> One day, scientists might be able to successfully mimic the expansion of the interstitial space that does the mental janitorial work so that we can achieve maximally efficient round-the-clock brain trash pickup.
We can ask the same question the article poses initially about why we still sleep. Why hasn't this evolved yet? What are the disadvantages of this 'always-GCing' approach? In a best-case scenario, it might just be some sort of historical limitation that no longer applies* (just as our tendency to get fat is a result of an approach to resource conservation that made sense in the ancestral environment, where food was scarce and opportunities to feed intermittent, but does not in modern civilization, where food is nearly always available). In a less appealing scenario there might be some tradeoff that causes us to think less efficiently when this interstitial space expands.
[*] The extra fluids have to come from somewhere, which would mean they're not available for other tasks. Similarly, digestion is expensive--blood flows to the intestines after a meal, and if this is to happen then (since in the short term, you have a fixed amount of blood) it's less available for fueling your muscles. (And if you force yourself to be active right after a meal there's contention for these finite resources. Ever go for a run right after eating?)
Though perhaps there's less fluid involved here than there is with the intestines.
Evolution is actually quite horrible at engineering. Since it can only hill-climb, we end up with ridiculous designs stuck in local maxima. Evolution made video cameras out of jelly, a breathing tube that must be crammed full of solid foods every few hours, and (as Neil deGrasse Tyson put so delicately) a sewage plant next to an amusement park. No organism ever evolved radio communication, or the ability to transmit nerve signals faster than 0.000001c.
Still, why 8 hours of sleep instead of 2? The best explanation I've heard is famine resistance. Sleep conserves energy; until recently, humans were calorie-limited. Also, there's probably an advantage to remaining quiet and still in the dark, when human eyesight is at its worst and predators roam.
Forcing a requirement to think about providing a safe place to sleep results in at least some thinking about safe places to be awake in, and think about defenseless youth in general. If you have to think about finding a safe place to sleep every day, occasionally thinking about a safe place to give birth shouldn't be as challenging. Sounds convenient for long life and successful reproduction.
Also you can tell who hasn't had kids... without kids sleeping (and sleeping more than the parents) the older adults and teens in the tribe would go bonkers and be unable to accomplish anything. Best thing that ever happened to a newborn was sleeping alot so mom can get some food in her, etc. I guess as you get older you could ramp it down and maybe teens could simply stop sleeping, this is probably a secondary effect at most.
Why take human engineering out of 'evolution'? Biological evolution developed our brain and manipulative appendages, which were then used to make better video, comms, etc.
Humans, and everything we do, are still 'naturally evolved', by definition.
Side note: according to some sleuthing by the snopes crowd[1], this quote predates Lincoln's presidency by several decades, with the first recorded usage being somewhere around 1834. He may have used the anecdote himself, but it seems to have been a popular saying in the abolitionist movement in general.
Mostly because... I have no idea why. I mean we've discovered something very close to spears being used by people since ... well forever in terms of modern history.
And hunting being very important to the needs of certain homo sapiens sapiens populations would very much agree with your assessment. One advantage that we hold over primates is our ability to throw. Combine that with making spears and our ancestors quickly becoming apex predators makes sense.
Your brain has 200 billion-ish neurons with hundreds of trillions of connections between them. Right now, reading these words, your visual cortex is doing edge detection and motion filtering. That requires FFTs and other complex computations.
Quick! What's 392 * 7374?
99.9% of people on the planet need pen and paper to figure out the answer. Our oh-so-adaptable brains can't seem to make a few neurons available for simple math. Heck, our brains can't store more than 7-9 items in working memory.
We're mostly unaware of our limitations because everyone else is similarly hobbled. But when we figure out a way to improve human minds, it will be a bigger game changer than anything that has come before.
I was responding to "Evolution is actually quite horrible at engineering. Since it can only hill-climb, we end up with ridiculous designs stuck in local maxima". In my opinion, several qualities of natural life compare favorably with man-made engineering (which is the only other type of engineering I can think of for the purpose of comparison), therefore I disagree that "evolution is actually quite horrible at engineering", at least without some kind of qualification.
I don't understand the purpose of your 1st or 4th paragraphs; I understand the 2nd and 3rd as saying something like "human brains are limited", but don't see how it connects to my response.
Could you clarify for me? Sorry that I didn't follow and thanks.
In fact you can pull up articles with a quick search about how people can attain pretty good mental math capabilities through training. It's hard work, but it's proof of the adaptability of the human mind.
I don't know I already thought the computer was the first "lever" for the mind that we've had. The computer has been pretty game changing for society, has it not?
I learned multiplication long before computers were commonplace, and when four-banger calculators were still quite expensive. The reason I can't do that calculation in my head (well, I could but it would be faster to grab a pen) is that I don't have enough stable registers. I'd guess maybe two registers that won't get corrupted during the calculation. They're not big registers, either.
Regardless, I'm not saying that there isn't a technique that would allow me to improve. I'm saying my inability has nothing to do with ubiquitous electronics.
> The reason why people can't do that calculation in their heads is because of our reliance on computers and calculators.
