A queston on Human evolution

[excavating_for_a_mind]

Current scientific thought has Homo sapiens appearing about 50,000 years ago, I believe. At any rate, as far as 30,000 years ago, humans could be found in Europe, Asia, Africa, Australia, and the Americas. My understanding is that these humans were essentially the same as we are today. That is, if you had a time machine and obtained an infant born 50,000 years ago and brought them to the present day, he would more than capable of learning things like differential calculus (although that might take nearly 20 years; it did me).

Is this correct, or were there additional genetic changes in our species that allow us to be superior thinkers and if so, what were those changes?

If this is correct, why did it take so long for humans to develop the written word? Human history extends only for 5000 years or so (I believe). Is it just coincidental that metal tools seem to begin showing up at around the same time?

[MrDibble]

@excavating_for_a_mind

Current scientific thought has Homo sapiens appearing about 50,000 years ago, I believe.

Nope. 100,000-200,000 years ago.

Is this correct

Yes, even if you take the latest date for behavioral modernity (I personally don’t)

If this is correct, why did it take so long for humans to develop the written word?

No need, before, would be my guess. Writing appears to be a product of settlement and commerce, as opposed to a prerequisite for same.

Human history extends only for 5000 years or so (I believe). Is it just coincidental that metal tools seem to begin showing up at around the same time?

No, metal tools are also a product of settlement and the associated culture patterns.

[Darren_Garrison]

These are not easy questions to answer when your only basis is scraps of bones and artifacts left behind. One problem is defining when people started being Homo sapiens and stopped being an earlier species in the first place (a broad, fuzzy zone, not a sharp borderline.) Fossils of what are termed anatomically modern humans date back around 200 thousand years–this just means that the skeletons (including the capacity of the cranium) are more or less pretty much like those of modern humans (a fairly vague statement for a fairly vague set of traits–there is a fair variety of skeletal/skull shapes 200,000 years ago just as there are in humans today.)

The 50,000 years BP you are thinking of (already linked in the above post on behavioral modernity) is also called “the great leap forward” (you can google for tons of hits to sort through) which is a time period when it seems that humans suddenly started using more complex tools than they used before–and which may represent a spike in intelligence, or may be an artifact created by the scattered nature of artifacts being preserved.

Metal and writing might be products of becoming settled agriculturalists. Discovering how to smelt metal may be a direct result of learning how to make high-temperature ceramics, for example–and carrying around heavy, brittle ceramics would have been less suitable for nomadic cultures than containers made of animal skin or woven plant fibers, so ceramic technology wouldn’t have really taken off until populations became more-or-less settled.

Writing? Again, something that would have been had to carried around in nomadic societies. And learning to read and write takes a long time, not something very suitable for the low population density of hunter-gatherers. Works better in a dense society that can support specialized teachers and a population of (relatively) idle students.

So the question might be better framed not as “why did it take so long to start refining metal and invent writing” but “why did it take so long to become settled agricultural societies.” (Or "why stop being hunter-gatherers at all.)

tl;dr–Insufficient information for concrete answers, so everyone has to speculate based on the scraps of clues that we have.

[Blue_Blistering_Barnacle]

People with parents born to stone age cultures (Like New Guinea) can fly planes.

So, yes, you can kidnap Og’s child, raise her in a modern home, send her to private school, and watch her challenge the blue-bloods. (If you can just keep her off those devices!)

[TriPolar]

The written word is a form of communication that requires a certain amount of ‘infrastructure’. You need something to write with, something to write on, some useful information to write down, and someone else who knows how to read. Humans surely communicated non-verbally with at least gestures, likely made marks on trees or chipped stones in ways to be interpreted by others. They may have scratched drawings in the dirt. Cave art approx. 40,000 years old has been found, some of the oldest art may have been purely esthetic, some appears to tell stories. In hunter-gatherer tribes there isn’t much need for writing, everyone you want to talk to is nearby. Writing is useful for long distance and long term communication, not needed until later on in human history.

[dofe]

Good username/topic combo!

@TriPolar

In hunter-gatherer tribes there isn’t much need for writing, everyone you want to talk to is nearby. Writing is useful for long distance and long term communication, not needed until later on in human history.

That certainly makes sense. I believe that even most of the hunter-gatherer societies that survived to the modern age (e.g., the bushmen in southern Africa and the various uncontacted tribes in South America) never developed writing.

[Chronos]

There was in fact a huge leap forward in human intellect at the time of the development of writing. That leap forward was the development of writing itself. It’s apparently a tough idea to come up with from scratch, but once you do come up with it, it makes it really easy to preserve all sorts of ideas, including itself.

[Der_Trihs]

Consider that Sequoyah created the written form of the Cherokee language by himself, with no more than the knowledge by observation that it was possible to encode language that way. And leaped over thousands of years of progress in writing when he did it; his creation was much more sophisticated than the earliest writing systems (which were mostly for agricultural notekeeping and the like).

