Comment by lifeisstillgood | Hacker News Reader

Comment by lifeisstillgood | Hacker News Reader

lifeisstillgood

I have a mental model of how humans spread across the world, something like - many years ago there were several species of upright apes in Africa, (much like there are species of big cats now). These started to move out of Africa as climate and other pressures / opportunities presented them selves. About 200,000 years ago one species (modern humans) joined the others and we fucked up the rest of them so bad they all were wiped out wherever we went. Probably all the species had flint knapping, and fire tools and also had clothes from around 100,000 years ago.

I am not clear where I get that model from - science journalism mostly.

Just that story rocks me back on my heels every time I walk it through.

But I am wondering if it is "supported by the evidence" or not or if discoveries like this blow through that basic sort of model (apart from timings which I see as important scientifically but not directionally - ie Ptolemy and Erastothenes thought the world was round but different circumference - important but directionally the same)

Finally - The awfulness of the web page layout and pop ups. I am slowly finding I can only use "Page Reader" on ios. It might just be old and grumpy name but it seems to be getting worse

The answer is always going to be “it’s complicated.” Your mental model is vaguely correct but hinges on a lot of semantics and nuance - the timing does actually matter to get a full appreciation.

The oldest evidence* of modern humans (Homo sapiens) is about 300,000 years old. “Archaic humans” generally refers to a group that includes neanderthals and some other species, the oldest evidence being maybe half a million years old. First evidence of fire use is over a million years old. The first stone tools are over three million years old and predate the Homo family of species altogether. However the point where our ancestors diverged from chimpanzees was over eight million years ago so “primitive humans” if you will have a very long history.

In that time, primitive humans spread everywhere in the old world. Earliest evidence of tool use in Indonesia, for example, is on the order of 1.8 million years old. At that point the world was in the middle of an ice age and sea levels were much lower so Indonesia was part of the supercontinent and not an island. The oldest evidence of migration to colder climates is 800,000 years old. Our ancestors had already colonized the Old world several times over by the time “humans” left Africa.

It really depends on where you draw the line between “humans” and “hairless monkeys”

* Archaeological evidence survives and is discovered completely by random chance so we could be off by hundreds of thousands of years without straining credulity

> It really depends on where you draw the line between “humans” and “hairless monkeys”

"hairless apes" -- we diverged from monkeys around 20 MYA.

I didn't.

> About 200,000 years ago one species (modern humans) joined the others and we fucked up the rest of them so bad they all were wiped out wherever we went.

I believe that the genetic adaptations to high altitude found on the Tibetan plateau are thought to be older than 200,000 years, the result of modern humans arriving and interbreeding with local homo erectus.

https://www.science.org/content/article/tibetans-inherited-h...

There are a lot of things like this popping up in genetics research these days.

I don't know why people in general hold so tightly onto this notion that humans are 200k-300k years old. It's very obvious from the evidence that humans have been around for ~2 million years and that around 200k-300k years ago a set of genes were selected for that were quite good at spreading around the entire human world (while still maintaining a significant degree of admixture with humans who were already there).

It's honestly kind of insulting. It would be like if people looked at the genetics of Australia, discovered that there were no "pureblood" aboriginals anymore and declared that humans arrived on the continent with James Cook. Not only would it be factually incorrect, but it would deeply bias any possible study of australian aboriginal life.

Its really impossible to go back in history, at all. Its pretty much impossible to agree about what is going on in the present.

Scientists, historians, everyone really attempts to show how they deal in facts, ones which mere mortals should just accept, but when you dig into any area, you will realise that its all highly ambiguous, whether that's the facts that are being presented, the way its presented, the money trail, the way it is framed, etc.

People disparage 'anecdotal experience' but to me its all any of us has. Its our 'golden source'. Whenever we start undertaking actions that are not coherent with our personal, lived experience, we are walking on thin ice.

> Its really impossible to go back in history, at all

Sequencing ancient DNA allows us to do this in some respects. We’ve learned a lot in the last <10 years about population movements, relations, and timing from this. See “Who We Are and How We Got Here” by David Reich. Main takeaway: there was a lot more mixing of early modern human population groups than anyone expected.

> Its really impossible to go back in history, at all.

That sounds quite defeatist.

I expect that linguistic, archaeological, logistical, genetic, and probably a few other vectors, can lead us to at least a sequence (causation) view of history we can have some confidence in, and then perhaps we can debate the precise dates.

> Its pretty much impossible to agree about what is going on in the present.

That sounds like a mantra posited by people trying to claim truth is subjective, and/or that a particular narrative (unsupported by evidence) is 'going on'.

I prefer to believe that an objective assessment of reality (as it stands) is not beyond our capabilities.

> That sounds quite defeatist.

Far from it. In our own countries, the freedom fighting good guys always win. It was the baddies that lost.

> That sounds like a mantra posited by people trying to claim truth is subjective, and/or that a particular narrative (unsupported by evidence) is 'going on'.

I think truth is objective. But no one individual, or group of people, has truth - they just have an interpretation. I actually think this is fairly obvious too.

Feel free to give an example of an objective assessment of reality.

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