A Human Paradox

[Berzerker]

Something's been nagging me... a question, one that needs answering. There's no stopping "us", we left Africa and absorbed or conquered earlier peoples who had left Africa before us. We've reached the ends of the world and now we're headed for the stars. Its in our blood... Why did it take us so long to leave Africa?

I saw an article discussing how cancer spreads or becomes metastatic, something about the original tumor changes - density. As cancer cells multiply they need room to live, the tumor tries to tap into the local resources but eventually there are too many cells and they head for new homes, just like life in general.

Is that the answer? We lived in Africa for ~ 200,000 years but we didn't leave for 100,000 years or more. Something aint right, what were we doing for >100,000 years in Africa and why didn't we leave long before?

https://en.wikipedia.org/wiki/Recent_African_origin_of_modern_humans

 

[Narz]

There probably was plenty of room, nice climate for humans for 100,000 years. Why go wander off to some cold unknown place?

As for humans "headed for the stars" I don't see any evidence of that happening. It's anybody's guess whether we'll even reach the nearest planet, reaching another star-system is highly unlikely (maybe some sort of AI will someday if humans survive long enough to invent it).

 

[FriendlyFire]

Something aint right, what were we doing for >100,000 years in Africa and why didn't we leave long before?

Maybe you should have built that settlement on the first turn and started researching straight away instead of wandering around ?
Humanity was probably "evolving" during that time period.

 

[Berzerker]

There probably was plenty of room, nice climate for humans for 100,000 years. Why go wander off to some cold unknown place?

As for humans "headed for the stars" I don't see any evidence of that happening. It's anybody's guess whether we'll even reach the nearest planet, reaching another star-system is highly unlikely (maybe some sort of AI will someday if humans survive long enough to invent it).

it was a figure of speech

 

[Birdjaguar]

People respond to their needs. In human communities needs are often driven by the size of the community. Small communities with lots of food and water nearby have little need to move about. also if they followed migrating animals to sustain themselves, maybe those animals didn't migrate out of Africa, but went south or west rather than east and north. I would guess that two things finally "pushed" those folks out: increased population and changing climate.

 

[Valka D'Ur]

There probably was plenty of room, nice climate for humans for 100,000 years. Why go wander off to some cold unknown place?

As for humans "headed for the stars" I don't see any evidence of that happening. It's anybody's guess whether we'll even reach the nearest planet, reaching another star-system is highly unlikely (maybe some sort of AI will someday if humans survive long enough to invent it).

The Voyager probes are on their way. They haven't reached the Oort Cloud yet, but they're quite a long way from home. Thing is, though, it's going to take at least 40,000 years to get anywhere near to any star we know of... and they're not even aiming for there.

So that scene in Star Trek V in which the Klingon shoots one of the Voyager probes for target practice (a scene that was supposedly funny, but which I think is utterly disgusting) thankfully can't happen.

Maybe you should have built that settlement on the first turn and started researching straight away instead of wandering around ?
Humanity was probably "evolving" during that time period.

I always build my first settlement on the first turn, unless it's got too many unusable squares nearby or has little or no access to water. I do try to build by the second turn, though.

 

[Bugfatty300]

Africa was really really really big and hard to get around until Mercador fixed it.
Africa was surrounded by oceans except for tiny land bridge at Sinai and possibly others in Yemen and Gibralter.
The land bridges likewise were surrounded by the hostile Sahara desert.
There was no concept of "outside of Africa" so nobody had a desire or motive to leave Africa.
Early humans and primates who did leave Africa did so by chance/accident and never came back to tell the others about all the cool stuff they found.

So that scene in Star Trek V in which the Klingon shoots one of the Voyager probes for target practice (a scene that was supposedly funny, but which I think is utterly disgusting) thankfully can't happen.

That scene always seemed odd seeing as those probes would still be be the Federation's frontyard practically yet here is this Klingon ship just blowing crap up.

 

[Valka D'Ur]

That scene always seemed odd seeing as those probes would still be be the Federation's frontyard practically yet here is this Klingon ship just blowing crap up.

