Feeling Your Age? Blame the Dinosaurs, Scientist Argues

The human aging process causing your sore joints may have been influenced by the dinosaurs, researchers have found.

This "longevity bottleneck hypothesis" suggests that the evolutionary pressure that dinosaurs put on mammals during their Mesozoic Era reign 100 million years ago may have led to the loss or deactivation of genes allowing for a longer life.

This may have led to our decreased ability to repair DNA and regenerate tissue compared to our amphibian or reptilian cousins, according to a new paper in the journal BioEssays.

"The 'longevity bottleneck hypothesis' may shed light on evolutionary forces that have shaped mammalian aging over millions of years," Joao Pedro de Magalhaes, a professor of molecular biogerontology at the Institute of Inflammation and Aging at the University of Birmingham, said in a statement. "While humans are among the longest-living animals, there are many reptiles and other animals that have a much slower aging process and show minimal signs of senescence over their lives."

Aging—or senescence—is triggered by a number of factors including slow degradation of chromosomes and running out of stem cells. However, scientists still aren't sure exactly what causes aging, with some suggesting that it's caused by an accumulation of genetic damage, and others positing that some genes are primed to provide an advantage in earlier life at the cost of later life function.

The reason mammals appear to age much faster and therefore live less long than reptiles and amphibians has been a long-pondered mystery, but de Magalhaes's theory may explain it.

"Some of the earliest mammals were forced to live towards the bottom of the food chain and have likely spent 100 million years during the age of the dinosaurs evolving to survive through rapid reproduction. That long period of evolutionary pressure has, I propose, an impact on the way that we humans age," de Magalhaes said.

"We see examples in the animal world of truly remarkable repair and regeneration. That genetic information would have been unnecessary for early mammals that were lucky not to end up as T. rex food. While we now have a plethora of mammals—including humans, whales, and elephants—that grow big and live long, we and these mammals live with the genetic constraints from the Mesozoic Era, and we age surprisingly faster than many reptiles."

"While just a hypothesis at the moment, there are lots of intriguing angles to take this, including the prospect that cancer is more frequent in mammals than other species due to our evolutionary history," he said.

There is a huge amount of research into the field of slowing human aging, with many people hoping to extend their lives further than we can naturally live.

"Several scientists have already modified the genes of organisms to make them live longer—mice, the C. elegans worm, and fruit flies, among others—and the genes they manipulated are shared with many species, including humans," John K. Davis, a professor of philosophy and bioethics at California State University, Fullerton, told Newsweek.

"I don't know whether manipulating the same genes in humans would have the same effect—there are too many other factors that might affect this—but it's certainly possible that these experiments may lead to life extension techniques that work in humans."

However, these life-extending breakthroughs are still a long way off.

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