The key to immortality is found in several animal species. Like some kind of jellyfish or hydra, a relative of anemone, able to regenerate, even if it is dismembered.

Each part of it will grow into a completely new hydra. But why is death inevitable for most animal species, including humans?

Aging, wear and tear of the body is a “dynamic exchange” between reproduction and cellular maintenance.

First, organisms use their resources to grow and maintain good health, creating a strong and healthy organism. After puberty, the emphasis is on reproduction. And since resources are limited, this comes at the cost of good health.

Today scientists have interpreted the inevitability of death. When organisms reach sexual maturity, natural selection weakens and the aging process begins, leading to death.

But this is not to make room for the next generation, explains Alexei Maklakov, professor of evolutionary biology at the University of East Anglia. It’s just that our genes are filled with mutations, either by accident or due to external factors.

“Before we reach puberty, any mutation that limits our reproductive ability or kills us before we reproduce is an evolutionary flaw and is rejected by natural selection,” adds Gabriela Kounturidis, an evolutionary biologist in the Department of Anthropology at the University of Oxford.

“Reproduction, the ability of an organism to pass on its genes to the next generation, is what keeps us healthy and prosperous. After a productive age, from the point of view of natural selection, any attempt to remain in good health is meaningless. That is why the genes that would contribute to this are not chosen for wider dissemination. We would like to stay alive, but natural selection does not contribute to this, since we have nothing more to give to future generations.