It was considered funny by someone - Shatner, or someone else on the production team, so they put it in. And since that movie had absolutely no credible science, of course nobody listened to anyone who might possibly have pointed out that the Enterprise can't go to the middle of the galaxy in just a few hours, there's no planet there (we knew even in the '80s/'90s that there's a massive black hole there), and the Voyager probes are still going to be basically in our solar system's neighborhood in 300 years.


Anyway, on-topic... the Sahara region wasn't always desert, so some parts of it would have been a nicer, more congenial place to stay - lots of food, adequate water, shelter... so I think it's a safe assumption that unless issues of lack of food or water, an increasingly hostile climate, or even warfare with other groups also competing for resources happened, the early hominids in Africa wouldn't have had any compelling reason to leave.

Humans are wanderers, yes... but inbetween that wandering, it's nice to have a settled existence where safety, food, water, and shelter are assured. Nowadays, I daresay that most people prefer to stay put unless they have some compelling reason to go somewhere else. Climate change, wars, natural disasters, and economic reasons are why people move around nowadays. They're no longer following the animal herds from one continent to another.

Curiosity did its part, of course... but given the kind of society we have now, curiosity isn't going to be enough to get us off this planet.

 

[Hrothbern]

People respond to their needs. In human communities needs are often driven by the size of the community. Small communities with lots of food and water nearby have little need to move about. also if they followed migrating animals to sustain themselves, maybe those animals didn't migrate out of Africa, but went south or west rather than east and north. I would guess that two things finally "pushed" those folks out: increased population and changing climate.

I tend to think along the same considerations.
What I think as well is that we only thrived at sweet spots, with sweet water, many tubers, many small mammals/seafood available.
During favorable climate environments, under population pressure, spreading out to the next sweet spot.
During unfavorable climate environments dying out except for the tribes at the sweet spots.
Concluding that:
perhaps the distance between sweet spots was less favorable to get out of Africa and reaching for example the sweet spot area of Sumer.

 

[Birdjaguar]

100,000 years is a long time in the human time scale. Once organized into small communities by agriculture, it took us only 5000 years to build cities and other 5000 to build iphones. So for those other 90,000 years we were probably insignificant parts of the landscape where there were other players that dominated both our local area and the region around. I'm guessing we developed our hunting, social and communication skills in that period.

 

[Senethro]

Its important to remember that the rest of the world wasn't empty of people of varying homonid species, and neither was africa. Sometimes the "movement" of anatomically modern humans is migration and sometimes its the spread of associated genes through interbreeding.

https://www.theguardian.com/global/2017/sep/05/the-secret-about-human-evolution-found-in-spit

There was plenty going on, everything just takes a really long time in low density hunter gatherer populations.

 

[Hrothbern]

100,000 years is a long time in the human time scale. Once organized into small communities by agriculture, it took us only 5000 years to build cities and other 5000 to build iphones. So for those other 90,000 years we were probably insignificant parts of the landscape where there were other players that dominated both our local area and the region around. I'm guessing we developed our hunting, social and communication skills in that period.

Hunting leaving some archeological remains, but social and communications skills not (or hardly) making it difficult to track progress over time.
As humans we are also unique in the long childhood time, indicating there was much to learn (like social, communication, childs games (preparing hunting, childs hunting small mammals nearby)). But again hard to see from archeological finds unless we find out where in our DNA this long childhood is triggered and we find relevant and usable DNA covering that 90,000 years.
Speculating further.
We have as of now a reasonable big variety of the wiring of our brain. I can imagine that a tribe with some people having more leadership charisma, some with more social binding, some with more empathy, some with more memory (herbs, medicin), some more stronger/resilient, form together a more succesful tribe. But those "specialists" would only be of advantage in a big enough group in a sweetspot allowing for a certain waste of people with too much of those features and on their own as individual less fit to survive.
We have for example people that get goose bumps from music and people that do not, which can be traced back to higher density and connectivity to certain brain parts, and those belong to bigger empathy and coordination between what we experience and what we feel. We have lots of hard-wired and psychological variety. I simply believe that this was (and is) to our advantage.
I believe that social empathy, binding factors were important. But I believe as well that some members of the small tribe having other wired brains, in the A-spectrum, were also highly contributing as a niche for toolmaking and technical stuff (it looks that this was improved by some Neandertal DNA from interbreeding).
And all this takes time for the many mutations and can only be tracked over that 90,000 years by usable DNA after we learned where all these brain-psychological features are DNA triggered.

