# What are the biggest questions remaining in the study of recent human evolution?

**URL:** <https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155>\
**Category:** Factual Questions\
**Created:** [July 2, 2018, 1:18pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155 "2018-07-02T13:18:10Z")\
**Posts on this page:** 20\
**Page:** 2

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**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\
**Post date:** [July 5, 2018, 2:25pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/21 "2018-07-05T14:25:54Z")

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> [@Colibri](#):
>
> The “Clovis first” hypothesis and the Ice-free Corridor as the first migration route have been dead as a doornail for many years.

Someone needs to alert Michael Shermer:

[![]( " - YouTube") ](https://www.youtube.com/watch?v=Kt49SRoi904)

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**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\
**Post date:** [July 5, 2018, 3:42pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/22 "2018-07-05T15:42:17Z")

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Someone also needs to alert Jared Diamond:

[https://www.edge.org/response-detail/27111](https://www.edge.org/response-detail/27111)

> [@](#):
>
> But any claim by an archaeologist to have discovered “the first X” is taken as a challenge by other archaeologists to discover an earlier X. In this case, archaeologists feel challenged to discover pre-Clovis sites, i.e. sites with different stone tools and dating to before 13,000 years ago. Every year nowadays, new claims of pre-Clovis sites in the U.S. and South America are advanced, and subjected to detailed scrutiny. Eventually, it turns out that most of those claims are invalidated by the equivalent of technical errors at step 37: e.g., the radiocarbon sample was contaminated with older carbon, or the radiocarbon-dated material really wasn’t associated with the stone tools. But, even after complicated analyses and objections and rebuttals, a few pre-Clovis claims have not yet been invalidated. At present, the most widely discussed such claims are for Chile’s Monte Verde site, Pennsylvania’s Meadowcroft site, and one site each in Texas and in Oregon. As a result, the majority of American archaeologists currently believe in the validity of pre-Clovis settlement.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 5, 2018, 3:44pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/23 "2018-07-05T15:44:06Z")

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[quote=“Surreal, post:21, topic:817155”]

Someone needs to alert Michael Shermer:

[/QUOTE]

Michael Shermer is neither an archaeologist nor a paleontologist (in fact he’s not a professional scientist at all), and I would not rely on Youtube videos for information on what’s up to date in science.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 5, 2018, 3:48pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/24 "2018-07-05T15:48:58Z")

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> [@Surreal](#):
>
> Someone also needs to alert Jared Diamond:
> 
> [Edge.org](https://www.edge.org/response-detail/27111)

That quote actually supports my point:

Quote:

> [@](#):
>
> But any claim by an archaeologist to have discovered “the first X” is taken as a challenge by other archaeologists to discover an earlier X. In this case, archaeologists feel challenged to discover pre-Clovis sites, i.e. sites with different stone tools and dating to before 13,000 years ago. Every year nowadays, new claims of pre-Clovis sites in the U.S. and South America are advanced, and subjected to detailed scrutiny. Eventually, it turns out that most of those claims are invalidated by the equivalent of technical errors at step 37: e.g., the radiocarbon sample was contaminated with older carbon, or the radiocarbon-dated material really wasn’t associated with the stone tools. **But, even after complicated analyses and objections and rebuttals, a few pre-Clovis claims have not yet been invalidated. At present, the most widely discussed such claims are for Chile’s Monte Verde site, Pennsylvania’s Meadowcroft site, and one site each in Texas and in Oregon. As a result, the majority of American archaeologists currently believe in the validity of pre-Clovis settlement.**

Bolding mine. As I said, Monte Verde has been widely accepted for going on 20 years now.

Look, I’ve developed major exhibitions including information on migrations into the Americas, and have consulted with leading archaeologists in the field. I’m aware of what the literature says.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 5, 2018, 3:54pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/25 "2018-07-05T15:54:03Z")

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> [@dtilque](#):
>
> Then how about [Bluefish Caves](https://www.archaeology.org/news/5206-170117-bluefish-caves-bones) in northern Yukon. Are the early dates (almost 25,000 years ago) widely accepted by archeologists?

I think it’s widely accepted that people had made their way into Beringia as well as Alaska and evidently part of the Yukon that long ago. These areas were largely ice-free even during the glacial maximums. But the interior routes south were blocked by the ice cap at that time.

From the article:

> [@](#):
>
> The researchers say these new dates support genetic research indicating a group of early migrants was isolated in Beringia, perhaps by glaciers, between 15,000 and 24,000 years ago.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 5, 2018, 4:02pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/26 "2018-07-05T16:02:43Z")

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> [@MrDibble](#):
>
> I don’t see why the same caveat wouldn’t hold for _sapiens_-Neanderthal interaction to explain the low blending.

