Genetics has far less influence on lifespan, finds study

The study suggests that the heritability of lifespan is well below past estimates, which failed to account for our tendency to select partners with similar traits to our own.

By: Editorial Team | | Published: November 9, 2018 3:43 pm

Genes may not help you live long. © Shutterstock

How long we live tends to run in families we believe, but genetics has far less influence on lifespan than previously thought, according to a new study. Yes, our DNA plays a significant role and our environment too. The study has been published in the journal Genetics. The researchers analyzed an aggregated set of family trees of more than 400 million people. According to the IANS report, the team used online genealogy resource with subscriber-generated public family trees representing six billion ancestors.

The lead author Graham Ruby, from Calico Life Sciences a US-based research and development company reportedly said that they can potentially learn many things about the biology of ageing from human genetics, but if the heritability of lifespan is low, it tempers our expectations about what types of things they can learn and how easy it will be. She also said that it helps contextualise the questions that scientists studying ageing can effectively ask.

Heritability measures how much lifespan can be explained by genetic differences, excluding differences like lifestyle, sociocultural factors and accidents.

While previous estimates of human lifespan heritability have ranged from around 15 to 30 per cent, in the new study it was likely no more than seven per cent, perhaps even lower.

Removing redundant entries and those from people who were still living, they stitched the remaining pedigrees together included more than 400 million people, largely Americans of European descent.

Each of them was connected to another by either a parent-child or a spouse-spouse relationship.

They focused on relatives who were born across the 19th and early 20th centuries and noted that the lifespan of spouses tended to be correlated, more similar than in siblings of opposite gender.

Comparing different types of in-laws, they found that siblings-in-law and first-cousins-in-law had correlated life spans, despite not being blood relatives and not generally sharing households.

The researchers also reportedly said that the finding that a person’s sibling’s spouse’s sibling or their spouse’s sibling’s spouse had a similar lifespan to their own made it clear that something else was at play.

They also explained that the answer might lie in assortative mating. People tend to select partners with traits like their own.

Published : November 9, 2018 3:43 pm

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