Humans are the product of billions of years of evolution, and yet there are still some problems with our bodies that it would be nice to see nature fix in the next update patch.
Examples:
Pain- While pain seems to be pretty good at removing us from immediate danger, it’s not very good at telling us how much damage we’ve incurred. Stubbing your toe hurts like a mortal wound, yet your body can die from the inside out from cancer and you can feel nothing until the latter stages. .
Fat storage-Probably because living with such abundance is fairly recent, we might have to wait awhile for this one. Why would your body just keep storing fat until you literally die from too much of a good thing? While fat has a real purpose, it seems that our bodies should say enough as enough at some point and just eliminate excess fat as waste. But no, it’s killing you yet your body just merrily continues along, perfectly willing to jack you up to 600 pounds
Better brain-body coordination- as evolved as we are, we’re more of a community than a true individual. Our brain does a pretty good job of controlling our muscular system and rational thought, but most bodily functions and regulations are inaccessible to us. Not only can’t we do anything about most of them, we can’t even get information on them without inventing machines that can tell us. And to get back to pain, while pain can be useful, it can also be counterproductive. When nerves start firing, wouldn’t it be useful for you to be able to tell them, “Okay, I get it, I’m on fire, now let me figure out how to make myself not be on fire rather than filling my brain with nothing but pain signals.”
Now assuming millions of years of natural evolution, would we expect to see some of these things get better? Or are there limitations to the process that make certain things impossible unless a higher intelligence like man intervenes?
None of those examples you gave interfere with the sexual reproduction abilities of the people involved, nor do they kill off their children before they reach reproduction age.
So evolution doesn’t care about those minor items.
There are no advantages to more sophisticated brain-body coordination? Now the fat example I can see, since being overweight is unlikely to kill you before you have a chance to reproduce, but the ability to handle pain more intelligently or to regulate bodily functions more directly if necessary seems like a very useful thing for survival, in much the same way intelligence gave humans a big advantage.
Evolution has no intelligence. Survival is not correlated with breeding prospects, on the whole, in modern life since almost everyone survives to breeding age. Even people who would, by nature, die in the womb are now able to live long and reproductively-complete lives.
Probably the major factor on human evolution, at the moment, is that people who are more poorly educated and who have worse prospects in life are having more children than those who have a better education and better prospects in life. Assuming that meritocracy is involved in that distinction to at least some extent, people who are less likely to do well in life are - from an evolutionary standpoint - finding the current environment to be more suitable to their reproductive success than people who are likely to do well in all other respects.
The only other factor I can think of is how often a person spends their time drunk during their teen years. That is going to be strongly correlated to dying an early death. People who are more “social animals” or natural drunks are being selected against, perhaps.
Evolution: very slow
Human societal and technological change: very fast
If you could visit the year 2500 I’m sure that humans will have a lot of physiological and even psychological differences from you and I. But they’ll be because of environmental differences, improved medical knowledge and surgery, cybernetic implants / augmented reality, genetic engineering and so on.
Not because of survival of the fittest.
Selection doesn’t have to be boolean kill/survive- it can operate at a statistical advantage/disadvantage level and still drive evolution in a population - for example, for a trait to decline in a population, it doesn’t need to kill babies - it only needs to reduce the average capacity for having surviving children by a percentage (rather than an increase in infant mortality, which would be more conspicuous)
The purpose of pain is to tell you “whatever you are doing, stop it, now!”, or If you start having pain as soon as you have cancer, what are you going to do about it? For the vast majority of the time complex animals have been on Earth, you get cancer, you die. (The only change has been recently for some humans who have access to extraordinary means and some of their favorite pets–for most animals it remains that way.) If anything, the flaw isn’t that cancer doesn’t hurt sooner, it is that cancer ever hurts at all.
It would be nice to have pain that continues only to the point that you can do something about it (stop holding that cactus, shake that angry bandicoot off your ankle) then stop hurting when the danger passes, but 1.) evolution can’t “look ahead” and plan solutions, and 2.) “comfort” is arguably not a barrier to reproduction (“not tonight, I have a headache” being a notable exception.)
This one has the potential to be modified by evolution, but only if humans became unwilling to have sex/children with people who are fat. But that doesn’t seem to be happening. (While some fat people may have problems getting sex, those that do may end up having a boatload of children (citation: American reality TV.))
As in point 1, any information you would receive on internal problems would be evolutionary pointless because there is nothing that you can do about it (without modern medical technology.) What would be the point of your body telling you “hey just so you know, your pancreas just died” when there is nothing that you can do to run away from or fight off a dead pancreas?
