Absolutely fascinating. I love hearing about Neanderthals and Denisovans and look forward to scientists learning even more in the future. It's mind boggling to think of other sentient species like our own that we could actually interbreed with.
That homo sapiens sapiens most likely displaced them, but that doesn't really mean as much as your comment might intend to insinuate.
Neanderthals lasted half a million years, and the more we learn the more we appraise them as sophisticated. That said, they seem to have faced a caloric challenge in a world with sparse mega fauna.
Based on everything I've read, modern humans pre-language excelled at one specific thing: walking very long distances without exhaustion on less calories. Ends up that's pretty dang useful in spreading across the globe.
That's an interesting idea, that there was essentially a trough to get through before the neolithic revolution and the (relative) caloric abundance it brought.
Maybe it's generally an advantage when it comes to exploration, e.g. finding new places to settle. Or maybe it's specifically an advantage when hunting, as in endurance hunting.
> that doesn't really mean as much as your comment might intend to insinuate.
Mine was an open question. Your speculation about what I might intend to insinuate is perhaps a projection from your own psyche, which you haven't actually articulated, so I can't comment further on it.
If you imagine I was saying something like modern humans were superior to other hominids because they defeated them - I wasn't. In fact, it isn't even true to say species X was defeated by species Y, because the outcome was a merger of (at least) 2 species, not an outright conquest. And as you seem to be saying in your comment, the survival of species is as much about the environment as it is about the qualities of a species.
Your point about modern humans walking long distances efficiently is an interesting one, though I'm not sure how it explains how the world was colonised. Are you picturing some kind of a race to see which species could travel the furthest out of Africa in the shortest time, to plant a flag on America or Asia and claim it for the species?
Wouldn't colonisation have taken place more gradually?
Assuming humans have to exist socially, in contiguous communities rather than solo, generation by generation, human populations would have progressively acquired more land (along the coast, say) by acquiring territory adjacent to their base. This equates to travel in the order of say 100 metres per generation - enough to support new housing and food supply for a population increase of a few percent. The success of this endeavour might depend on inter species competitiveness to a degree, and it would also be limited by genetic adaptability to climate variation as the distances added up over millennia, particularly latitudinally.
I did not interpret the open question by /u/wombatmobile the way you and the other poster did. It is not clear from the text that one should do so.
It is not conductive to a discussion to err on the side of malice when in doubt. It is better to clarify and/or to assume the other poster wants to foster discussion.
Well, it’s a fraught question because there is so little evidence to go on. So yes, it’s just an opportunity to speculate - something best done with good faith and an open mind.
But what if there was more evidence? Well there could be if we were willing to instantiate a Neanderthal genome in vivo…
No need for hostility either way, I think my comment was pretty gentle in pushing back on something I said "might" be a perception.
So our ability to walk long distances in moderate to high temperatures is what allowed us to thrive on the plains vs jungles of Africa, before we were modern humans.
As far as modern humans go, it wasn't a single wave of migration, or even multiple waves of migration. The more we learn the more we realize it was more like diffusion of increasingly advanced culture across a mesh that pre-existed across the globe.
Our distance endurance was literally useful for traveling to new and better places as hunter gatherers, or simply following seasons. But it also enabled very specific tactics like persistence hunting or steering entire herds into human designed funnel traps. Near as I can tell from reading these were pretty key to our rise at a critical time.
Then of course, language and the accumulation of knowledge it enables was the huge jump to modernity. We'd like to think we're far past that jump but we really aren't, we've just gotten so good at cracking rocks against each other now they're on the cusp of thinking the same way we do.
Homo Sapiens left Africa in several waves after 250,000 BC and every single wave went extinct till about 60,000 years ago. The question isn't "Why did Neanderthals go extinct?" but "Why did every species of human repeatedly go extinct outside of Africa?" And that needs to be balanced against the nuance that Neanderthals survived at least 600,000 years, straight through the period when Sapiens were recuringly going extinct. So this is a very complex story that we're looking at.
And that makes me wonder whether attribution of the Bruniquel Cave to Neanderthals is justified. I haven't seen any mention of Neanderthal remains found there; the only evidence seems to be the age of a burnt bear bone, carbon-dated to 47,600 years ago. This was back in the 90s [1], when Sapiens were not thought to have reached Europe until later. We know better now [2].
Maybe those original Home Sapiens migrants just went to Neanderthal territory, maybe established "homo sapiens republics" (different culture, technological practices), and eventually got absorbed into the lasting main Neanderthal culture.
Just like it happens to migrants in our time, in just a few years, not thousands.
It could be that after 600.000 years, Neanderthals got somehow behind minimal species fitness required to endure lasting species survival, and they were - this time - absorbed by the Homo Sapiens.
I don't think there weren't ancient / primitive civilizations or tribes, it's just that they were fully erased from history as they didn't left any written history or well constructed monuments and/or big cities that we could find after 100-150.000 years (no need of "great events" to erase cities, just build the houses with mud bricks, wait 30-40k years).
At looking for clues about why those initial waves went exting, maybe we could take a look at how more recent tribes or even old civilizations like Incas, Mayas, etc. made it through a couple of centuries, and eventually got "extint".
Some of those groups were surrounded by other tribes, and tried to expand their territories, with different outcomes.
Some didn't tried to expand, they just got well adjusted to their original territory and didn't need more resources.
But everyone in those groups eventually disappeared from history.
Even when the american continent was discovered, the remaining "true" mayas didn't remembered or indicated that those big monuments, cities ever existed already taken / hidden by the jungle. Many of those also, were just found literally hundreds of years after having seen the last true mayas.