Human history begins with millions of years of hunter-gathering and lithic technology:

The Paleolithic ... is ... distinguished by the development of the most primitive stone tools ... and covers roughly 95% of human technological prehistory.

Then, within a few thousand years, there are multiple instances of independent developments associated with civilization, including agriculture, domestication, cities, writing, and politics:

Current scholarship generally identifies six sites where civilization emerged independently: Mesopotamia, the Nile River, the Indus River, the Yellow River, the Central Andes, and Mesoamerica.

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This seems rather a coincidence. Presumably, either the precursors for civilization were already in place 11-10 ka BP when the American migrants split off from the rest of the world, or there has been significant technology interchange since then. Is there an accepted (or at least dominant) explanation for the multiple coincidental independent technological booms that occurred in just the last few thousand years of human history?

Note: There are quite a few theories for the advent of the related "neolithic revolution", so I fear the answer to my question is "no", but figured I'd ask.

  • 8
    You could obviously eliminate the simultaneous Mideast/Egypt development as coincidence, since they were in pretty constant contact. It's not too much of a stretch to suppose that there was Mideast/India contact, or Mideast/China.
    – jamesqf
    Commented Feb 5, 2017 at 19:03
  • Adding to the previous comment from @jamesqf, I've read that the Oxus civilization (discovermagazine.com/2006/nov/…) may have had an important role in bridging China to the rest of Eurasia.
    – Brian Z
    Commented Feb 5, 2017 at 20:01
  • 1
    There's evidence that modern humans are actually only around 50,000 years old, and that there were changes that we can't see in the fossil record because they aren't preserved. (soft tissues, basically, including the brain.) If you buy that, the timing is less coincidental. We know that something changed around then, we just don't know if it was entirely cultural or there was a biological element.
    – user15620
    Commented Feb 7, 2017 at 20:36
  • Related question, more precisely phrased. 50,000 versus 10,000 years is still quite a coincidence.
    – kubanczyk
    Commented Mar 6, 2017 at 14:22
  • @kubanczyk Pushing the date back before the disappearance of Beringia makes this less of a coincidence because over that span of time, trade and knowledge transfer may mean that developments up till that point were not entirely independent. Developments that happened after thousands of years of isolation in the Americas seem like much more of a coincidence. Commented Mar 10, 2017 at 7:54

2 Answers 2


I also believe the answer is "no". It sure is tempting to put forth one's own theories here, but I'm unaware of any one that is generally accepted.

I will point out one thing though: That chart you posted is essentially a chart of literacy. If you use the dates there, you are asking a question about the discovery of writing in various places, not the "Neolithic revolution" itself (which was more about animal and plant domestication).

One thing we can say for sure about literacy is that societies quite happily emulate other ones when they see a useful innovation in writing. So it is generally thought that writing systems emerging so close together in Egypt and Mesopotamia is no coincidence (what is under dispute is who was first). The Indus Valley was in trade contact with Egypt, so in theory their literacy could have been borrowed too. However, the other 3 on the list were probably independent inventions.

I can't resist pointing out some interesting timing with domestication though. The current inter-glacial period we are living in started about 11,700 years ago. The earliest evidence we have of agriculture? Also 11,000 years ago.

Of course that's just (circumstantial) evidence of a correlation, not a causation. However, this is certainly what it would look like if mankind was poised for this genetically, and the Neolithic breakthrough was merely awaiting weather conditions that made agriculture a relatively worthwhile effort.

Likewise, the appearance of multiple independent writing systems in densely-habitated agricultural areas all over the globe looks an awful lot like writing is just something a society naturally has a good chance of developing, once it reaches a certain size.

  • 3
    I think writing is naturally going to evolve when you have trade and need to keep accounts of things. IIRC, some of the earliest "writing" in Mesopotamia consisted of little clay models of things that were shipped, inside a pottery envelope, along with the goods they represented, so if the figures didn't match when the customer broke the envelope, someone was cheating.
    – jamesqf
    Commented Feb 6, 2017 at 1:25
  • Actually writing did not emerge in South America, or the Indus Valley for example (at least not beyond proto-writing), so writing/literacy is not an "inevitable" or "natural" part of civilization. Commented Mar 10, 2017 at 8:00
  • @ArnonWeinberg - Incorrect. They had a native form of writing in both places.
    – T.E.D.
    Commented Mar 10, 2017 at 15:15
  • @T.E.D. References please? Quipu was not writing, and not invented until much much later, and the status of Indus Script as "writing" is still in dispute as far as I know since there are virtually no examples long enough to form sentences. Commented Mar 10, 2017 at 18:01
  • @T.E.D.: One will have to dive deep into the journals and reports, that's why i wont sacrifice a day worth of search, but yes, there are at least 3 independent centers of neolithisation: (1) based sheep/goat and emmer/einkorn in the fertile cresecent/anatolya/levant, (2) based in pig and rice in China, and (3) baed on maize and the lama/alpaca in Southern America. Just for completeness :-)
    – user41956
    Commented Feb 9, 2020 at 22:48

The Sahara Dried Up

While I agree with TED both that there probably isn't an accepted reason, and that the end of the Ice Age is likely related to the birth of agriculture, I do think it's worth mentioning a potentially more proximate event.

The most recent wet Sahara period began around 12,500BC and ended around 4,000BC, which is remarkably close to the start of urban civilizations in Eurasia.

The Sahara periodically receives long periods (1,000s of years) of rain, where it transforms into savanna, followed by even longer periods (10,000s of years) of drought and desertification. There's a theory that during these wet periods, people and animals from sub-Sarahan Africa and North Africa would expand into the new savanna, and then the return of the dry period would cause large migrations as the land became less and less productive.

So it's possible that climate change in Africa caused wave of migration that jump started urban civilization in Eurasia by pushing proto-civilizations in Egypt and Mesopotamia over some population threshold.

The wet Sahara Wikipedia link explicitly makes the above claim, but I don't know how widely accepted it is.

  • 2
    I know of the Wet Sahara, but everything I've read suggests that it's intimately tied to the Ice Age cycle. Can you cite reliable studies which support an independent cycle? Otherwise, the Wet Sahara cycle is simply part of the Ice Age cycle.
    – Mark Olson
    Commented Feb 28, 2023 at 20:11
  • @MarkOlson From : en.wikipedia.org/wiki/North_African_climate_cycles -- "A January 2019 MIT paper in Science Advances shows a cycle from wet to dry approximately every 20,000 years."
    – codeMonkey
    Commented Feb 28, 2023 at 22:34
  • Also - not sure why a Ice Age / wet Sahara linkage would matter. The sudden reduction in the size of the savanna is the proposed causal mechanism.
    – codeMonkey
    Commented Feb 28, 2023 at 22:45
  • 2
    The accepted answer already cited a connection to the ice ages. (Also, I'd note, that a drying Sahara may explain the development of civilizations in Egypt and Mesopotamia and maybe even the Indus valley, but not obviously in China or the Americas.)
    – Mark Olson
    Commented Feb 28, 2023 at 22:55

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