The length of life of grandparents and great grandparents would have little to do with our longevity. According to a US study, the length of our life would depend on the genes for only 10%. They are much more important lifestyle, environment in which one lives and feeds. Proof? The analysis of over 439 million individuals, aimed at discovering how important genes are for lifespans.
The Calico Life Sciences researchers have selected the genealogical trees of more than 400 thousand individuals. They went back in time, looking for birth and death dates of their ancestors, but also the places where they lived. They then looked for longevity genes, comparing blood relatives and individuals from different families. From what emerged, genes would have a reduced influence on individual longevity.
The genetic heritage in common influences longevity for only 10%. If we also take into account data from acquired relatives, the percentage drops again and even reaches 7%. According to the analysis, husband and wife have a much more similar life span. What is surprising, however, is this also applies to the brothers-in-law. The reason? Perhaps the so-called "selective couplings".
With selective couplings we indicate the tendency of brothers and sisters to choose similar partners. The brothers-in-law would then tend to have in common ethnicity, tastes, cultural level and lifestyle. This would affect their life expectancy much more than the genes, explaining why the brothers in law would have a similar life span.