Jakarta –
There is a big difference between the rate of aging of mammals (including us) and the rate of aging of many species of reptiles and amphibians. This difference, according to one scientist, may be due to the dominance of dinosaurs millions of years ago, at a critical period in mammalian history.
Microbiologist João Pedro de Magalhães of Birmingham University in the UK, explains the ‘longevity barrier’ hypothesis in a newly published paper.
He argues that when dinosaurs ruled the Earth, much smaller mammals had to be able to reproduce quickly in order to survive. This means that genes that had a longer lifespan may have been discarded as evolution progressed.
“Some of the earliest mammals were forced to live at the bottom of the food chain, and likely spent 100 million years during the time of the dinosaurs evolving to survive through rapid reproduction,” said de Magalhães as quoted by Science Alert.
“Evolutionary pressure over a long period of time, I think, has an impact on the way humans age,” he said again.
Published research notes that our ancestors in the eutherian mammalian lineage appear to have lost certain enzymes by the time of the dinosaurs, enzymes that repair damage caused by ultraviolet light.
Interestingly, even marsupials and monotremes lack at least one of three UV repair enzymes, known as photolyases. It’s hard to say whether this has anything to do with their relatively shorter life spans.
One possibility is the disappearance of mammals, as they became more active at night to stay safe, and millions of years later, we replaced them with sunscreen. This is an example of the repair and restoration mechanisms we should have in place.
There are also other signs. For example teeth. In certain reptiles, including alligators, they can continue to experience teething throughout their lives. While humans cannot do it. Again, perhaps this is the result of genetic selection hundreds of thousands of years ago.
“We see extraordinary examples of repair and regeneration in the animal kingdom. That genetic information was not necessary for early mammals that were lucky not to become food for T. rex,” said de Magalhães.
A number of mammals do celebrate triple-digit birthdays, including whales and us humans. Whether we did so under constraints imposed by our short-lived ancestors, or we have somehow evolved to be unaffected by our ancestors, this could be a target for future research.
Understanding more about the factors behind aging is always useful in fighting age-related diseases, including dementia and stroke, and the genetics behind ‘longevity barriers’ may have more lessons for us here.
“While currently only a hypothesis, there are many interesting angles to take, including the prospect that cancer is more common in mammals than in other species due to the rapid aging process,” said de Magalhães.
Watch Video “4 Dinosaur Diseases That Humans Also Experience“
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2023-12-09 23:15:25
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