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The situation is that an alien race transplanted a single tribe of about 10,000 primitive genetically homogeneous humans to a distant but livable planet. I want to know how much this initial population would genetically diverge over about 200,000 years as they grow from a stone age existence to an advanced civilization.

The issue is I'm not sure how to depict them. Would they still appear to be largely homogeneous because of the Founder Effect? Would the variations be relatively minor? Or would there be completely different geographical variations and nations who could no longer recognize each other?

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    $\begingroup$ Ethnicity is a cultural attribute; it changes very fast. For example, consider Europe in the 1st century AD and in the 21st century AD, a distance of 2000 years: the only "nation" of the 1st century which still exists are the Greeks. ("Nation" in scare quotes because it's arguably improper to speak of nations before the Renaissance.) All other nations of the 1st century are gone, to be mixed and replaced by new nations. For another well-known example, there is a well-known, numerous and powerful nation in North America which appeared ex nihilo less than 300 years ago... $\endgroup$ – AlexP Sep 16 '17 at 18:12
  • $\begingroup$ Going by biblical history, it didn't take long for a "tribe" of about eight people who survived the flood to go on to create a variety of nations. As a side note (also going by biblical history), the flood took place somewhere around 2400 BC. $\endgroup$ – JustSnilloc Sep 16 '17 at 20:09
  • $\begingroup$ If we are cross referencing what genealogists have come to the conclusion of, then we could also assume that Noah's family was what we would consider African, but there's no evidence to suggest that all eight were homogeneous in terms of racial profile. That being said, genetic mutations and adaptations could be considered the cause for today's many races. $\endgroup$ – JustSnilloc Sep 16 '17 at 20:16
  • $\begingroup$ @JustSnilloc Noah's family had some built in variability with his sons' wives, who could have had any kind of heritage. Also, in that book of the Bible, weren't people living very long lives and having more children? $\endgroup$ – TheLeopard Sep 16 '17 at 20:57
  • $\begingroup$ @TheLeopard Right, that's why I mentioned that all eight might not have shared the same race. As per lifespans, they were pretty long. While I wasn't considering that as a factor, a single person living for multiple "generations" is pretty big. They slowly dwindled down in years generation after generation. Noah died at 950, his son died at 600. Two generations later a man lived to 433, and two generations after that a man lived to 239. Three generations later a man died at 148, and while some later generations lived slightly longer than that, it slowly dwindled down to "normal" after a while. $\endgroup$ – JustSnilloc Sep 16 '17 at 22:34
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Aha. I think I have it. And I think it is politically correct and biologically acceptable, huzzah!

"How long before two populations of people that, if genome-sequenced and subjected to NPMD, would form discrete (i.e. non overlapping) genetic groups."

