Human civilizations before the last ice-age?

Factual Questions
81

In Guns, Germs, and Steel, Diamond says that agriculture was invented at least 4 separate times and possibly (IIRC) up to 7. All of these happened within about a 5000 year period at the beginning of the Holocene.

The populations have been separated as long as 40K years, so it’s unlikely to be a genetic change. What’s the likelihood that a similar genetic change happened in three or four completely isolated populations? (Australia, New Guinea, the Americans, and the Old World)

Any necessary common genetic change would have to be 40Ky old, since that’s when the Australian and New Guinea populations split off. So, I don’t buy that.

I’m sticking with climate as being most significant, but another factor (mentioned above as “standing on the shoulders of giants”) could be that a certain level of cultural development (e.g., sufficiently sophistcated language) was necessary, and which could have developed naturally and independently in the various populations.

But still, 30Ky and no obvious ag, and then in a 5 or 6ky span, at least 4 separate cases of the same novelty, leads me to suspect a synchronizing factor, which would be climate.

Above, there are posts about the rapid rise of ag in the Americas. As stated in my post here, I agree with what I think is the point there. However, the spread of ag in the Americas was very slow (assuming Mexico-area and Peru-area development was independent; which is arguable but not conclusive). Diamond points out that ag spreads quite quickly east/west, but much more slowly north/south, due to climate. He shows that ag did seem to spread quickly in the Old World, and much more slowly in the Americas, and posits that the north-south topography of the Americas is the reason.

(BTW, Azimov would have loved Diamond’s approach to archeology, which is the closest thing I know of to psychohistory. And probably the closest that it’s possible to get, outside of fiction. :wink: )

82

This is all really good stuff and I hate to interrupt but I need call in an ignorance casualty check real quick (then we can get back to H/G vs. Farmers).

  1. There was something very, very humanlike trotting about in Africa at least as early as 200k years ago, some online sites say 300k, but I’m willing to believe the older critters were really close physically but not quite modern in subtle but important ways. But sometime in between there was something that was damn near human.

  2. Damn Near Human slipped out of Africa about 100k years ago, became Damn Near Extinct Human 60k years ago but then recovered. XT doesn’t speculate as to what happened to pretty near wipe us out but it is interesting to note that our recovery coincides with apparent physiological changes that allowed us to speak. At any rate, we slipped out of Africa most likely through Sinai (and somehow got to Australia pretty quickly as well) and fiddled about with H/G & Agriculture for 35-40k years before taking the path that led to even sven forgetting how to spell menstruation.

  3. :frowning:

60-70k years from Start to Now is believable, especially if it looks like the first wave out of Africa became nonviable for some reason or other and got replaced by the same thing except with linguistic skillz. Smart, tool-using critter + capability of complex spoken language + capability of symbolic thought(paintings) + thumbs = Trouble for anyone else. That about right?

Which still leaves us the mystery of the neanderthals. Maybe they simply out-competed the first wave when Trouble happened, and were absorbed by the second wave (as I think current research is suggesting).

83

I favor the gradualist explanation. It’s not very likely that some HG woke up one morning and convinced everyone to abandon their lifestyle and start farming. A number of similar gradual scenarios were outlined above and seem more plausible; mostly, spending more time and effort each generation to tending the plants, eventually (in the right geographical areas) leading to full-time year-round settlements.

Once we have constant occupation, we can begin to accumulate more property than we can carry, which leads to more specialization of tool production and art.

My understanding is that the early ag civilizations were redistributive economies, ruling classes, and standing armies of full-time warriors. These aren’t possible without ag. But I wonder how those transitions happened, especially the redistributive economy. Did the first guy with a still evolve into the god-kings? (OK, not a still, but whatever it took to make the predecessor of beer.)

84

I think all you’d need for that is to leave the lid off a pot of grain during the rainy season and drink the result (perhaps out of thirsty desperation) a couple months later.

85

You don’t need a degree in reproductive health to realize that the tribe over there that placates the moon goddess by avoiding intercourse at certain times always seems to have a lot of kids running around, while you, who bangs away all month, somehow have fewer.

But it is true that if you have practice breeding domestic animals (as in, trying to get more reproductive capacity out of them than is found naturally), you are going to pick up on some basic concepts.

Again, fertility is the near universal cult of all farmers. This isn’t some crazy supposition. Walk up to any low-technology sustenance farmer in Niger or India or Suriname and ask them what they want in a wife, and they will say “fertility.” Ask them what they pray for, and they will say “fertility.” Ask them who is the most prestigious dude in the village, and they will say “the guy with the most kids.” Agriculturalists literally live and die by their kids, and all of agricultural society- and especially very relevant stuff like marriage laws and sexual customs- maximize and control fertility. Even if they do not have a perfect grasp of how all these mechanisms work, they still work.

I don’t thing being a hunter-gatherer was all sunshine and roses. But I know that being a low-technology farmer is basically the absolute pits, and nobody wants to do it if they have other choices. Even today, people are draining out of rural areas as fast as they can, even if that means they live in a cardboard slum on the railroad tracks. Farming sucks.

(And yes, you can be healthy and not particularly fertile- it’s extremely common among athletes…and my apologies for the poor spelling, my phone is being difficult today.)

86

Actually I would dispute that.
Not that you would need a degree, but to notice a very slight increased probability of a higher birth rate among one small group relative to another (and it would be very slight), would be noticed and automatically linked to a superstition about menstruation.

More plausible, but still not self-evidently obvious to me.
Conception is never 100% successful, so you’d probably learn to give the males a few goes at it. To notice it doesn’t work so well if all of the goes happen during M…it’s possible, but I’d still like to see some evidence.

