[ home / bans / all ] [ qa / jp ] [ spg ] [ f / ec ] [ b / poll ] [ tv / bann ] [ toggle-new / tab ]

/spg/ - Spring

Seasonal board for the Spring Season

New Reply

Options
Comment
File
Whitelist Token
Spoiler
Password (For file deletion.)
Markup tags exist for bold, itallics, header, spoiler etc. as listed in " [options] > View Formatting "


[Return] [Bottom] [Catalog]

File:MarchofProgressPanels-1ou5….png (1.66 MB,2369x1586)

 No.2998

Every now and then people like to talk about future human evolution, that humans hundreds of thousands and millions of years from now humanity may be a completely new species that does not resemble a modern human any longer. Do you think so?

Personally, I'm inclined to believe that evolution is like language. When there is a strong social fabric connecting one person and community to the next, languages evolve very slowly. When that cohesion breaks down, languages tend to diverge and evolve. I think evolution is probably something like that, and within our broader interconnected world, humanity will probably evolve more slowly together and so maybe that human born hundreds of thousands and millions of years from now will resemble us much more than others like to suggest.

 No.2999

I don't think there is much of an evolutionary pressure for humans to evolve anymore given that we are so dominant and that we have the ability to shape the world into doing what we want it too. Technology is our evolution in a way.

So I think it's possible that we won't ever change, not to any serious degree anyway.

 No.3000

File:noo.jpg (48.29 KB,848x480)

>>2998
>>2999
I'd like for humans to increase their average lifespan while retaining their youthful looks and agility in the distant future.
>Technology is our evolution in a way.
I wonder if our average lifespan increasing can be considered evolution, isn't that a product of technology too? I don't remember how it works.

 No.3001

>>3000
>I wonder if our average lifespan increasing can be considered evolution, isn't that a product of technology too?
Yes, basically you can think of it like this. We have the ability to cure and prevent many illnesses, diseases and such as well as the ability to prolong the life of people afflicted by the things we cannot cure. That's what raised our average life spans, that and a reduction in infant morality. Some people in the past did live long lives but that was because they were lucky and never were affected by any of these things, it's kind of like playing Russian roulette every year but instead of a bullet it's a now curable illness, chances are you will eventually get hit by one but not everybody will.

 No.3002

>>2998
>Personally, I'm inclined to believe that evolution is like language. When there is a strong social fabric connecting one person and community to the next, languages evolve very slowly.
In a way, this is not incorrect, but for a different reason.
When there are no strong evolutionary pressures, evolution will generally only subtly diversify in the background. When you have a strong social fabric, that implies that you have a stable society, in other words, there probably is not a lot of strong evolutionary pressure.

However, as soon as the species (or a subdivision thereof) has to pass through a bottleneck, you will find that the aforementioned diversification will crystalize into a distinctly new shape - one that is adapt at dealing with this challenge.

 No.3003

>>3000
>>3001
From what I understand, humans living longer is basically all environmental. There's very little actually pushing humans to live longer evolutionarily because people generally have children while they're young, so selection pressure only ensures that people live up to that point. This is more or less why so many diseases only show up very late in life; there's no evolutionary advantage to someone being resistant to dementia or heart disease if those disease don't occur for 40-50 years after someone has already had children. Maybe various fertility treatments that allow people to have children when they're older will start pushing up lifespans.

 No.3004

>>3003
>There's very little actually pushing humans to live longer evolutionarily because people generally have children while they're young,
While the latter is correct, the former is not.
If you die 5 years after having produced offspring, you will have left your offspring completely unprepared for life, and thus you have not ensured the survival of your genes.
Humans are a rare species where long-term parental care is clearly strongly selected for. Our young are almost uniquely helpless.
But with that biological fact, there sneakily comes along a second fact, which is cultural. One of the most important ways in which we can expand our knowledge and share it with others is by living past the age of reproduction.
No matter how much the average 20 year old thinks they've got it all figured out, everybody knows that the actual experts on any given field are probably 40+ years old. This is true in this extremely advanced civilization, but it was true thousands of years ago too.
(that said, the evolutionary pressure for a life into the 60s is of course much weaker than the one for a life up to at least an age of 15)
>Maybe various fertility treatments that allow people to have children when they're older will start pushing up lifespans.
There are a variety of factors that influence the ideal life expectancy. Food availability, cost of raising offspring, cost of raising high-quality offspring...
Life security is a big one too. There is no point in having a theoretical life expectancy of 1000 if you are living in an environment where you can expect to be murdered before you reach the age of 30. If enhancing your overall life expectancy has negative effects on any of the short-term priorities, your current DNA is already prepared to adapt its strategy. There are a few points during development where your body takes stock of the situation and "chooses" the appropriate strategy.
Organisms that find little food for example grow less big. Not because they can't grow bigger, but because there is an implicit low confidence in their ability to stay healthy at a larger size.

 No.3005

>>3004
>There are a variety of factors that influence the ideal life expectancy. Food availability, cost of raising offspring, cost of raising high-quality offspring...
These are all environmental factors... You can say that those things do have an effect on lifespan, and they do, but they have nothing to do with the innate biological ability to live a certain amount of time. You can pour thousands of dollars into a fishtank, but the presence of money itself will not make the fish live any longer. What you're describing is epigenetic gene expression, not evolutionary pressure to live longer or shorter lifespans.

 No.3006

>>3003
To a degree, but a lot of the things that used to kill people back in the day were also killing children and those of breeding age. So there probably isn't much of an evolutionary pressure to select for those resistant to heart disease but there would be for those resistant to tuberculosis.

