Calico Life Sciences, is a research and development company whose mission is to understand the biology of aging. They are part of Alphabet Inc. family of companies and the parent of Google. Calico teamed up with scientists from Ancestry and used publicly available pedigree data from Ancestry to estimate the heritability of human life span. Starting from 54 million subscriber-generated public family trees representing six billion ancestors, Ancestry removed redundant entries and those from people who were still living, stitching the remaining pedigrees together. Before sharing the data with the Calico research team, Ancestry stripped away all identifiable information from the pedigrees, leaving only the year of birth, year of death, place of birth (to the resolution of state within the US and country outside the US), and familial connections that make up the tree structure itself.
They ended up with a set of pedigrees that included over 400 million people—largely Americans of European descent—each connected to another by either a parent-child or a spouse-spouse relationship. The team was then able to estimate heritability from the tree by examining the similarity of life span between relatives. Heritability is a measure of how much of the variation in a trait—in this case life span—can be explained by genetic differences, as opposed to non-genetic differences like lifestyle, sociocultural factors, and accidents.
They used mathematical and statistical modeling and focused on relatives born across the 19th and 20th centuries. They found heritability estimates for siblings and first cousins to be about the same as previously reported. They also found that the life span of spouses tended to be correlated—they were more similar, in fact, than in siblings of opposite gender.
They also found that siblings-in-law and first cousins-in-law had correlated life spans even though they were not blood relatives and not sharing the same household. Interestingly, people tend to select partners with similar traits to themselves—including longevity. The basis of this mate choice could be genetic or sociocultural—or both. They found that life span heritability was found to be below 10 percent or lower and therefore how long you live has less to do with your genes than you may think.
The press release from Calico Labs is available at:
The article was published in the Journal Genetics and may be read at: