In this zombie thread (Why Did Evolution Do This? - Factual Questions - Straight Dope Message Board), on the reasons some animals use hemocyanin in their blood instead of hemoglobin, Sockmunkey mentioned that the optic nerve, the birth canal, the back, and possibly the wrist are all suboptimally constructed in that it’s not too hard to think of a better design for these body parts.
Now, I understand that evolution does not have to create perfection, so that’s not the question I’m asking, but I am interested in what these suboptimal parts are and how they might be improved. So, what else in the human body doesn’t work as well as it could? And how might it be improved if some sort of biological engineer got ahold of it?
The spine, for example, seems really crappily built, but what would it take to fix it? Would it be better if it weren’t curved? Would the hips have to change as well? Would it be better if we had another spine in the front as well? I have no idea, but I greatly welcome your ideas and insights in critiquing nature’s engineering, as it were.
Teeth. We get one set only good for our first few years, and then another that’s supposed to last for 70? That works out so well for most of us.
We ought to get more replacement sets like a shark does…maybe we could add a bit of shark DNA to the mix; if you can add jellyfish DNA to animals to make them glow, extra teeth buds should be doable too. As for experimenting on people, Max seemed pretty much okay (psychically) with a dash of feline DNA, right?
Heart pumps blood and is therefore chock full of blood, but gets its blood from the coronary arteries - small offshoots from the aortic root that get obstructed and cause heart attacks.
Pancreas. Ticking time bomb of pancreatic enzymes waiting to digest you from the inside. Should have a vent to the outside world.
Bile duct. Why route it via the pancreas and get pancreatitis from gallstones? Why not have it meet the duodenum someplace else.
The first thing that springs to my mind is the placement of the testes. Yes, I know they need to be at lower than body temperature to function, but surely there’s a better way than dangling them in a little sack between my legs?! Countless youtube videos attest to the ease with which a man can lose his ability to reproduce, and yet they dangle there, seemingly oblivious to the perils around every corner. I may have overstated my point there somewhat, but damnit, evolution owes me answers!
Also the tongue of most humans is far too short. Why can’t I have a giraffe like tongue to clean my ears/nose out with?
Toenails which, if not cut correctly, grow into the toes from whence they came. (Okay, we probably do this to ourselves by wearing shoes and socks most of the time. Do warm countries (more inclined to wear open toed footwear) have lower ingrowing toenail rates than similarly developed countries? Does anyone keep records?)
I’d think of more, but I have to take my medicine and lie in a darkened room for three hours while something unmentionable happens to my lower half now. Will check back later
To those of us “of a certain age,” the most obvious answers are knees and backs. Our knees can’t support us as the cartilage wears out, and our backs are prone to all sorts of problems.
And why can’t the brain continue to function and grow into old age?
And childbirth. Why does it have to be torture for the woman?
Urethras, especially on women. They’re so damn short, and they’re right there inches away from the anus and millimeters away from the vagina, practically begging for urinary tract and bladder infections. As someone wittier than I once said, “If God was a city planner he would not put a playground next to a sewage system!”
Knees, as mentioned.
The pancreas, not only because it makes all those digestive enzymes, but because it’s so damn diffuse that when it gets cancerous, it’s next to impossible to get the whole damn thing out. If I was designing it, it would be a nice hollow organ with firm sides, like the stomach or gall bladder, not this jello wrapped in cellophane shit.
Oh, yeah…shit. We can’t make all the vitamins we need, so instead we’ve evolved to carry a host of deadly bacteria in our bowels to make them for us. Good so long as they stay put, but one little teeny tiny pinprick hole in your intestine and it’s peritonitis time. And even if that doesn’t happen, we’ve got poop to deal with, which, having said symbiotic bacteria in it, kills people if they get it on their food or in their water. Yet it’s sticky stuff, which would suggest that pooping IN the water would be the best way to go about it, only then evolution invented dysentery.
Intelligent Creator, my ass.
(I’m also not happy with my ass, in fact, but that’s probably fodder for a fashion thread.)
Well, that’s not really suboptimal design. Knees and backs are designed to last for a normal human lifespan; it’s not their fault we’re all living longer.
