Originally shared by Russ Abbott
Josh Mitteldorf, who is no kook, challenges antagonistic pleiotropy, the theory that genes that shorten life must have some positive function — or they would have evolved out of the genome.
But there are multiple examples of genes, which when deleted extend life with no apparent negative effects. One of the most recent is a gene called SERPINE1, encoding PAI-1. [When mutated, and made non-functional,] the result is longer telomeres, better insulin sensitivity, protection from cardiovascular disease, and longer life expectancy. [In other words,] SERPINE1 must be regarded as an aging gene, having no purpose (we know of) except to hasten the demise of its owner.
Middeldorf discusses a number of other such instances in other animals.
Why has evolution preserved these genes? No one has come up with a satisfactory explanation.
https://joshmitteldorf.scienceblog.com/2017/11/20/a-dead-theory-still-walks/
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