No, we were never well equipped to do such computations, we didn't suddenly get worse at it with the invention of calculators. Consciously aware mental calculation is a very recent thing on an evolutionary time scale. I think even 10-20k years ago no one did any mental calculations beyond the most trivial arithmetic operations.
OTOH we have a pretty cool native physics engine in our brains and can solve pretty challenging problems such as predicting trajectories and modeling fluid flow. These skills were much more useful in our evolutionary past than arithmetic or algebra.
I suggest that the tendency to get fat is protecting us as a species on an evolutionary scale.
It's unwise to believe we could ditch that just because we haven't needed it for the last 2 generations or so: evolution cares little about a 2 generations scale.
Nice job anthropomorphising evolution. Unfortunately that path leads to ruin.
Evolution has no foresight. Evolution can’t predict the future. Evolution is firmly rooted in the here and now. Doing something now (or not doing something now) because of a prediction of the future is something only humans can do, not evolution. Evolution knows no future.
Evolution knows no future, but it still makes sense to talk about evolution being prepared for a possible future. In particular, what ronaldx is saying is quite close to the accepted explanation for sexual reproduction. Sex produces, and maintains, a great deal of variety within the population that you won't see in an asexually reproducing one. It also imposes a very large penalty to the speed at which the population can grow (males, roughly half of any sexual population, cannot reproduce at all). It is felt that, historically, sexual populations have been so much more able to weather changing circumstances, because of the variability that their lifestyle ensures, that it must have outweighed the susbstantial reproductive penalty -- since sexual organisms have taken over virtually every ecological niche in the world. And this is for an adaptation the entire purpose of which is to guard the population against the future.
In summary: variability in the gene pool is a form of future protection, and one that has been specifically selected for. Be careful before you shout "fallacy!"
What I claim is that this iteration of humans have survived catastrophic black swan events in the past, and that catastrophic black swan events will happen in the future (in a very-long-term, i.e. evolutionary, timeframe).
Living humans don't have any reasonable concept of that, but evolution does have a memory of that[0].
I trust evolution to cover us for this type of future event better than I trust human prediction.
Being rooted in the here and now is something I would ascribe to humans before evolution: humans typically think as individuals on a time scale of 100 years - whereas if something has not been needed for 100 years, this does not illustrate that it is no longer of evolutionary importance.
[0] You can claim I am anthropomorphising here (but not in the earlier comment), but this is sometimes called an analogy, and is an accepted way of using the English language to describe concepts in a clear and simple way. Please ask any geneticist to translate this into evolutionary terminology if you remain unsure.
> […] why we still sleep. Why hasn't this evolved yet?
A number of animals can put one half of the brain to sleep while the other half remains alert¹.
As for eliminating sleep or shortening it; for such “trait” to evolve there would (beyond being physically possible and the proper mutations having occurred) need to be an advantage that would cause more individuals with the trait to survive (and pass on their genes).
Considering that we have been sleeping in trees and caves, and in groups, there’s probably not a significant larger chance of someone requiring less sleep to make it through the night.
alternatively, the genes that allow for this would just need to be the dominant ones, the recessive ones that we have now being just the result of a lot of bad luck.
Philosopher Nick Bostrom makes the same argument more generally and detailed here: www.nickbostrom.com/evolution.pdf
We shouldn't expect easy congitive enhancement through drugs unless there is a strong reason it wouldn't have been advantageous in the ancestral environment that doesn't matter now (e.g. much higher calorie usage).
I don't have the will to read a 40 page pdf at the moment, but my initial reaction to that argument is that evolution is not perfect and does not produce the same results in all species. Some animals hibernate for months, while some sleep much less time than we do. Not to mention that it seems like a cop out that avoids any possibility of progress through technology.
Why should we expect an easy cure to syphilis in a drug if evolution has not found one? I don't know, but penicillin still works pretty darn well.
In fact, you shouldn't have expected an easy cure to syphilis. It's a dramatic exception. The vast, vast majority of problems the body has are not easily solved by a simple chemical. This is born out by the tremendous difficulty of finding effective drugs which don't carry unacceptable side effects.
I suspect it's tied to metabolic limitations. It's likely difficult for the brain to provide enough energy to support higher order functions and also do this cleanup efficiently at the same time.
We can ask the same question the article poses initially about why we still sleep. Why hasn't this evolved yet? What are the disadvantages of this 'always-GCing' approach? In a best-case scenario, it might just be some sort of historical limitation that no longer applies* (just as our tendency to get fat is a result of an approach to resource conservation that made sense in the ancestral environment, where food was scarce and opportunities to feed intermittent, but does not in modern civilization, where food is nearly always available). In a less appealing scenario there might be some tradeoff that causes us to think less efficiently when this interstitial space expands.
[*] The extra fluids have to come from somewhere, which would mean they're not available for other tasks. Similarly, digestion is expensive--blood flows to the intestines after a meal, and if this is to happen then (since in the short term, you have a fixed amount of blood) it's less available for fueling your muscles. (And if you force yourself to be active right after a meal there's contention for these finite resources. Ever go for a run right after eating?)
Though perhaps there's less fluid involved here than there is with the intestines.