Heredity or environment?
Scientists have established the main factor of longevity
The results of a nearly twenty-year study of wild sheep in Scotland have shown that telomere length correlates with life expectancy, determined mostly by heredity, and not their preservation, which depends on living conditions and the environment. The article was published in the journal Proceedings of the National Academy of Sciences (Froy et al., Heritable variation in telomere length predicts mortality in Soay sheep).
The length of telomeres – the end sections of chromosomes – is considered an important biomarker of health or aging of the whole organism. The shorter the telomeres, the higher the risk of death – this is a universal rule for all vertebrates. However, until now it has not been completely clear what influences telomeres more – heredity or external factors.
Solving this issue requires long-term observations over the course of several generations, and such studies are difficult to conduct in humans. Therefore, scientists from Norway, Great Britain and Canada, led by Daniel Nussey from the Institute of Biology of the Norwegian University of Science and Technology, chose for their observations a shorter-lived species – a closed population of wild sheep of the Soai breed living on the islands of Scotland.
For almost twenty years, the authors collected data, and then, using multidimensional quantitative genetic models, analyzed the relationship between telomere length, their preservation and subsequent survival of animals, depending on a variety of factors.
As a result, it turned out that life expectancy correlates with the length of telomeres and does not correlate with their safety, that is, the degree of exhaustion. At the same time, the first parameter is directly related to genetic inheritance, and the second is related to environmental factors such as stress or nutrition.
"We found no evidence that telomere depletion is associated with an increased risk of mortality," the authors write. – Instead, we found that interindividual differences in average telomere length are associated with an increase in life expectancy. Our analysis shows that this correlation between the average telomere length and an individual's lifespan has a genetic basis."
The authors believe that their discovery suggests an important role of genetics in the control of longevity and note the need to continue research by studying the evolutionary aspect of this control.
Portal "Eternal youth" http://vechnayamolodost.ru