In case anyone is still reading this, I'd like to add to this. Think about humans in terms of corporate employees. A single human in today's society costs an

In case anyone is still reading this, I'd like to add to this. Think about humans in terms of corporate employees. A single human in today's society costs an absolute fortune to raise to adulthood in resources. It takes a lot of investment by society and the parents both to have the child, then to educate it. It takes many years of education to turn the child into a citizen. It takes more education (college) to turn the citizen into a highly productive one. Then, assuming all goes well, they go into the workforce and then there's a lot of ramp-up time, gaining expertise, etc. If they go the postdoc degree route, that's more time. Even worse, look at all the training/education needed for specialized doctors and surgeons. People aren't usually really productive until they're 25-30 years old. Then they only have so many decades until they're too feeble to really contribute a lot, and during that time they're expected to have kids of their own, which is basically a second job. (Even worse, women need to have those kids in their 20s-30s, which is exactly the wrong time career-wise.) In short, the actual overhead needed to produce useful citizens in today's complex society is enormous, relative to the total lifespan of that person. It wasn't a problem in the hunter-gatherer days because we didn't need much education to learn some simple non-written language, nor much training to go throw a spear and kill some animals and cook them. Things are very different now. Extending useful and healthy human lifespans would change that equation, and be a huge boon for modern society. Just look at how many women end up postponing having children, or giving up on it altogether, because it just doesn't fit in with a high-paying career. As a result, developed nations are seeing negative population growth, which isn't sustainable.