There is talk about immortality. Will we use the immortal jellyfish, which turns its entire body into essentially an embryonic state, or the axolotl, which can turn specific cells into such a state and regrow limbs? Perhaps both. We may very well be able to form new cells for everything that wears out in the body, thus not only becoming immortal, but forever young.
There are some drawbacks to this, despite the obvious ones of overpopulation and social unrest due to cost (which is a story I am interested in writing).
The first drawback is that you WILL lose muscle memory. They are finding that a lot of our information is not actually stored in the brain, but in the muscles and nerves. For instance, if I had to regrow my left hand, I would essentially have to learn how to play guitar all over again. Sure, it would be in my head, but I would need to retrain my fingers. In fact, if you regrow limbs, you’ll essentially need physical therapy to learn how to use them again. It is feasible that they will find a way around this, however, but I’m not sure how.
The second is more serious. It doesn’t matter how we achieve immortality; we could regrow an entire body and have a brain transplant; we could regrow an entire body and figure out how to implant the information from one to the other; we could simply regrow every organ/limb/cell needed and transplant them; but no matter what we do, the human brain is not wired to achieve immortality. The mind itself will age, EVEN if we manage to grow new brain cells and replace the old ones. It is the information that does it; after a hundred years, our brains are going to have real difficulty storing and accessing memories. This is one of the reasons people have memory issues as they get older. Despite the amazing wonder that is the human mind, it has limitations.
This second drawback, the lack of storage space in the brain, can probably be overcome. I believe the only way we’ll be able to achieve immortality AND retain our sanity is through cybernetic augmentation. That’s not to say we’ll all connect to the internet or have super strength or junk like that. Nor is it to say we’d have computer chips in our heads. Rather, I think nanotechnology would be involved. We would essentially have little bots that go through our brains on a regular basis and erase old information through restoring the cells, but taking the information erased and putting it into some sort of database that our minds would have access to. There would likely be some things that remain: core memories, recent memories, recognition of family and peers, etc. Some things might be erased completely: the trip to the store 20 years ago to pick up milk. Anything of importance, however, would be stored. The way we think would change. Instead of accessing memories, we’d be accessing a program that would draw out the pertinent memories from a database. Our brains would change to learn how to interact with the program, or perhaps the program would have to learn when to interrupt the brain’s natural process of trying to recall information. I think this merits more research…