As for conscious coordination, do you really want to have to remember to digest your food or filter out your urine? With semi-voluntary systems such as blinking or breathing, under stressful moments or times of high concentration, you can temporarily “forget” to blink or breathe. Would you like to be concentrating on something and forget to beat your heart?
As is common, many people talk about the evolutionary process incorrectly. Only one person here so far, seems to get the jist of it.
The main thing to watch out for, often made worse by careless educators, is the use of phrasing that makes it sound as though evolution is some sort of giant FORCE or ENTITY that makes MINDFUL CHOICES, on the grounds that it “makes sense.”
If you think about it from a slightly different point of view, something that you can gain great insight about it from, is by recognizing that the only reason why evolutionary change happens at all, IS BECAUSE OF HOW SLOPPY THE REPRODUCTIVE MECHANISMS ACTUALLY ARE.
If the way that a given entity reproduced was perfect, no accidental changes would occur. No mutations. And therefore no chance for some entities to be able to survive to reproduce again, when some disaster happens. Therefore zero change in the entity at all.
Dispute the ‘only if’ clause here. There are myriad ways in which this (obesity/fat storage) could provide something for evolution to select - for example, if it adversely affected parenting capability, or (through impacts arising from early mortality of the parent) if it affects the reproductive chances of the offspring, etc.
It doesn’t have to do any of that in 100% of cases - it just has to exert statistical pressure.
The title to the thread asked "Are there certain problems with our bodies that evolution will solve? "
The answer is yes. Evolution will select against some things that are a problem at that time or select some trait that is advantageous at that time. (Solve is perhaps a poor word however.)
Do we know what they are?
No. Not a clue. What mutations might exist in the future is unknown, and how they relate to the conditions at that time is also unknown. Pressures on features of the existing diversity of humans is also impossible to predict in the future.
Kurt Vonnegut’s Galápagos has a particular take on what traits might be selected for as time passes to ensure the survival of the species.
Seeing as alcohol reduces sexual inhibitions, and we’re making abortion more and more inaccessible, I’d argue that natural drunks are being selected for.
What mutations may occur is an unknown, and so is the human response to them. Our pattern is to intervene and stop people from dying of mutations that we can fix or compensate for, allowing them to survive to reproductive age, and treat the infertile so that they can reproduce, as well as caring for the babies of those who die, even if they’re not in our personal genetic line. So it’s quite possible that human evolution will take us not in what we perceive to be a more positive direction, but a sicker, weaker one.
Evolution doesn’t “care” about fit and healthy in a medical sense. A sick person in a high technology environment that allows them to reproduce is just as “fit”, in an evolutionary sense, as a healthier one.
I should have said, "Would evolution solve these problems if we were not interfering in the process?
It does seem that some evolution is pretty predictable. For example, whatever senses a species needs most will become highly developed, while senses they need less will tend to stay primitive.
Another point is that your examples 1 and 3 are common to all vertebrates. That’s a common misconception when thinking about evolution, that human organs/systems are somehow “special” when the majority of them are not. Creationists (not accusing you of being one) will talk about the impossibility of the evolution of the human eye, but neglect to mention (or possibly even realize) that the human eye isn’t all that different from the cow eye, the rabbit eye, the turtle eye, and the catfish eye (to name a but a few.) If 1 and 3 are problems that need to be solved by evolution, why assume that it will be humans that evolution solves it for, instead of cows, rabbits, turtles, or catfish? Why wouldn’t it have been solved 400 million years ago with the first tetrapods and thus been inherited by everything that descended from them?
(While numbers 1 and 3 are pretty universal issues, number 2 varies from animal group to animal group, with some having more potential for fat storage than others. You won’t find many fat animals in the wild, but pampered, overfed pets can and do happen.)
This. The only way evolution can select for/against any given trait is if that trait makes you more/less likely to survive to the age of reproduction and have viable children.
Let’s consider the OP’s examples:
Stubbed toes used to be extremely dangerous. If a real foot injury kept you from hunting and gathering, you starved to death, so the pain signal for a stubbed toe needed to be industrial strength so as you remind you “hey dipshit, be more careful with your feet, or you might die.”
Is there a chance evolution in the future might select for people who feel less pain when they stub their toes? Probably the opposite; even in the modern day, someone who keeps smacking and cutting their feet is more likely to get a potentially fatal infection. I suspect evolution will continue to select for a strong pain response; pain is good for you far more often than it is bad for you. On those rare occasions that it is bad or just annoying, technology has the answer in analgesics and anesthetics.
