have given their data to a genealogy website. Researchers have now created the largest family tree in the world and drawn interesting conclusions. The family tree attempts to try and find answers to intriguing questions about the human population.
Researchers have created the largest pedigree in the world: 13 million people, mostly from Europe and North America, have been connected to each other for over 500 years. These are more family members than Belgium has inhabitants.
The researchers around Joanna Kaplanis of the New York Genome Center scoured 86 million person profiles, which had been created on the website Geni.com especially by hobby-genealogists from around the world. Among other things, the team found that genes play a minor role in a person’s longevity.
On average, the family network, which also tracks emigration from Europe to America, extends over eleven generations, the researchers report in the journal Science. To reach a single common ancestor, they would have had to go back 65 more generations.
By structuring the birth, marriage and death dates and places with the help of mathematical theories, the American-Israeli team came to interesting conclusions: Thus, it was found that most Americans found their spouse within ten kilometers before 1750 – during 1950 births mostly 100 kilometers traveled to find the love of their lives.
In addition, before 1850, married more often within the family – on average, a cousin 4th degree. In the past 300 years, more women have changed their place of residence in Europe and North America than men. However, when men migrated, they traveled further than women.
Using a computational model – developed with data from three million relatives born between 1600 and 1910 and over 30 years of age – the team also explored the role of genes for longevity. So far, it was assumed that the genetic material is responsible for 15 to 30 percent for a long life. However, the family comparison showed that only in 16 percent of cases, the decisive factor. Therefore, good genes could only extend life by an average of five years, the researchers conclude.
“That’s not much,” says co-author Yaniv Erlich. “Other studies have shown that smoking can cost ten years to live. That is, some life decisions are more important than the genes. ”
“This is an exciting moment for Citizen Science,” says population researcher Malinda Mills (University of Oxford), who was not involved in the study. “It shows how millions of ordinary people, as enthusiastic genealogists in science, can make a difference.”