Researchers' opinion: people die of old age because of dinosaurs
Scientists say that it was dinosaurs that once drove the ancestors of modern mammals into unbearable conditions. For them, longevity became impossible and unnecessary.
Dinosaurs are to blame for the fact that people age rapidly and die of old age. More precisely, the unbearable living conditions they created for distant human ancestors. This is stated in a scientific article onlinelibrary.wiley.com.
The researchers outlined their view on the "longevity bottleneck hypothesis," which suggests that during the dinosaurs' domination of the planet 100 million years ago, the mammals of that time lost the genes responsible for cell regeneration and, as a result, for prolonging life.
Scientists note that humans, although they have a fairly long lifespan compared to other animals, are still significantly inferior to many reptiles, which show minimal signs of aging throughout their lives.
It is believed that aging is caused by the gradual degradation of chromosomes and the depletion of the body's supply of stem cells responsible for tissue regeneration. But the causes and mechanisms of aging are still largely unclear to science.
One of the mysteries is that mammals in most cases age much faster than reptiles and amphibians. The authors of the new study offered their answer to this question. In their opinion, this is the result of the evolutionary changes that mammals underwent in the era of dinosaurs.
At that time, mammals were at the bottom of the food chain, so the only option for their survival as a population was to reproduce as quickly as possible. This was the direction of evolution, but along the way, mammals lost the ability to regenerate, which prevents aging.
"In the animal kingdom, we see examples of truly amazing repair and regeneration. This genetic information would have been useless for the early mammals that were lucky enough not to become food for T. rex. Yet now we have many mammals, including humans, whales, and elephants, that grow and live long lives. We and these mammals live with the genetic constraints of the Mesozoic era, and we age surprisingly faster than many reptiles," the researchers say.