Not looking for a full redesign, but just design tweaks. Those who believe in Intelligent Design may want to sit this one out for fear of hubris, but those who think the body was made by a committee at best should weigh right in.
I’ll start the ball rolling with: The pancreas. It’s a terrible organ. It’s main job is to dissolve proteins, and it is positioned right in the middle of the body. Any injury to the pancreas, and you begin to digest yourself. This makes as much sense to me as the self-destruct button in the villian’s hideout. The pancreas should have a thick cover and a vent to the outside world - you drink too much, the pancreas gets inflamed, and spurt - out goes pancreatic juice onto the barstoo.
AND another thing - why are the coronary arteries so tiny, and generally why is the blood supply to the heart so pathetic? Two tiny yet essential supply routes for blood for an organ that spends all of its time…wait for it…pumping blood. It seems ridiculous. The heart should have a way of getting all the blood it could possibly want from the ventricles, maybe even through the ventricle walls in little spurts as it contracts and relaxes.
I think the male genitalia could have been thought out a little better. Having these very sensitive bits dangling there ready to be kicked by an enemy is kind of dumb. I know, sperm want to be cool. So, could we maybe design sperm that can survive at a slightly higher temperature, so I can keep my genitals on the inside, at least until it’s time to use them?
Oh, and I guess the appendix has been kept around for backward compatibility or something, but at this version level of Human, it really just increases maintenance costs.
We live too damn long. It is expensive for the individual and for the planet. We need some mechanism to curl up and die after a few years of procreation like a cat or a dog.
Valves in all blood vessels that can cut off bloodflow immediately in case of major trauma.
More internal feedback; “It hurts” just isn’t very useful in telling what’s wrong when I have a headache or stomachache. An “internal nose” that could let you sense your own blood chemistry would be a good upgrade as well.
Enhanced senses ( and more of them! ) in general.
Change the pinky into another thumb, and remove the little toe.
Replace much or most of the lung’s tissues with a symbiotic plant; modified to get energy from blood sugar and not sunlight. It would perform the normal gas exchange functions, but in case of suffocation or just for an extra boost it could directly convert CO2 to O2. No doubt at a serious metabolic cost, but I expect you’ll get exhausted a lot slower than you would drown.
Consciously controlled fertility; you can get pregnant/father a child only as a deliberate choice.
Bones made of something less weak and brittle. Something strong, but that flexes instead of snaps under stress.
Nerves that conduct electricity better and faster.
Fibers on the order of spidersilk in terms of strength ( very strong for their weight, and something we know can be produced organically ) in a three dimensional “weave” throughout the body and an extra thick layer under the skin. Since spider silk is strong enough that it’s been considered a candidate for bulletproof vests, that would make humans much harder to seriously hurt.
A wider variety of colors. Even better, the ability to change color like an octopus ( which are much better than a chameleon ).
Teeth that replace themselves ever 15 years so, instead of once in a lifetime.
Salamander style regeneration.
The elimination of aging.
Internal valves in the nose and ears; both to prevent water getting in and to serve as an eyelid-equivalent against irritating sounds/smells.
Some mammal species have internal testicles, with other ways of keeping them cool than just letting them stick out.
We sort of have this as a manifestation higher order thinking skills. We can comprehend our situation in life and choose to end our lives if we wish. I can’t think of any other animal that would willingly do something to hasten its own demise in the absence of physical illness. Sure, we have to do a little work to get dead, but our intelligence almost guarantees that if we really want to die, we can.
CNS/Skull/Spinal: Intra-cranial shunts to allow the venting of CS fluid in the event of injury or IC bleeding. Additional/redundancies for things like the substantia nigra and other unique brain structures. Para-spinal nerve relays to mitigate spinal cord injuries.
Optical/Aural: Better shunts to manage intra-ocular fluid pressure, better structural and vascular support for the retina. More robust/regenerating hearing.
And maybe a load-bearing, articulated prehensile tail. Maybe not fully loading, but maybe arm-strength.
Another idea; internal and external spines. The heavy external one ( where ours is now, right under the skin ) would be load bearing; the much thinner internal one would the the spinal cord and armor for it. They would only be loosely connected and nearly all stress would impact the outer load bearing spine, meaning that a broken back would be far less likely to result in paralysis.
We should be able to re-grow nerves, even if our internal spinal cord is broken. We should have stronger immune systems and our skin shouldn’t be able to get wrinkles or pimples so easily. I don’t have any, but why hemmorhoids? Who ever thought they were a good idea?
I think some revisons could borrow from other parts of the animal kingdom.
Like sharks, we should have more than two sets of teeth over our lives. What good is it to have a set that is gone before puberty, then just one more for the next fifty or more years?
Like dogs and cats, human females should have a longer cycle. Why do creatures that are large and take require a lot of food and teritory need reproductive opportunities every single month? Twice or three times a year should surfice.