I think many adult health issues could be solved if adult tissue could generate stem cells- and that would include many knee and back problems.
I’ve always thought it was shoddy design to have the spinal cord so exposed, though. I mean, the heart and lungs are protected by the ribcage; why can’t the spinal cord run down the middle too?
I’d say eyes. I think, in my life, I know maybe 10 people or less who didn’t need corrected vision at some time in their lives. I’d say about 95% or more of the people I meet use some sort of correction, and some of them need extra correction, like bifocals. This is not including all the people with eyes that were damaged through accident. My theory is that failing vision should have been weeded out of the dna pool centuries ago, but because of glasses/contacts/lasik, they’re still there.
Two chambers of the heart are full of blood with a minimum of oxygen, so it would by disastrous to rely on that blood to oxygenate the right atrium and the right ventricle.
So you children can have a brain big enough to operate an Xbox 360.
Some mornings, like this one, I feel distinctly sub-optimal. I’m sure all these aches and pains could be desinged out. Things like joints are an evolutionary compromise, they are built to be light, not necessarily to last.
A lot of poor eyesite is due to modern technological developments that cause people to spend large amounts of time with their eyes focused in a single plane. So thats less a design flaw and more our using our eyes for things they weren’t designed for. Spend less of your time reading the Straight Dope and more hunting zebra on the plains of Africa and you wouldn’t have to wear glasses.
Our brains perform their high level processing on the outer surface, which is why they are so convoluted and which contributes to their large size. As opposed to birds, which perform processing at various nodes throughout their brains and can therefore get more work out of a smaller brain than a mammal.
As for spines, two improvements come to mind. The first is to move it into the central core of the body instead of being exposed as it is. The second is to have two spines; the load bearing spine, and one which is just the armor for the spinal cord.
Our limited senses. Animals have better senses than we do, and some have senses we don’t have at all.
Our bodies and brains are not built to deal with surfeit. We crave energy rich foods when we have more than enough already. a better design would be a “smarter” appetite; where we crave what we need, instead of reflexively craving what out ancestors thousands of years ago needed.
Our (and other animals) ability to estimate rewards and consequences over time is screwed up. We tend to jump at immediate rewards while downplaying long term consequences; and we tend to have trouble putting up with immediate difficulties for a long term major reward.long
Childbirth. Either move the birth canal so that it doesn’t have to squeeze a baby between heavy bones, or add joints to the pelvis that allow it to open up during birth.
Thumbs on only one side of the hands. Turn the pinky finger into a second thumb.
And in fact there ARE mammals that have internal testes; our ancestors just didn’t pick up the right mutations.
One big problem is our inability to synthesize Vitamin C. If we don’t have it regularly, we get scurvy. Seamen refgularly got scurvy on long voyages. Ironically, the rats on board didn’t. Because evuidently our inability to make Vitamin C is the result of a genetic accident that happened some time back in our ancestry.
Fortunately, our ancestors lived in a region where vitamin-C-producing plants were plentiful. Unfortunately, this has been a limiting feature for man’s Conquest of the Globe. It’s particularly annoying that vitamin C degrades or decays so easily. Even after people figured out that scurvy could be prevented by taking certain fruits and juices, it turned out that the juices lost potency very rapidly.
I knew it! Now I have a use for that time machine that’s been sat in my shed since next year.
What genus do I need to get our ancestors to breed with for best results, do you think?
ETA: I’m torn between Sloths and Armadillos. Might have a poll…
I don’t think are senses are so much sub-optimal, as a compromise. If we had better senses we might have less brain-power available for other tasks. Eagles have amazing vision, but are pretty stupid compared to crows. On the other hand, the blind spot is a clear case of sub-optimal design.
Sure, good point. I could still design a better system. Hell, there’s an entire non-coronary sinus in the aorta that’s going to waste, maybe I’ll tap into that. For that matter, why don’t the internal thoracic arteries naturally anastamose with the coronary arteries from the get-go.
I’ll do all this after I redesign the eyeball to be more like a squid’s eyeball, with no blind spot. This is assuming that I’m involved in designing Reality 2.0.