That’s possible. Behavioral and cultural differences also could have limited interbreeding, but that would also qualify them as separate species under the Biological Species Concept. Many species that are genetically interfertile are kept isolated purely by differences in courtship behavior. But as I mentioned, there is also evidence for genetically-based reduced fertility in Neanderthal vs sapiens crosses.

And while it’s possible for cultural sanctions to reduce interbreeding between sapiens groups somewhat, they’ve never been very effective. As I said, the general result has been complete intermixture wherever the contact has endured for any time. Even when cultural sanctions have been extreme, as in the southern US up until the 1960s (or even much later), a great deal of interbreeding has occurred.

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**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\
**Post date:** [July 5, 2018, 4:23pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/27 "2018-07-05T16:23:15Z")

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Thanks for the further explanation, **Colibri**.

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**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\
**Post date:** [July 5, 2018, 6:48pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/28 "2018-07-05T18:48:18Z")

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First point - I have trouble imagining any human migration into a “land of plenty” like North America, which basically went nowhere. If humans made it to Pennsylvania, how did they not flourish and overpopulate the land as the later migration apparently did? Easter Island went from one or two isolated canoe-loads (OK, pretty big canoes) to thousands of people and an advanced civilization with only a few square miles to work with. North America we think the massive fauna was killed off by humans because they were to slow to realize humans were dangerous. How could a breeding pair no go forth and populate the earth under those circumstances? The one thing humans do really well is go forth an multiply. Pennsylvania is a long way for a solitary wanderer to get to. Ditto Monte Verde.

The other question - why agriculture? For 100,000 years (or 60,000 say) humans meandered across the landscape, then suddenly about 12,000 years ago humans discovered how to grow food, all of a sudden, in multiple locations. We can’t really blame climate, even during the ice ages humans must have been in ecozones that were amenable to agriculture.

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**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\
**Post date:** [July 6, 2018, 10:59am UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/29 "2018-07-06T10:59:09Z")

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> [@md2000](#):
>
> First point - I have trouble imagining any human migration into a “land of plenty” like North America, which basically went nowhere. If humans made it to Pennsylvania, how did they not flourish and overpopulate the land as the later migration apparently did?

Possibly a different toolset? If they didn’t use the same stone tools, they may not have had the right tools for clearing forest that later groups had.

> [@](#):
>
> We can’t really blame climate, even during the ice ages humans must have been in ecozones that were amenable to agriculture.

Not climate, but climate _change_, is the favoured explanation for at least a couple of domestication events.

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**Author:** ![iiandyiiii](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/iiandyiiii/32/7924_2.png) [@iiandyiiii](https://boards.straightdope.com/u/iiandyiiii)\
**Post date:** [July 6, 2018, 11:42am UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/30 "2018-07-06T11:42:44Z")

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Maybe new diseases could have killed off a small group that migrated? Larger numbers increase the survival chances, and maybe the first migrants were too few.

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**Author:** ![Banksiaman](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/banksiaman/32/3334_2.png) [@Banksiaman](https://boards.straightdope.com/u/Banksiaman)\
**Post date:** [July 6, 2018, 1:30pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/31 "2018-07-06T13:30:01Z")

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> [@iiandyiiii](#):
>
> Maybe new diseases could have killed off a small group that migrated? Larger numbers increase the survival chances, and maybe the first migrants were too few.

The principle on diseases is that the fewer or sparser the population there is, the harder it is for anything to spread. Some archaeologists have argued that the shift to sedentism as a result of urbanism and intensive agriculture, and eventually long-distance trade encouraged the spread of diseases that had previously not had that much impact on populations at all.

Agriculture emerges in multiple locations, but it can be an arbitrary line separating it from a range of reasonably intensive agricultural and pastoral practices that were going on for considerable periods. The more we find out about agriculture’s emergence, the harder it is to separate it from what went on before. Recent work - Bruce Pascoe’s Dark Emu is a good example - questions the very arbitrary Eurocentric, 19th century biblical way that agriculture is code for civilisation and dividing the world into advanced and primitive cultures.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 6, 2018, 3:11pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/32 "2018-07-06T15:11:21Z")

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> [@MrDibble](#):
>
> Possibly a different toolset? If they didn’t use the same stone tools, they may not have had the right tools for clearing forest that later groups had.

The early colonists of North America would have been hunters and gatherers. They were not clearing forests with stone tools. If they cleared forest (to improve hunting, for example) it would have been with fire.

> [@](#):
>
> Not climate, but climate _change_, is the favoured explanation for at least a couple of domestication events.

Agriculture appears to have originated independently and nearly simultaneously at widely separated places at around 10,000 years ago, at the Pleistocene-Holocene transition. The usual explanation is that climatic conditions during the Pleistocene were too variable to make settled agriculture feasible. Agriculture originated as climate stabilized at the end of the period. (Climatic instability has also been used as an explanation for the failure of agriculture to develop in Australia, even though related peoples developed agriculture in New Guinea.) I’m not sure how credible this is as an explanation, but that’s the prevailing wisdom.

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**Author:** ![MrDibble](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mrdibble/32/114_2.png) [@MrDibble](https://boards.straightdope.com/u/MrDibble)\
**Post date:** [July 7, 2018, 4:26pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/33 "2018-07-07T16:26:28Z")

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> [@Colibri](#):
>
> The early colonists of North America would have been hunters and gatherers. They were not clearing forests with stone tools. If they cleared forest (to improve hunting, for example) it would have been with fire.

Yes, I thought those were the ones **md2000** was asking about - the pre-agriculture ones. I mean, even in the post-Clovis cultures, there wasn’t anything we’d call “overpopulated” until we get to the near-collapse of the Mississippian and Ancestral Puebloan cultures (assuming overpopulation/resource depletion indeed played a role there, which seems likely), so I assumed those were the ones being contrasted.

If the distinction is merely pre-Clovis and Clovis-and-onwards, I don’t see enough of a distinction in the settlement habits to even raise the question.

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**Author:** ![Colibri](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/colibri/32/1841_2.png) [@Colibri](https://boards.straightdope.com/u/Colibri)\
**Post date:** [July 7, 2018, 4:37pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/34 "2018-07-07T16:37:06Z")

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> [@MrDibble](#):
>
> Yes, I thought those were the ones **md2000** was asking about - the pre-agriculture ones. I mean, even in the post-Clovis cultures, there wasn’t anything we’d call “overpopulated” until we get to the near-collapse of the Mississippian and Ancestral Puebloan cultures (assuming overpopulation/resource depletion indeed played a role there, which seems likely), so I assumed those were the ones being contrasted.
> 
> If the distinction is merely pre-Clovis and Clovis-and-onwards, I don’t see enough of a distinction in the settlement habits to even raise the question.

Clovis appears to be a culture specifically adapted to big-game hunting. They made very large projectile points with channels on the side so they could be hafted to a shaft, and they probably used atlatls or spear-throwers to increase the range and force with which they could throw a spear. They probably particularly focused on large game like mastodonts, giant ground sloths, and horses. Similar cultures are found around the same time in Central and South America.

The Clovis spear-point technology spread very rapidly through North America as far south as Panama. This was originally interpreted as the rapid migration of the first colonists through the hemisphere wiping out the megafauna as they went. (Paul Martin’s “Pleistocene Overkill” or “blitzkrieg” hypothesis.) This has since been refuted, and it may have been just the technology that spread rather than the people themselves. At any rate, the megafauna declined and disappeared shortly after these big-game hunters appeared on the scene. But even in Clovis times the population remained very low.

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**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\
**Post date:** [July 7, 2018, 6:22pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/35 "2018-07-07T18:22:44Z")

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> [@iiandyiiii](#):
>
> What are the biggest questions remaining about humanity’s recent evolution and interaction with other homo genus species?

Just to be clear, you are focusing only on the happenings since the emergence of our species, right? We used to say that happened about 200k years ago, but recent evidence is pushing that date back further, to maybe around 300k years ago.

In that case, I would say the biggest question revolves around language. Personally, I think language predates our species, but many biologists still think that “fully articulate language” did not emerge until around 100k years ago. We will resolve this as soon as we clone a Neanderthal and see how well he or she can converse with us. 😉

Another one would be the behavioral differences between us and Neanderthals, especially in the intellectual capacity area. More and more evidence seems to be arising that breaks down the barriers between the two species, but it’s just so difficult to tease out definitive answers from the fossil record.

> [@](#):
>
> I’m sure there are lots of others. I find this to be one of the most fascinating subjects in modern science.

Me, too. I’ve been fascinated by evolution, and human evolution in particular, since I was about 12.

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**Author:** ![septimus](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/septimus/32/410_2.png) [@septimus](https://boards.straightdope.com/u/septimus)\
**Post date:** [July 7, 2018, 7:04pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/36 "2018-07-07T19:04:14Z")

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Regarding the date of human arrival in the Americas:  
[The MRCA of the Q-M1107 Y-chromosome clade is dated to 16,200 BP ± 1100](https://www.yfull.com/tree/Q-M1107/). This is the clade associated with the “Amerindian migration.” (Na-Dene tribes like Navajo have a different Y-chromosome.)

