When you look at all the cables behind any collection of devices, the way they are tangled indicates the order in which they were installed and moved around. Unless someone took the initiative to straighten the mess out.
Apparently, the human body is the same way. And no one has gotten around to cleaning up the mess. But all the wires work well enough.
How do we know if the wires work well enough? For example we can talk so our communication tools work well enough, but what if we were suppose to communicate telepathically, hence this form which works well enough limits our ability to even think properly? Or let's say if the wiring had a little tweak in it we could significantly expand our lifespan?
I believe the bigger ethics question is "Would we want to extend the length of an average life?"
We can easily surmise that saving our parents and grandparents would be an awesome thing (in many circumstances). As an individual choice, having loved ones around longer is good.
It gets stickier ethically the further we move away from the individual and go more towards populations. Where do we put them? Do we warehouse them? How do we manage to feed the bigger population? What will they do, as they must work?
And then there's the big scary word: Eugenics. It was advocated in the 1920's by Sanger, and later by the Nazis. However nasty the connotations are, China is currently going down this very path by taxation and restriction on number of children. Discussions that we thought were closed will come reopened rather quickly, when we have 10+ billion people here. Hopefully, we'll be mature, as a citizen of the world, to discuss these problems.
I think these questions could be answered if we truly spent enough ressources on them. We can scale up as opposed to horizontally. Food could be produced in labs and have more nutrients and taste better.
However, the hard facts we are dealing with today is the aftermath of the Baby Boomers. Normally, when we deal with population graphs, we see a huge base of young, a smaller base of young adults, smaller base of mid adults, and a small/pinnacle of elderly. It's supposed to taper off into a long tail.
Instead, we in the US (unsure about other cultures and areas) a huge bulge around 55-65. Social programs are meant to subsidise the elder through the younger. However in this situation, there's not enough younger to pay for the same care the elder have been receiving. So you either raise the age cap, or reduce service. And, AARP makes sure the second choice doesn't happen.
And about the food quip: back in 2000, the global food output was enough to feed 12 earths of people, yet people still died of hunger. Overall resource maintenance and allocation is the bigger, and unsolved problem.
Presumably if we could extend life, we could also extend the period of life in which you can produce and create useful things. There would be little point extending lives if it meant you spent an extra 30 years confined to a bed with no memory of your identity.
Upper middle class and above have little to no qualms about throwing scads of money at a little bit of extra time here, even if the quality of that time is approaching 0. And in the baby boomers case, they expect the government to send in their due. When that comes, though, we will not be able to afford it.
It's kind of what we talk a lot about in the entrepreneurial sense: We try to convert time to money in a reproducible sense. However, the older you get, money depreciates to 0 (dead people have no use for money), so you run that equation backwards, with large inefficiencies.
But this kind of talk seems to piss off the bulk of downvoters. So be it.
Because I don't think that "humanity tends to adapt to higher population densities as it needs to" is an appeal to emotion, but I do think that accusing someone's argument of being an appeal to emotion in what is traditionally a rather intellectual discussion venue is a pretty heavy accusation.
Apparently, the human body is the same way. And no one has gotten around to cleaning up the mess. But all the wires work well enough.