Can think of another factor...throughout history the kings/emperors/etc wanted obedient serfs/slaves. They may have tended to weed out the more aggressive/intelligent/ambitious type humans in favor of physically weaker more submissive to authority types. Masters don't want really smart slaves. They get too smart they might start questioning the self-serving things they are taught like that the rulers are "divine". Most people throughout history weren't generally allowed to carry arms, discouraged from even having an interest in such accept during times of great emergency. Perhaps the wars were some subconscious way rulers curbed the pop. of strong/aggressive young men whom they may have perceived as a treat to their rule. We were being bred to be "domesticated" and therefore easier to control.CaptainBeowulf wrote:The social welfare state may be an extreme example of it, but I think that most societies/civilizations - even ones in early transition from stone age to iron age - function to reduce selection pressure. Difficult to say with the ones that conduct organized mass murder - the mass murder is likely indiscriminate at a genetic level (discriminate on tribal, religious, class or ethnic/racial levels).
Many societies have religious codes which suggest that you should help the needy etc. These are not always followed, but still, things like alms houses go right back through the middle ages. More generally, societies provided organized hunting and farming opportunities, which provided a lot more food. Perhaps the strongest kept the best food for themselves, but weaker people who would not have survived in a very primitive state now got enough to get by and possibly reproduce once or twice.
Also, fortified towns, organized military forces, clearing of land etc. etc. greatly reduced the populations of other large predatory animals which compete with and occasionally predate humans. This again allowed many more people to survive.
Beyond this, when you look at the scale and destruction of classical era battles such as Cannae, you realize that many of the fittest young males may have been marched off to war and slaughtered generation after generation before they had had much opportunity to reproduce (zero to one or two children), thereby actually working counter to the way that natural selection would have worked in a pure hunter-gatherer society.
I have read that some biologists think that humans have evolved fair bit on the genetic level in the last 2000 years - basically in terms of immunity to diseases. Urban societies were breeding grounds for plagues, and it stands to reason that the main selection pressure before the advent of modern antibiotics was for resistance to various classes of virus and bacteria. It could be - I don't know if there's anything conclusive on this topic.
Human Evolution Isn't What It Used to Be
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CaptainBeowulf
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There was definitely some extermination of potential rivals - the following example is amusing after a fashion: Gregory of Tours recounts to us how Clovis, the first king of "France," (essentially the first Frankish king who successfully added most of Gaul to his domains), gave a speech towards the end of his reign about being a poor old man who was lonely and had no family members to comfort him. People joked that he was attempting to lure any surviving members of his family out of hiding, so that he could have them executed on trumped up charges, since he had already done so all the relatives he could find.
More generally, though, I think that humans tend to be politically pugnacious, and when things like nuclear weapons, thermobaric bombs, and a few major powers with aircraft with PGMs didn't exist, it was much easier for rulers and elites to think that they might profit by going on military adventures. Fit young males were the best at holding heavy shields and wielding heavy weapons, so they got used as soldiers... I doubt it goes beyond that.
I would agree, however, that humans have "self-domesticated" in another way. For the past few thousands years organized societies have set up legal systems to stop people from using violence and fraud on each other, and the state has asserted a monopoly on violence. This is more or less necessary to prevent chaos when you have a lot of people jammed together. However, it has also typically extended to enforcing social mores of one kind or another, and of course, for centuries it did execute people who were found to have committed treason or acts like "lese majeste" against a monarch.
This generally removed those with more "wild" instincts or behaviors from society, and may have functioned for long enough now to result in a somewhat more passive population. However, this would not necessarily correlate with intelligence, it would correlate with a selection pressure in favour of those with better self control over their violent impulses.
Experiments with domesticating foxes in Russia, combined with observable differences between wolves and dogs, wild cats and domestic cats, aurochs/wild cattle and domestic cattle, etc., etc., seem to suggest that a less violent temperament is achieved by breeding animals so that traits only found in the young also appear in adults. Also, these domesticated species are often less intelligent than their wild counterparts. However, it's by no means certain that the same effect could have happened with humans. Greater self control and avoidance of violence in humans may actually be an aspect of greater intelligence, not of a lessening of intelligence through "domestication."
More generally, though, I think that humans tend to be politically pugnacious, and when things like nuclear weapons, thermobaric bombs, and a few major powers with aircraft with PGMs didn't exist, it was much easier for rulers and elites to think that they might profit by going on military adventures. Fit young males were the best at holding heavy shields and wielding heavy weapons, so they got used as soldiers... I doubt it goes beyond that.
