The scientific team wanted to test the hypothesis that the Y chromosomes cannot protect the body from harmful mutations in the X chromosomes. It is assumed that the second copy of the sex chromosome is able to correct DNA changes and even replace its “harmed” pair.
The scientists compared the totality of chromosomes with life expectancy in males and females of 229 species of animals.
“We have studied the life expectancy of primates, other mammals and birds, as well as reptiles, fish, amphibians, spiders, cockroaches, grasshoppers, beetles, butterflies and moths,” the Phys.org portal quotes one of the study authors, Zoe Kirokostas.
It turns out that individuals with an identical pair of chromosomes live on average 17.6% longer. Depending on the species, such a homogamous set of chromosomes can be in both male and female individuals.
Thus, males of birds, butterflies, and moths are determined by ZZ chromosomes, while females have ZW chromosomes. In this case, male life expectancy will be longer.
In humans, women carry XX chromosomes and therefore they live longer, the scientists explain.
As the researchers noted, if long-livers were males, they only survived females by 7%. And if they were female, this indicator reached almost 21%.
Photos are from open sources.