A recent study using 54 million family trees loaded in Anestry.com purports to show the genetics have much less influence on lifespan than previously thought.
Previous studies suggested that lifespan is about 30% heritable, due to direct genetic factors passed down through families. However this new study using family data from 400 million people living in the 19th and 20th centuries reveals a different story. Using mathematical models on this massive database allowed researchers to estimate that genetics contributes less than 10% to lifespan. The major actor that accounts for longevity running in families is “assortative mating” - the concept that people of similar characteristics, such as wealth - tend to marry. "What assortative mating means here is that the factors that are important for lifespan tend to be very similar between mates," said Graham Ruby, PhD, a researcher involved in the study. At one level, this supports the concept that genetics is not fate. But does this mean we can escape genetics? It is never all-or-nothing: what if assortative mating, the selection of characteristics in mate, is driven by genetics, too?!