Interestingly, there is a subclade (L804) of Q-M1107 with MRCA dated to 3200 BP ± 500 which is found today in Sweden, Norway and Britain. (Look under M930 about 1/5 the way down above-linked page.) How did these Amerindians get to Northern Europe? :eek: Did Bronze Age Scandinavian sailors visit America and bring slaves home??! (Be careful: there is also a completely different subclade of Q also found in Scandinavia.)

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**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\
**Post date:** [July 7, 2018, 7:45pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/37 "2018-07-07T19:45:50Z")

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I don’t expect the earliest humans to have been clearing forests and setting up plantations or large farms. But the evidence for Clovis as mentioned is very widespread. Stone tools go back hundreds of thousands of years and can be found widely all over Africa and Eurasia where stones are appropriate. Why wouldn’t an appreciable tribe of humans who made it as far as Pennsylvania not be populating enough to leave as many traces as Clovis did 10,000 years later? Especially if they made it to Monte Verde also? That was my point. Everywhere humans went, they multiplied and populated, eventually to the carrying capacity of the land (for their lifestyle). Why would the 23,000 year old Americans be the exception? Particularly, having made it across the Bering tundra, they had proven their survivalist skills. To me, that’s the biggest question regarding the date the Americas were settled.

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**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\
**Post date:** [July 7, 2018, 7:50pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/38 "2018-07-07T19:50:31Z")

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> [@RaftPeople](#):
>
> A few random thoughts:  
> Following that line of thinking, it seems that social animals would tend to have greater intelligence. Are there any counters to that?
> 
> It also seems like non-social animals have some intelligence, so maybe there is a base amount that allows for effectively finding food and avoiding predators, but advanced levels don’t help?
> 
> What about an Octopus, is social?

There are many species of social insects that have extremely complex communal behavior, while having pretty much no individual ‘intelligence’ at all. The complex social behavior emerges from millions of individuals operating under simple instinctive rules.

Which brings me to what I think is the most important and ongoing understanding of human evolution - just how complex human society is and how much our well being derives from emergent properties of group behavior. We think we know a lot more about why humans do what they do than we really can know.

Complexity and information theory are changing the way we few ecosystems, including human social ecosystems.

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**Author:** ![MandaJo](https://avatars.discourse-cdn.com/v4/letter/m/ac91a4/32.png) [@MandaJo](https://boards.straightdope.com/u/MandaJo)\
**Post date:** [July 7, 2018, 8:41pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/39 "2018-07-07T20:41:58Z")

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> [@md2000](#):
>
> I don’t expect the earliest humans to have been clearing forests and setting up plantations or large farms. But the evidence for Clovis as mentioned is very widespread. Stone tools go back hundreds of thousands of years and can be found widely all over Africa and Eurasia where stones are appropriate. Why wouldn’t an appreciable tribe of humans who made it as far as Pennsylvania not be populating enough to leave as many traces as Clovis did 10,000 years later? Especially if they made it to Monte Verde also? That was my point. Everywhere humans went, they multiplied and populated, eventually to the carrying capacity of the land (for their lifestyle). Why would the 23,000 year old Americans be the exception? Particularly, having made it across the Bering tundra, they had proven their survivalist skills. To me, that’s the biggest question regarding the date the Americas were settled.

One theory I’ve heard is that they were focused on the coasts, and when sea levels rose much of the evidence was covered up. When big-game hunting technology rose, it spread very quickly and people moved inland.

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**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\
**Post date:** [July 7, 2018, 11:23pm UTC](https://boards.straightdope.com/t/what-are-the-biggest-questions-remaining-in-the-study-of-recent-human-evolution/817155/40 "2018-07-07T23:23:00Z")

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There’s a number of examples of Pre-Clovis sites, but for years the Clovis First orthodoxers cast extreme doubts about them. They basically required an almost impossible level of evidence to accept anything dated before Clovis. So for a long time, they weren’t accepted by most archeologists.

Examples of Pre-Clovis sites are [Page-Ladson](https://en.wikipedia.org/wiki/Page-Ladson_prehistory_site) in Florida, [Cactus Hill](https://en.wikipedia.org/wiki/Cactus_Hill) in Virginia, and the [Buttermilk Creek Complex](https://en.wikipedia.org/wiki/Buttermilk_Creek_Complex) in Texas.  
BTW, when I asked about the Bluefish Caves site above, I meant specifically the 25,000 BP date. Is that date widely accepted by other archeologists? I found some pages online where scientists had doubts.

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