Lack of pain is more dangerous, as you’ve suggested. Example, people with esophageal or pancreatic cancer often don’t notice any symptoms until they’re at or near the terminal stage of the disease. 10,000 years ago it didn’t matter whether it hurt or not: if you got cancer, you were screwed. Now that we can do something about it, maybe evolution will select for a pain response that sends you to the doctor soon enough for successful treatment. But it’s likely to be a very weak selective pressure, since situations like this are pretty rare, and when they do occur, it’s usually later in life, after the individual has borne children.
Same deal, obese individuals rarely die (because of their obesity) before they’re old enough to have kids. No reason to expect any selective pressure in the future. In fact, quite the opposite: to the extent that there’s any genetic propensity for a given individual to develop morbid obesity, modern medicine/society is doing better at ensuring these individuals get treatment and survive to reproduce. If anything, evolution is now relaxing the genetic requirements for survival.
When time is of the essence (e.g. fire, tiger attack), the pain and fear responses give a survival result far more often than any rational response, so evolution will select for pain/fear instead of against them. This won’t change in the future.
And as long as modern medicine can tell us important things about our body, there won’t be any evolutionary selection pressure for us to develop innate sensing abilities. Take hypertension, unsensed by your unaided body, but easily measured (and treated) with technology. There’s no reason to expect that evolution would select for the ability to directly detect hypertension in our own bodies, since hypertension is rarely a problem before you’ve made/raised babies. This is true for a whole lot of medical conditions.
Oh, that much I knew. It almost seems like our advanced brains were just patched onto an ape body, then they threw in an opposable thumb and called it a day. You would think that an advanced brain would also have more advanced functions for regulating automatic processes yet it seems that some animals are actually more sophisticated than us in this regard. For example, I’ve read that rats’ hearts restart. I guess sometimes human hearts can restart, but usually it takes intervention to make that happen.
Now the eye, that brings me to another question. How DOES an eye evolve? An eye is very sophisticated, yet it has really only one purpose: to enable one to see. And until one can see, it’s not doing anything to aid in survival. So how does that mutation happen? Did a fish just get born with a simple eye one day 4 billion years ago?
Proto-eyes are very useful, and found throughout the tree of life. Plenty of single celled critters have eye spots, that simply measure the amount of light. Those can be coupled to locomotion mechanisms to move the critter to an environment with the right amount of light. Need to photosynthesize but you’re in the dark? Start moving in a straight line, if the light gets stronger keep going, else turn around and try again.
Between simple eye spots and our image-forming eyes, there are plenty of useful intermediates. If you block light on one side of an eye spot, you now have a directional way to measure light. Put several eye spots in a pit, and you can measure the light in several directions at once. Cover that pit with a small opening and now you have a pinhole lens that can form an image. Cover the opening with a clear substance and light sensing cells are protected. Change the shape of the clear covering and now the image is clearer. Etc…
Oh, I didn’t know eyes developed so early. So although the human eye is very complex, it is possible to see out of something much simpler? That’s pretty cool.
It didn’t happen just once. It’s happened, as best as we can tell, some 50 or more different times.
The general pattern seems to be that a Thing mutates some area of a cell or cells so that they can sense light. This is usually a good thing, and that Thing has better opportunities to feed and to avoid predators, and so it makes more babies than other Things. (These Things are often unicellular, so the beginning of the evolution of the eye goes waaaaay back.)
Eventually, one of the Thing’s descendants, now multicellular, has a mutation that forms a depression in a group of cells that can sense light. This is way cool, because now the Thing can tell which direction light is coming from. Even better for finding food, avoiding prey, and finding mating partners. More babies with light sensors with depressions are made and survive than babies without the depression in their light sensors.
The next mutation is a constriction of this depression, which aims light waves better, and allows the Thing to see light, direction, and some rudimentary shapes of items in the environment.
Another mutation may provide a layer of transparent cells over this eye, protecting it from injury and infection. Fluid forms between the transparent layer and the light/direction/shape sensing area, and this allows the Thing to leave the water and see on land. It also, in some Things, allowed for the first differentiation of color.
Sometimes a mutation happens that causes a group of cells to line up in a vertical fold. Those are eyes with lenses, that allow for greater focus. Sometimes these lines mutate and split, forming a cornea.
And so on.
Far from the Creationist argument that an eye isn’t useful unless all the components are in place at once (and how unlikely would it be for a Thing to mutate all these mutations at once? Very.) the eye is a whole bunch of different mutations that each gave Things better evolutionary fitness in their environment.
