Immortality has always been a great interest in humans, whether it’s the superpower, the philosophy, or the future possibilities that could come. And yet, no matter how much we think of it, it still seems to be out of our reach. The thing is, scientists also take a great interest in the possibility of immortality and whether human anatomy could support such an idea. Several experiments have been conducted to understand immortal species and test whether humans could ever be able to do the same.
By immortal species, take hydra, for example. Hydra are made of stems cells that divide to produce new cells once the old ones die. This makes them stay young forever. However, hydra aren’t the only organisms that do this. The planaria, a type of worm, also produce new stem cells, called neoblasts. Unlike hydras, which can reproduce sexually and asexually, planarian worms regenerate themselves because of a need to reproduce. Planaria lack a type of cell called a germline cell, which is used in sexual reproduction. As a result of that and their need to grow in population, they reproduce asexually, much like other organisms.
These organisms aren’t the only species that can rejuvenate themselves. In fact, one of the most well-known rejuvenators are the Turritopsis dohrnii, or the immortal jellyfish. Surprisingly, when these creatures feel a threat in their system, like starvation or fatal wounds, they go back to being a polyp again. What these jellyfish do is absorb their tentacle and outer layer to form a ball. Once formed, this ball drops to a surface within the ocean. Within a few days, the ball transforms into a polyp again, and will eventually expand even more to become a medusa, or an adult jellyfish. This cycle continues on, except if they are eaten.
Although these organisms seem like the gateway to human immortality, there is one glaring difference between us and them--complexity. Hydra and planaria are predominantly stem cells and a smaller body, hence why it is easier for them to renew their cells. However, humans have multiple varying cells in their body, with different functions for each. Renewing all of these makes it hard for our cells to divide like theirs. Instead, our cells go through apoptosis, or cell death. Even immortal jellyfish are simple creatures with limited organs. Nevertheless, our abundance of cells is unable to stop scientists from continuing their research.
Although our anatomy cannot naturally support immortality, technology may have the answer. Many of these proposals focus on the restoration of brain or neural cells, rather than the whole body, and still aren’t possible with the current technology, yet they are still worth some attention. Much like planaria, scientists have innovated an idea in which humans use AI to store all the data within their minds. Once the body dies, this AI can redesign itself to continue living. In a sense, our minds will live past our bodies. In order to test if this idea is in any way possible, researchers have plotted the 302 neural pathways in a roundworm and programmed the information from them to a robot. The experiment proved a success, with the robot behaving unusually like a roundworm. Though mapping our 86 billion pathways may be a more vexatious task, it still proves to be possible.
Instead of relying on AI, researchers at Yale School of Medicine decided to experiment on deceased pigs. With a lack of blood flow and oxygen in the brain, the functions in the rest of the body declines until the organism is dead. With technology that pumps fluid, which mimics blood, oxygen will continue to travel to the brain after death, causing post-mortem life. This life can only exist for a couple of hours with our current technology, but the system was able to stop apoptosis within the pig brains. If this technology advances more, then the complete brain structure and cellular activities can continue on. This doesn’t mean that the technology is without flaws. The electrical activity in the brain, responsible for consciousness and extensive body functions, is not possible with this technology. This is one of the most important aspects, the reason that would make human immortality worth it.
That still doesn’t mean that we should give up on immortality. Setting aside the fact that, if humans are immortal, we would experience the end of the universe and the consequences resulting from our disregard for the planet, our ability to come so far with research and technology still doesn’t end here. With more research in understanding the human mind and AI, there is still a chance to change our anatomy and live eternally.