To me, that says that the inspiration that it’s* possible* is of key importance. He knew it could be done, and realized it *wasn’t *magic, and so was something he could reason out for himself. And he did. Presumably any number of people could have done the same in previous centuries; but they didn’t have that initial inspiration, nor a perceived need to look for one.

Organized agricultural societies presumably have their own “inspiration” in necessity; “necessity is the mother of invention” and all that. They* need* it, so eventually after enough search for a solution they invent it; hunter gatherers don’t need it.

[Xema]

@dofe

I believe that even most of the hunter-gatherer societies that survived to the modern age (e.g., the bushmen in southern Africa and the various uncontacted tribes in South America) never developed writing.

I’d be interested to know whether any hunter-gatherer society had written language. It seems like the conditions for written language imply things (e.g. accounts of assets) not significant in H-G societies, and that any society with it soon moves into agriculture, complex trade and so forth.

[Leo_Bloom]

@Chronos

There was in fact a huge leap forward in human intellect at the time of the development of writing…

Huh? We’re talking of the evolution of the organism.

[Chronos]

But human intellect is no longer bound by the limitations of the organism.

[UDS]

@Xema

I’d be interested to know whether any hunter-gatherer society had written language. It seems like the conditions for written language imply things (e.g. accounts of assets) not significant in H-G societies, and that any society with it soon moves into agriculture, complex trade and so forth.

It depends on what you mean by “written language”. Hunter-gatherer societies certainly have represenational art, and they use it for a variety of purposes involving communication - to tell a story, for instruction in skills or useful/important knowledge (though it mostly functions as a visual aid to verbal instruction), as “signage” to, e.g, indicate that a place is significant, and to state the nature of the significance.

[md2000]

The question is why agriculture took so long but then seems to have happened everywhere almost at once. The people of 10,000 years ago probably did not differ evolution-wise from 20,000 or 30,000 years ago. yet the people who split off about 24,000 years ago, in Siberia where there was no agriculture, and trekked across (or boated along) the route to the Americas, still managed to not only independently discover agriculture, but developed corn, which started from a simple grass-like plant to become a large staple crop unable to survive in the wild.

or…maybe it’s just getting a large enough population in one place with the right climate and vegetation.

One theory also says that the 70,000 years ago bottleneck might have been the evolutionary pressure where a significant new development - language, abstract thought and planning, whatever - caused a small population to force out all others.

Various articles suggest the modern human population is descended from a bottleneck of 3,000 to 10,000 people (actually quite large when you consider tribal hunting groups of one to two dozen to be the norm). Perhaps it was something as simple as luck surviving global winter from the great volcanic eruption, perhaps it was weeding out by the best and brightest - the two scenarios are not mutually exclusive.

Also note that these humans did not do anything that assorted variants - Neanderthal, Peking man, Java man - had not done before them. IIRC Europe had been inhabited by Neaderthals for 200,000-plus years before modern man wiped them out or “displaced” them (with some assimilation) between 50,000 to 35,000 years ago.

Yes, hunter gatherers had no need of writing to any extent; small groups could say what they wanted. Writing is a permanent record to pass on to someone who for assorted reasons - time, distance, population size - cannot remember what you have to say. (Original writing was “bills of lading” for Mesopotamian caravans)

[RivkahChaya]

It’s possible that lots of people had private pictographic systems they used that don’t survive because they didn’t leave enough behind. It took an organized society with time for pedagogy to have an agreed-upon system that lots of people shared and used to communicate amongst themselves, before you had the beginnings of an alphabet. Then, you needed a system of teaching it to other, and the time to do it, before it was useful. There was a time when even the children of the privileged had to work during the day, because privileged just meant having the most land to farm, and the most animals to care for.

Pictographic symbols in some of the most ancient alphabets that survive appear to have once stood for common objects, then came to stand for the first sound in the name of that object, until eventually the alphabet was left with the smallest number of symbols it needed to stand for every sound. The best evidence is that Hebrew evolved that was, and Chinese still works that way.

[MrDibble]

@dofe

hunter-gatherer societies [—snip…] the various uncontacted tribes in South America)

Note that as far as I’m aware, most uncontacted Amazonians don’t appear to be hunter-gatherers, they practice swidden-type (slash&burn) agriculture as well.

Also, it might be a bit misleading to consider their current state as representing some cultural steady-state, some of those tribes arelikely descended from prehistoric settled agrarian polities that numbered in the tens of thousands, and even made geometric symbols as geoglyphs - It’s all somewhat similar to the way the North American Cahokia/Missisipian mound builder cultures devolved later. While the Missisipians hadn’t yet developed writing, they were probably heading there with their rich & complexsymbology set.

[Riemann]

@Leo_Bloom

Huh? We’re talking of the evolution of the organism.

I think this the moot point of the OP.

Obviously, our big brains first evolved biologically. But the question is, how and when did certain skills arise? We have a high level of general problem-solving intelligence, but some mental skills such as language seem to be attributable so specialized mental “modules” that are qualitatively (not just quantitatively) lacking in other animals. So, to what extent was the timing of the emergence of certain mental abilities attributable to incremental genetic change (further biological evolution) and to what extent was it attributable to invention and cultural development?

