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José Cordeiro, living forever has been a dream of human beings since their beginning. Currently, we live for around 100 years, whales and turtles live even longer. Is that fair?
Different species can have vastly different lifespans. There are trees that can live for thousands of years, some algae as well. Among the animals there are some clams that are 700 years old, sharks that are 500 years old – we even found harpoons from the Middle Ages in a living shark. Whales and turtles live over 200 years. On the other hand, we have little mice, which only live for two years. We are biologically quite similar to other mammals; we share around 90 percent of the genome with them. But a mouse only lives for two years, while a whale lives for 200 years.
Have there been any successes in making animals live longer?
Thanks to experiments, we have been able to double the lifespan of mice; there are now some mice that live for five years, which would be equivalent to a human living for 200 years. Flies like the Drosophila melanogaster live four times as long now, which would be equivalent to a human living for 400 years. Methuselah worms have had their lifetimes multiplied by a factor of 10 – that would be a human lifespan of 1000 years. This progress has happened in the last few years, and it’s just the beginning.
How does it work?
Scientists have discovered that aging is flexible, and that it can be reverted. In 2012, the Nobel Prize in Medicine was given to a Japanese scientist called Shinya Yamanaka, who discovered four genes that control aging, among more than 20 000 genes in mice. It is now possible to modify these genes to accelerate, stop or reverse aging. Yamanaka was able to reverse aging at the cellular level in 2006, and other scientists at Harvard University did it at organ level in 2020, demonstrating that it is possible to rejuvenate the eyes of mice.
Can this be applied to human beings?
There are several biotech research companies like Altos Labs, financed by billionaires like Jeff Bezos, that have the objective to rejuvenate cells, organs and eventually complete organisms. There is a lot going on: Scientists are experimenting with gene therapies, cell therapies, organ transplants, organ 3D printing, nanobots in the circulatory system, young blood transfusions, or immuno therapies, amongst others. There are also other treatments that have already shown to extend both the healthspan and the lifespan of model animals like worms, mosquitoes and mice.
Peter Thiel said1: «The germ cells don’t die, they reproduce, but we, the carriers, die. This is shocking on the one hand and exciting on the other». Do organisms already carry a spark for immortality?
Indeed, there are biologically immortal cells, and there are also biologically immortal species – in the sense that they do not age.
A species of jellyfish called Turritopsis dohrnii seems to be immortal.
Yes, and there are Hydras and Medusa who do not age biologically, so they are biologically immortal. They can still die or be killed, but they do not age. Humans also have cells that do not age, as all multicellular organisms do – they are our reproductive cells, the germ cells, which produce sperm in men or eggs in women. When we die, germ cells die with us, but not because they age. Cancer cells also do not age: they are mutations of aging cells that stopped…