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Old 02-27-2017, 09:09 AM
Machine Elf Machine Elf is offline
Join Date: Feb 2007
Location: Challenger Deep
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Originally Posted by View Post

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.
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:

Originally Posted by adaher
1) 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.
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.

Originally Posted by adaher
2) 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
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.

Originally Posted by adaher
3) 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."
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.