To put it another way, as did the OP: how far back do you have to go to find a brain that was genetically substantially different from a modern brain?

[Banksiaman]

@Riemann

I think this the moot point of the OP.

… To put it another way, as did the OP: how far back do you have to go to find a brain that was genetically substantially different from a modern brain?

The most recent genetic work on Australian Aboriginal people supports their position as the first of the migrating waves of modern Homo sapiens to expand into previously unoccupied lands, sometime 70-50,000 ish Before Present. Only modest later genetic admixture Later on. For the purposes of this discussion we might consider them thoroughly modern, and being indistinguishable in intellectual capabilities from any other global citizens.

So we need to look further back than 70,000 years and the spread of modern people. Neanderthals are argued by some to be behaviourally and cognitively different, and they diverged from modern Homo ?500,000 years ago.

Would they be significantly different? Dunno.

[Riemann]

Unfortunately, we have so little understanding of genotype>phenotype in building a brain that even we miraculously had the genome sequences of a series of ancestral humans it probably would not tell us much. After all, we have very little idea which genetic differences between humans and chimps account for the differences in our brains. We have no ethically acceptable model organism for large brain genetics experiments, of course. Even if monkey experiments were ethically ok, doing monkey genetics is not too practical; although CRISPR could change that I guess.

[Wesley_Clark]

Here is a list from wikipedia about potential causes of the neolithic revolution, which among other things led to writing.

Neolithic Revolution

The Oasis Theory, originally proposed by Raphael Pumpelly in 1908, popularized by V. Gordon Childe in 1928 and summarised in Childe’s book Man Makes Himself.[16] This theory maintains that as the climate got drier due to the Atlantic depressions shifting northward, communities contracted to oases where they were forced into close association with animals, which were then domesticated together with planting of seeds. However, today this theory has little support amongst archaeologists because subsequent climate data suggests that the region was getting wetter rather than drier.[17]

The Hilly Flanks hypothesis, proposed by Robert Braidwood in 1948, suggests that agriculture began in the hilly flanks of the Taurus and Zagros mountains, where the climate was not drier as Childe had believed, and fertile land supported a variety of plants and animals amenable to domestication.[18]

The Feasting model by Brian Hayden[19] suggests that agriculture was driven by ostentatious displays of power, such as giving feasts, to exert dominance. This required assembling large quantities of food, which drove agricultural technology.

The Demographic theories proposed by Carl Sauer[20] and adapted by Lewis Binford[21] and Kent Flannery posit an increasingly sedentary population that expanded up to the carrying capacity of the local environment and required more food than could be gathered. Various social and economic factors helped drive the need for food.

The evolutionary/intentionality theory, developed by David Rindos[22] and others, views agriculture as an evolutionary adaptation of plants and humans. Starting with domestication by protection of wild plants, it led to specialization of location and then full-fledged domestication.

Peter Richerson, Robert Boyd, and Robert Bettinger[23] make a case for the development of agriculture coinciding with an increasingly stable climate at the beginning of the Holocene. Ronald Wright’s book and Massey Lecture Series A Short History of Progress[24] popularized this hypothesis.

The postulated Younger Dryas impact event, claimed to be in part responsible for megafauna extinction and ending the last glacial period, could have provided circumstances that required the evolution of agricultural societies for humanity to survive.[25] The agrarian revolution itself is a reflection of typical overpopulation by certain species following initial events during extinction eras; this overpopulation itself ultimately propagates the extinction event.

Leonid Grinin argues that whatever plants were cultivated, the independent invention of agriculture always took place in special natural environments (e.g., South-East Asia). It is supposed that the cultivation of cereals started somewhere in the Near East: in the hills of Palestine or Egypt. So Grinin dates the beginning of the agricultural revolution within the interval 12,000 to 9,000 BP, though in some cases the first cultivated plants or domesticated animals’ bones are even of a more ancient age of 14–15 thousand years ago.[26]

Andrew Moore suggested that the Neolithic Revolution originated over long periods of development in the Levant, possibly beginning during the Epipaleolithic. In “A Reassessment of the Neolithic Revolution”, Frank Hole further expanded the relationship between plant and animal domestication. He suggested the events could have occurred independently over different periods of time, in as yet unexplored locations. He noted that no transition site had been found documenting the shift from what he termed immediate and delayed return social systems. He noted that the full range of domesticated animals (goats, sheep, cattle and pigs) were not found until the sixth millennium at Tell Ramad. Hole concluded that “close attention should be paid in future investigations to the western margins of the Euphrates basin, perhaps as far south as the Arabian Peninsula, especially where wadis carrying Pleistocene rainfall runoff flowed.”[27]

[md2000]

Anyone who’s done the sprouting bean experiments in grade school can see that a fruit leads to a new plant growing. Considering our ancestors did not have a lot else to distract them, I’m sure they noticed fruit/seeds turn into plants. (Kind of reminds me of the threads on “when did humans figure out sex caused pregnancy?”) We can speculate on the steps from knowing seeds germinated and made new plants, to deliberately burying food in quantity to get more food much later.