It’s up there, but I would dispute it always top over things like the weather and good health. Also, it has to be shown that they care more about fertility than H-Gs.

Yeah but don’t forget that the causality often runs the other way: the strongest, most respected guy gets to screw as much as he likes.

Well, you can look at it by analogy to the industrial revolution. Working in an early factory looks like hell to me, but guys from rural areas flooded into the cities for this kind of work. It was preferable to them.
Similarly, while subsistence farming looks horrible to us (and those factory workers), it may well have been preferable to the H-G lifestyle, which does seem to be getting painted in a rosy way, since Diamond’s take.

Depends on your definition of healthy. Being able to run fast doesn’t automatically mean you’re healthy.

87

I think we’re limited in learning about early Ags and HGs by observing modern versions. There are some similarities no doubt, but modern HGs are all limited in their range and have to compete with modern societies for resources. And we can’t possibly draw conclusions about the socio-economic status of early Ags based on their modern counterparts.

I don’t know how we try to determine birth rates in these groups, but HG life must have been perilous leading to lower population growth, but I’m just guessing on that one.

88

The phycological mindset of modern humans changed after a falling out with God. We stopped living for the day and began a whole host of behavior that resulted in the modern world that we live in today (Genesis 3). There was no desire for humans to live beyond what nature proved before this event.

89

don’t think this is a factual answer, but with a Jul 2013 join date may be an honest mistake.

90

Moderator Note

Souhradat, General Questions is for factual information. This is essentially religious witnessing, and doesn’t belong here. If you must discuss your religious beliefs, do it in Great Debates. Don’t make further posts of this kind in General Questions.

Colibri
General Questions Moderator

91

I’m learning here, okay? So, for example, 30k means 30,000, right? What does y mean? a?

So is it accepted that climatic change caused the precipitous drop in population 60-70,000 years ago? or what?
And what led to the come-back?

92

Only a creationist would assume this.

Evolution labors on, every generation.

A single substitution of cytosine for thymine in HGMA2 confers an “intelligence” advantage (perhaps by increasing brain size). MCPH2 haplogroup D variant is so startlingly penetrated in mtDNA post L3 M/N-split lineages that it’s highly likely this variant has positive selection pressure driving this ubiquity, in turn secondary to it conferring a reproductive advantage. If we assume that intelligence creates a reproductive advantage, especially in a world with climate-associated environmental changes requiring an intelligent response to survive, we would expect that all descendant lineages from L0 onward have had evolution-driven advances in “intelligence” with each descendant population having an increasing penetration of advantageous genes even though all current lineages are still in the general category of “anatomically modern humans” that L0 was.

Because traits like “intelligence” and “creativity” are polygenic–as is neurophysiologic function in toto–it’s a complicated picture to parse out WRT individual populations (although within modern SIRE categories, many genes have been shown to be positively selected). But one thing is for sure: current humans are not that guy 200K years ago, and if intelligence confers a reproductive advantage, odds are that we are smarter and more innovative because we have continued to evolve.

93

The cause of the population drop is thought to have been a supervolcanic eruption, that of Toba. ya = years ago.

94

Interesting that the article discusses stone tools in India from the 65kya era.

95

At what point in time could we pluck a human baby from the past, raise him/her in the modern day world, and that baby would develop to become an adult of average, above average, or even of Mensa grade intelligence?

96

There’s no real way of saying, of course.

And, CP is maybe (unintentionally?) overstating the role of genetics in intelligence.

One of the single biggest factors in the success of modern education is simply ensuring the kids have adequate nutrition. Even the mother’s nutrition plays an important role here, as healthier mothers generally produce healthier babies. It’d be difficult (probably impossible) to determine how much more or less intelligent the average human being is compared to counterparts from the distant past, much less even a few centuries ago and how much of this is biological and how much due to environment.

97

edit

98

The success of modern education is not dependent upon good nutrition.

It is not impossible to sort out the role of genetics in intelligence.

Intelligence is highly hereditable. I agree that it is impossible to quantify how the average L0 might compare with the average modern Ashkenazi (for example) but it seems unlikely that evolution would take h sapiens down the highly intelligent path and then stop selecting for it. And to the point of the OP, the evidence is that prior population lineages didn’t get too far figuring stuff out. There is no basis whatever for the assumption humans 200k years ago were as intelligent as modern populations.

What is often referred to as a “behavioural” change or a “cultural” shift can equally be attributed to genetically driven neurophysiological changes underpinning the advances. Contrary to modern euphemisms minimizing skillset differences, populations don’t “discover” agriculture as if it were serendipitously lying under a bush in their backyard. They figure it out. And that takes brains along with serendipity.

99

Thanks Quartz.

100

That’s highly debatable.

We know we have sees measurable, sizable benefits in educational attainment from the national school lunch program.

Feeding kids leads directly to improved performance not only in school but after they leave school.

In terms of dollars spent, there are worse ways to educate children than making sure they aren’t going hungry.

As for intelligence, are we selecting for intelligence? That’s not precisely how selection works all the time, is it? It’s more that there’s not much to actively select against intelligence.

Over 200k years, we can reasonably guess (though not prove) there’s been sufficient time for our population to gain that much more intelligence. But over the last 50k years? The last 5k years? The last 500 years? That’s a bit more questionable. And there are unfortunately few physical clues to tell us. We do know our brains have gradually been shrinking over the last 20000 years. But what does that mean? That we are losing intelligence or merely becoming more efficient thinkers? We don’t really know, though there are proponents for both theories.