 No.3007

>>3005
>These are all environmental factors...
I did not say that they weren't.
>they have nothing to do with the innate biological ability to live a certain amount of time.
They do, because "the innate biological ability" that you speak of depends on what exactly that life form is "attempting" to do, and not a fixed thing.
>You can pour thousands of dollars into a fishtank,
I am not sure what you are trying to accomplish, using money instead of the nourishment. When I spoke of "cost", I was not referring to a modern abstract idea of money, but simply resources.

 No.3008

>>2999
Evolution just describes the phenomenon of populations becoming genetically distinct from their originating population. Unless we start sustaining the species through cloning alone, the processes driving evolution will continue to occur. OP is surprisingly correct insofar as the larger a population (meaning a group of individuals who breed with one another) becomes the more slowly it diverges because random mutations take longer to propagate. Evolutionary pressures speed up the process by killing off the individuals without certain traits, but any populations that are reproductively isolated will begin to diverge from one another and, considering we'll all be dead by then, nobody in 1002024 is going to be reproducing with us.

Also, even if traits aren't being culled by the environment killing them off, the traits that incline men to ignored 3DPD for anime girls or that make women wait until they're practically infertile to attempt reproduction will still get filtered out over time. It's a more subtle thing and its hard to say whether enough of that is genetic for it to actually kill off traits, but as long as some people are reproducing more than others the gene pool will continue to shift in their favor.

>>3000
>I wonder if our average lifespan increasing can be considered evolution
No. Average lifespan statistics from pre-modern times are immensely skewed by high infant mortality. People who made it past 5 and didn't engage in especially adventurous lifestyles (you'd be resistant to local diseases and conditions from childhood exposure, but less so the farther away you went) were likely to survive to old age the same as we do. It is entirely due to better medical care that people are able to survive the naturally vulnerable parts of their lives better. A few generations is not nearly enough for new traits to spread across the majority of humanity. The same goes with how people are significantly taller now than in the past, at least in places where children get plenty of nutrition.

>>3004
While it is certainly beneficial to have both parents around to raise their kids, it's far from necessary. Humans have always lived in communities and offloaded some of the burden of child rearing on that community, it takes a village and all. It's not like the experts need to be your dad for you to benefit from them. The bigger problem with dying when you're 40, especially for men, is that you lose out on additional kids you could have had.

 No.3009

>>3008
>Humans have always lived in communities and offloaded some of the burden of child rearing on that community
You forget that in order for these people (mostly your relatives plus a few traded spouses) to live long enough to take over for you, they also need the genetic makeup that would extend their lives into that age range.

 No.3010

>>3009
Even if we're going way back to pre-neolithic tribes without things like orphanages and assume that both parents die together with no potential for remarriage, you would still have community members younger than you who are still capable of raising children unless your whole family has a hereditory condition that makes them die by their late teens. If you have kids at 70, you can just die and let your adult children deal with their new sibling. If you die at 25, have your 20 year old nephew take over and so on. It's only a problem when resource constrictions force them to choose between your kids and their own that having other people raise your children becomes a potential issue.

 No.3011

>>3010
I believe we are talking past each other.

I am saying that the genetic trait of longevity need not reside in the individual but in the group in response to an anon arguing that there is no biological reason for humans to live past their child-birthing age (teens).
You are disagreeing with me on the grounds that you assume that this longevity that I am arguing for is already present in the community.

 No.3012

>>3011
I believe the original point was that there was little impetus to live past reproductive age, which in this context means any age at which one can reproduce. A woman being able to survive past her first birthing is obviously beneficial, but her being able to survive past menopause has little impact on the survival of her genes. That's why traits that kill people in their teens die out while traits that kill people in old age persist.

 No.3013

>>3011
>an anon arguing that there is no biological reason for humans to live past their child-birthing age
That was not what I was saying. I was saying that evolution is most biased by the time up to the point it takes to produce children, and that beyond that point there is negligible selection pressure for evolution to increase lifespan (or for there to be almost any evolutionary pressure at all). Huntington's Disease is near-proof to confirm this; individuals are unaffected through to mid-adulthood but from around 30-50, symptoms begin presenting and the they begin experiencing neurological decline. Were it the case that there were evidence of evolutionary pressure PAST the point of childbirth, there would likely not be inheritable genetic diseases such as Huntington's Disease.

 No.3024

File:[AonE]_Hidamari_Sketch_x_S….jpg (254.02 KB,1280x720)

How come we haven't evolved out of needing sleep?

 No.3025

>>3024
i'm not sure the reasons behind the evolution of sleep are entirely clear but it's widely agreed it's pretty important stuff

 No.3026

>>3024
From what I understand, sleep serves a few functions, that we know of. First is detoxification. While you're awake, toxins build up in the brain, and restful sleep allows the body to detoxify the brain. The second is memory consolation. It seems that during sleep our brains essentially go through a categorization process where things that happened during the day that were in your "medium-length" memory get turned into long-term memories. Third is healing. Wheen you sleep your body releases hormones that allows for you to heal.

I'm pretty sure those are the main reasons. I'm just a layman though.

 No.3027

>>3025
>>3026
There is also a more indirect reason for sleep: Nights.
It's just energy-efficient to go into a energy-saving mode in a time when it's cold and dark and it's difficult to spot the resources you want, or avoid the predators to whom you are the resource.

 No.3033

>>3024
Because there has never been a random mutation in our evolutionary line that allowed someone to survive without sleep, or if there were that person was unable to pass those mutations on long-term.




[Return] [Top] [Catalog] [Post a Reply]
Delete Post [ ]

[ home / bans / all ] [ qa / jp ] [ spg ] [ f / ec ] [ b / poll ] [ tv / bann ] [ toggle-new / tab ]