A new study from researchers at Ancestry.com and Calico has found that genes have a modest influence on human longevity, Stat News reports. Calico, which is part of Alphabet, was launched to study aging and mortality, and it teamed with AncestryDNA in 2015 to study the genetics of longevity.
The researchers drew upon Ancestry's family tree database to examine the lifespans of more than 400 million people, comparing how long spouses, parents and children, siblings, and distantly related and unrelated people lived. They focused on individuals born in Europe or the US in the 1800s to mid-1900s. As they report in the journal Genetics this week, Catherine Ball, the chief science officer at Ancestry, and her colleagues found the heritability of lifespan to be below 10 percent, and likely no higher than 7 percent.
The researchers add in their paper that what had seemed to be a genetic basis for lifespan could likely be chalked up to assortative mating in which people chose mates of similar socioeconomic status or educational level, which have their own effects on lifespan.
"Right now a healthy lifespan looks to be more of a function of the choices that we make," Ball tells Wired. She adds that their analysis captured dips in lifespan among men that correlated with World War I and then as men and then women took up smoking.