Lots to do

 

[Berzerker]

https://www.theguardian.com/science...-to-neanderthal-genomes-over-200000-years-ago

Neanderthals left Africa and may have interbred with a wave of people closely related to us around 400-270 kya

linked from senethro's link

 

[Manfred Belheim]

So.... what's the paradox exactly? Why did humans with no language, civilisation, technology or understanding of the world, not spread as fast as humans with all those things?

 

[innonimatu]

I do suspect that all those neat theories about how humans originates and spread will go through many revisions still. It's anyones guess now but I'd bet on people have mixed plenty of times. There may have never been "human races" in the proper biological term, as far as we know those "ancestors" could have interbred and did so.

 

[Berzerker]

the paradox is we spent ~>100,000 years or more sitting in Africa and took maybe half that to 'conquer' the world

Language and technology didn't exist? People were leaving Africa more than a million years ago

 

[Valka D'Ur]

Hunting leaving some archeological remains, but social and communications skills not (or hardly) making it difficult to track progress over time.

Anthropologists found artifacts in Neanderthal gravesites that suggest there was an awareness of death in the abstract, and there may have been a belief in some sort of afterlife.

We have for example people that get goose bumps from music and people that do not, which can be traced back to higher density and connectivity to certain brain parts, and those belong to bigger empathy and coordination between what we experience and what we feel. We have lots of hard-wired and psychological variety. I simply believe that this was (and is) to our advantage.
I believe that social empathy, binding factors were important. But I believe as well that some members of the small tribe having other wired brains, in the A-spectrum, were also highly contributing as a niche for toolmaking and technical stuff (it looks that this was improved by some Neandertal DNA from interbreeding).

Interesting. I didn't realize there are people who don't get such reactions from particular kinds of music. Do you include those who cry when they hear a piece of music that really touches their emotions?

Why did humans with no language, civilisation, technology or understanding of the world, not spread as fast as humans with all those things?

Try to apply this to a real-world example. Why are there many fewer deaths nowadays due to natural disasters such as floods? It's because humans are able to make plans for hypothetical possibilities (ie. plan how to conduct search & rescue operations and decide where evacuation centres will be before a storm hits) and they're able to communicate this information to everyone else. If nobody knew what was going on, the death toll would be in the thousands or tens of thousands, rather than in the dozens. You can't "spread out" if your particular group of people died from an inability to survive natural disasters or other situations in which communication and planning for the future - being able to imagine a future in the first place, even - are crucial factors.

 

[Birdjaguar]

the paradox is we spent ~>100,000 years or more sitting in Africa and took maybe half that to 'conquer' the world

Language and technology didn't exist? People were leaving Africa more than a million years ago

"Conquering" the world is not all about mobility. It is about population density (fertility?) and minimizing competition (homo erectus?). On top of that geography must cooperate. Ice age climates may have made southern Europe and SW Asia not very suitable for migration and habitation. In fact the earliest migration (~40,000 BCE)was along the south Asian coast from Africa to Australia. This suggests that the land route into the Middle East was less suited to the needs of those modern humans or had too much competition.

Africa is a big place, why do you want to rush humans out of it? They moved when ready and the conditions were right.

 

[Perfection]

Just because there were anatomically modern Homo Sapiens 200kya, doesn't mean they were behaviorally modern (my understand is that occured ~50kya). They may not have had the sort of same cognition that modern humans have thus lacking the competitive edge needed to drive out Homininae species out of the varied biomes of Asia and Europe.

This is based on my limited understanding, I'm not a subject matter expert.

 

[Birdjaguar]

I just found this:

https://www.sciencedaily.com/releases/2017/08/170810104931.htm

Summary:
Humans may have exited out of Africa and arrived in Southeast Asia 20,000 years earlier than previously thought, a new study suggests. Findings also suggest humans could have potentially made the crossing to Australia even earlier than the accepted 60,000 to 65,000 years ago.

This pushes the first exiting from Africa to a much earlier date, but widens the gap between leaving for Australia and settling in the ME.