I would agree, however, that humans have "self-domesticated" in another way. For the past few thousands years organized societies have set up legal systems to stop people from using violence and fraud on each other, and the state has asserted a monopoly on violence. This is more or less necessary to prevent chaos when you have a lot of people jammed together. However, it has also typically extended to enforcing social mores of one kind or another, and of course, for centuries it did execute people who were found to have committed treason or acts like "lese majeste" against a monarch.
This generally removed those with more "wild" instincts or behaviors from society, and may have functioned for long enough now to result in a somewhat more passive population. However, this would not necessarily correlate with intelligence, it would correlate with a selection pressure in favour of those with better self control over their violent impulses.
Experiments with domesticating foxes in Russia, combined with observable differences between wolves and dogs, wild cats and domestic cats, aurochs/wild cattle and domestic cattle, etc., etc., seem to suggest that a less violent temperament is achieved by breeding animals so that traits only found in the young also appear in adults. Also, these domesticated species are often less intelligent than their wild counterparts. However, it's by no means certain that the same effect could have happened with humans. Greater self control and avoidance of violence in humans may actually be an aspect of greater intelligence, not of a lessening of intelligence through "domestication."
CaptainBeowulf wrote:This generally removed those with more "wild" instincts or behaviors from society, and may have functioned for long enough now to result in a somewhat more passive population. However, this would not necessarily correlate with intelligence, it would correlate with a selection pressure in favour of those with better self control over their violent impulses.
Experiments with domesticating foxes in Russia, combined with observable differences between wolves and dogs, wild cats and domestic cats, aurochs/wild cattle and domestic cattle, etc., etc., seem to suggest that a less violent temperament is achieved by breeding animals so that traits only found in the young also appear in adults. Also, these domesticated species are often less intelligent than their wild counterparts. However, it's by no means certain that the same effect could have happened with humans. Greater self control and avoidance of violence in humans may actually be an aspect of greater intelligence, not of a lessening of intelligence through "domestication."
Your ideas are somewhat reassuring accept for those points in bold. Hard to equate more or even equal intelligence with a "shrunk" brain. The poorer diet of the agrarian peasant throughout history probably didn't help much either (lower calorie cereal/gruel as opposed to the high protein/calorie meat the cro-magnon got.) I am guessing that it is probably a good thing if we get to the point we can genetically engineer for intelligence (and what the heck maybe a Cro-Magnon type physique..at least for the men don't know what the cro girls looked like) in the not to distant future. And having a new frontier in space in generations to come will be a good thing to, for a variety of reasons.williatw wrote:.First, it's clear, from glancing around society, that clever people—who on average have slightly bigger brains—aren't having more babies than less-clever people. Second, the fossil record strongly suggests that our brain size peaked at 1,500 cubic centimeters around 20,000 years ago and has since shrunk to 1,350 cc
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CaptainBeowulf
- Posts: 498
- Joined: Sat Nov 07, 2009 12:35 am
Well, there's what Skipjack pointed out:
Worth noting that Neanderthals were around 1500cc as an average too, so both they and the Cro-Magnons had around the same slightly larger average size as compared to the current population. The Neanderthals had a different braincase shape, which seems to have meant smaller frontal lobes and larger occipital lobes. What this meant for cognition is uncertain, except that perhaps their ability for abstract thought was more limited, as that seems centered in the frontal area. Whatever the case, the Cromagnons outcompeted them with a minimal amount of interbreeding (modern non-sub-saharan humans apparently having around 4% neanderthal DNA, and people with completely sub-saharan ancestry appearing to have none).
So, yeah, the shrinkage in brain size could represent a reduction in intelligence as a result of the historic conditions we've discussed above, but there's not enough evidence currently to say either way.
This is fairly well known, and not particularly controversial. It's possible that those larger 1500cc brains weren't as well organized; soft tissues like the cortex don't really fossilize, although on occasion they do leave surface imprints, so our information is very limited.It is amount of surface area of the brain that makes much of a difference. Also the way the different areas of the brain are connected.
Worth noting that Neanderthals were around 1500cc as an average too, so both they and the Cro-Magnons had around the same slightly larger average size as compared to the current population. The Neanderthals had a different braincase shape, which seems to have meant smaller frontal lobes and larger occipital lobes. What this meant for cognition is uncertain, except that perhaps their ability for abstract thought was more limited, as that seems centered in the frontal area. Whatever the case, the Cromagnons outcompeted them with a minimal amount of interbreeding (modern non-sub-saharan humans apparently having around 4% neanderthal DNA, and people with completely sub-saharan ancestry appearing to have none).
So, yeah, the shrinkage in brain size could represent a reduction in intelligence as a result of the historic conditions we've discussed above, but there's not enough evidence currently to say either way.