Let's give those two groups a friendly name, like "Blossoms." These two blossoms originated from a single blossom. They can interbreed, but at the moment that we are observing this world, they isolate from one another and do not interbreed, by choice or force. << That's the question I am answering now. :-D

~~~

You need a few things to drive the establishment of different blossoms.

  1. Reproductive isolation. If some of your tribe was unable to mate with others of the tribe due to geographic isolation or cultural isolation (e.g. class structure, etc), then you will begin to have multiple distinct gene pools.

This is the most important feature, IMO, to drive the establishment of different blossoms.

  1. Different selective pressures. These can result from groups living in different environments, or could be due to socioeconomic differences (some have access to healthcare and others don't, etc.) Et cetera. Introduce different selections on the groups. Skin color in humans resulted from sun exposure; Nordic peoples are light and tropical peoples are dark, etc.

  2. I believe random genetic drift has some play here, but it has been a while and I don't recall the details of that.

  3. I believe small populations become genetically distinct faster than large populations. So you can carve up your population into small bits.

So, if you devise an extreme scenario you can easily have as many different blossoms as you like - probably in a matter of 10 generations (at a guess.) On the other hand if everyone stays together geographically and culturally, and mates randomly, the population will remain homogenous.

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  • $\begingroup$ From the online searches I've been doing, I've been getting things like modern humans separated from Neanderthals about 40,000 years ago, etc. which is an ok guideline, but we just know so little about pre-history that far back. The population of Iceland hasn't changed much physically in 1000 years. A quote from Quora: "That would put the human speciation separation time about 100 - 500,000 years. Figuring 20–25 years per generation, that gives 4000 - 25,000 generations." quora.com/… $\endgroup$ – TheLeopard Sep 16 '17 at 18:09
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    $\begingroup$ Ethnicity is cultural. It has nothing to do with how people look. Unlike physical attributes, ethnicity changes very very fast; for example, the well-known American nation was formed in a little more than one century. $\endgroup$ – AlexP Sep 16 '17 at 18:16
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    $\begingroup$ @DPT The meaning of the word race has changed drastically over 150 years. People used to say "the Irish race" or even refer to someone's extended family descendants as "he and all his race have always been good fishermen." Here's another interesting quote, this one from Eupedia: But since Neanderthals evolved alongside Homo Sapiens for 600,000 years, and had numerous subspecies across all Europe, the Middle East and Central Asia, it cannot be ruled out that one particular subspecies of Neanderthal passed on the MC1R mutation to Homo Sapiens. $\endgroup$ – TheLeopard Sep 16 '17 at 18:24
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    $\begingroup$ @DPT I'd like to point out that "race" really isn't a useful biological term (which is the reason why its so seldom used in the field nowadays), there are too many conflicting definitions and cultural baggage associated with it. When people attempted to classify humans into distinct races, what they were really doing was simply identifying a very obvious physical trait (most notably skin color) and using that as a marker with no baring to genetics. Indeed as TheLeopard points out, there is more genetic variation within the populations of the commonly proposed "races" than between then. $\endgroup$ – AngelPray Sep 16 '17 at 18:35
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    $\begingroup$ @DPT: The phrase you are looking for is "geographical varieties". "Races" as commonly understood do not exist in nature and are culturally defined; for example, Americans and Europeans have widely different "racial" systems, so much that it is quite difficult to understand what an American policeman means by "Latino" or "Caucasian" in a movie. (For me, a "Caucasian" would be somebody from the Caucasus, an Ingush, a Daghestani, a Chechen, maybe a Georgian; I mentally translate the American word "Caucasian" to "pale-skinned white person". I have no idea what a "Latino" is and how recognize one.) $\endgroup$ – AlexP Sep 16 '17 at 18:53
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Ethically, they'd be unrecognizable. The most interesting bit that you're leaving out is how biologically different they would be.

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200,000 years is roughly 40 times all or recorded history. No single nation has survived this long, so there is absolutely no reason to believe these people would have a unified nation. Actually given the fact that they are stone age people, there is no reason to believe they would have history going back 200,000 years.

As for how they change over 200,000 years, they change completely. Again this is a 40 times longer window than it took for all of human history, you could fill buildings upon buildings with the record of how much they change.

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You'll get lots of physical differences in your 200,000 years if your people spread out across the planet to live in different environments. For instance, body proportions: being fairly short and squat is a good body shape to have in a cold climate, because it minimises your surface area to volume ratio, and reduces heat loss. This is called Allen's Rule. So natural selection would favour short, chunky people in the Arctic or cold upland areas in mountain ranges. But you would find tall and skinny is good in hot climates where you want a large skin area to sweat from. Pale skinned people will get skin cancer a lot in the tropics, so any darker pigmented offspring will be favoured by natural selection.

Survival tactics in different climates may drive differing traditions. The Arctic lot will have superstitions about seal hunting and reindeer herding (or the alien equivalent of seals and reindeer). The desert lot will have superstitions about sand storms and oases.

Also there are bound to have been schisms in 200,000 years. One lot believe the aliens who brought them there were benevolent gods, another that they are devils. They spilt apart and develop separate cultures over the generations.

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  • $\begingroup$ Thanks for answer and Allen's Rule link! Very interesting reading. $\endgroup$ – TheLeopard Sep 17 '17 at 15:38
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Given that the African diaspora occurred ~60K years ago, EVERY current human variation, ethnicity, and nation evolved in that time. Granted, early homo sapien tribes intermixed with the existing human like groups, but there was still a dominate species of human, originating from a small geographic area, that covered most of the planet in a relatively short period of time (20-30 millennia).

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So your 10K transplants would have some challenges. For starters, what is the geography? Does it facilitate easy migration. Is there an ice age that opens up land bridges between islands/continents? Are serious macropredators limited enough for primitive man to cope? I doubt you could scoop up 10K folks from any Earth hunter-gatherer era and have them all consider themselves "one tribe", but genetically at least this may be true, especially if you pick a time right after a large scale global disaster that wiped out lots of other groups of humans. Right after, for example, the Toba supervolcano in 70,000 BCE that really culled the human diversity on the planet (more info on Toba) you could find spots that repopulated from just a few breeder pairs and would have a lot of genetic similarities.

Lack of any forerunner hominids to pass on skills/demonstrate how to live in a new area will slow expansion into new biomes. The variety of challenging environments will be one of the largest drivers for increased diversity/differentiation, especially for low tech humans that can't alter the planet to suit them. All of our instinctual knowledge will be wrong, it will take time to develop new ingrained responses for this new planet, passing on the information via epigenetics to offspring (if you ascribe to that theory) and redeveloping an oral tradition.

200K years, barring significant mass extinctions or harsh climate change, should be plenty of time for physically very different humans to develop, each with their own language roots and unique cultures. In fact, if they have fewer mass extinctions and the geography and native flora/fauna are agreeable, there is no reason why this hunter-gather group couldn't develop agriculture, domesticated animals, and eventually advanced technology much faster than humans did on earth, so your group could be space faring themselves in just 10-15K years! For all of it's flaws, Jared Diamonds Guns' Germs, and Steel can give you ideas on how to craft a world to accelerate or retard human development.

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Consider the Polynesians. It's generally thought that they started spreading from Taiwan roughly 4000-5000 years ago, and by 1000 A.D. they had spread to many diverse cultures and populations across the various Pacific islands. That an other historical records show that humanity spread and diversified quite quickly.

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