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palladin9479
- Posts: 388
- Joined: Mon Jan 31, 2011 5:22 am
What lots of people are forgetting is that child survival rate is more important then birthrate. Having ten children does no good if you can only feed three of them. This is what kept everything in check, if the parents were not strong / smart enough to somehow profit from their situation in life, then the number of healthy strong children they had that would survive to maturity would be limited.
Modern medicine coupled with social welfare programs has enabled the dumbest of the dumb to have ten children and have them all survive to maturity and have even more children. This ends up polluting the gene-pool to the extreme. Eventually it'll correct itself, but the longer that takes the uglier it is.
Modern medicine coupled with social welfare programs has enabled the dumbest of the dumb to have ten children and have them all survive to maturity and have even more children. This ends up polluting the gene-pool to the extreme. Eventually it'll correct itself, but the longer that takes the uglier it is.
It is pretty easy to confuse social status and intelligence. Personally, I am not convinced that "rich" college educated people are necessarily more innately intelligent than those who are not. Wealth and education causing people to have fewer children probably doesn't have that much effect because (1) the disparity in innate intelligence is not as great as imagined and (2) the disparity between rich and poor birthrates isn't as wide as is being depicted - at least in wealthier countries.
Lots of children being born in poor countries doesn't have an effect either. People are poor and uneducated in those countries because the country is poor, not because they are dumb.
Evolution of intelligence probably ended once we got intelligent enough that getting more intelligent didn't matter any more. Say when the Neanderthals were wiped out.
Lots of children being born in poor countries doesn't have an effect either. People are poor and uneducated in those countries because the country is poor, not because they are dumb.
Evolution of intelligence probably ended once we got intelligent enough that getting more intelligent didn't matter any more. Say when the Neanderthals were wiped out.
Stick the thing in a tub of water! Sheesh!
It's an odd thing to say on a forum such as this that intelligence doesn't matter any more. Certainly it is requisite in many jobs. The issue is how do you get a critical population mass located in the same area so that intelligence traits are selected for and not diluted by the general population. Consider Silicon Valley for example:seedload wrote:Evolution of intelligence probably ended once we got intelligent enough that getting more intelligent didn't matter any more. Say when the Neanderthals were wiped out.
http://www.nature.com/news/2011/111102/ ... 9025a.html
http://spectrum.ieee.org/biomedical/eth ... es-collide
http://www.wired.com/wired/archive/9.12 ... rs_pr.html
And then again maybe not:Evolution of intelligence probably ended once we got intelligent enough that getting more intelligent didn't matter any more. Say when the Neanderthals were wiped out.
http://www.jerrypournelle.com/reports/c ... cking.html
Engineering is the art of making what you want from what you can get at a profit.
I didn't say that intelligence doesn't matter. Of course it matters in a lot of things. I am just saying it stopped mattering to evolution a long time ago. In evolutionary terms all that matters is that you have children and they live to have their own children. In parents breed despite their intelligence and children live despite their parents intelligence, then it isn't being selected for. I think that happened a pretty long time ago.Netmaker wrote:It's an odd thing to say on a forum such as this that intelligence doesn't matter any more.seedload wrote:Evolution of intelligence probably ended once we got intelligent enough that getting more intelligent didn't matter any more. Say when the Neanderthals were wiped out.
Regardless, if anything modern is hampering the evolution of intelligence, it isn't how many babies dumb people are having, it's a lack of stressed and isolated human populations.
Regards
Stick the thing in a tub of water! Sheesh!
http://www.jerrypournelle.com/reports/c ... cking.htmlRegardless, if anything modern is hampering the evolution of intelligence, it isn't how many babies dumb people are having, it's a lack of stressed and isolated human populations.
Engineering is the art of making what you want from what you can get at a profit.
I've sometimes thought that human evolution, including the division into geographically localized races, has been guided more by optimal protection against disease.
If you look at the globe, you have 3 or 4 races largely concentrated on separate continents, with a small degree of intermingling.
Each race is both more vulnerable to and better protected against a different set of pathogens.
A new disease may take down the population of one of the races, but have little effect on the others. Eventually the decimated race recovers, think of the N.A. indians.
The small degree of intermingling allows immunity to be transferred from one race to the other.
If you look at the globe, you have 3 or 4 races largely concentrated on separate continents, with a small degree of intermingling.
Each race is both more vulnerable to and better protected against a different set of pathogens.
A new disease may take down the population of one of the races, but have little effect on the others. Eventually the decimated race recovers, think of the N.A. indians.
The small degree of intermingling allows immunity to be transferred from one race to the other.
CHoff