Neanderthals, modern humans may have co-existed in Europe for at least 10k years | Hacker News Reader

Neanderthals, modern humans may have co-existed in Europe for at least 10k years

theconversation.com

49 pointsrntn68 comments

I once watched a documentary where it was mentioned that homo sapiens co-existend with around 20 archaic human forms (Homo erectus, Homo floresiensis ...etc) , of which only homo sapiens survived and thrived.

But this is a subject that always scared me especially with nowadays' politics.

During the period for which we have evidence, Neanderthals seem to have had smaller populations than Homo sapiens, and they reproduced more slowly (longer gestation plus longer interval between pregnancies). So it may be that they went extinct for those reasons.

That may be so .. but I recall reading about Neanderthals' cave drawing .. they depicted Homo sapiens as frightening creatures.

I can’t find anything about neanderthal cave art that represented Homo sapiens.

They also had a lower brain to body ratio so weren't as intelligent.

Their ratio was about the same as homo sapiens. It's not clear that they were less intelligent, they seem to have had a similar degree of intelligence based on findings from caves in Spain.

About the same but significantly lower. Neanderthal cave art is basically scribbles and scratches compared to say Altamira.

Why is brain:body ratio correlated with intelligence?

It’s pretty much the one metric that holds true across all animal species. Read about EQ (encephalization quotient)

What's so scary about it

If I were to hazard a guess, it would be that the species line is somewhat subjective. If you slide broader than today’s definition then we had a lot of human genocide in our collective past. If you slide narrower than today’s definition then we could end up with a lot of human genocide (by today’s definition) in our collective future. Anything to do with genocide is rather scary.

In the 50s, it was thought that we were smarter than them and killed them all off (the author of Lord of the Flies even wrote a book on this).

This seemed to inform futurists at the time thinking about what it would one day look like if there was something smarter than humans.

Hopefully we do a better job at considering this revision to our picture of the past and correcting our anchoring bias in our estimation of such a future.

It's not known for sure why they went extinct and the extent of their cognitive abilities. It's also only one example. Another might be Europeans coming to the Americas (with more deadly technology and infections diseases, not smarter). Or humans being super predators. We don't know what advanced alien life would be like. Or what AI might become. There's lots of possibilities. Sagan's Contact and The Culture are on on one end, with The Dark Forest and Skynet being on the other.

I wonder how much both the early 20th century and the current postmodern views on relations with the Neanderthals was influenced by the politics of the times. Back then people wanted justifications for colonialism and promoted social Darwinism; now we’re looking to promote multiculturalism and global trade. Both ways we’re projecting onto the prehistoric past what we want to see there.

Well we don’t know that they were smarter than us. The EQ (brain to body ratio) of homo sapiens is 0.019 and Neanderthals was 0.017. They were probably considerably stupider.

> They were probably considerably stupider.

What makes you say that?

[dupe]

Discussion: https://news.ycombinator.com/item?id=39215750

I saw a documentary on humans and Neanderthals about a decade ago and it melted my mind. Absolutely fascinating that there was another species that was very similar to us that we interbred with. Crazy!

I kind of feel the opposite: the crazy part isn’t that we had relatives, but that we’re the only remaining species of the Homo genus.

It’s somehow unsettling that we are the only ones left. Most large mammals come from a genus with many cousins. We’re alone either because we killed the others, or because intelligence actually has a hard time surviving in nature. Neither is really good news for us.

The taxonomy of archaic humans is debatable to say the least so "we are only the ones left" may just be an artifact of 19th century anthropology and prestige chasing. Realistically the genetic variation between the average human and Neanderthals is only about twice the variation within the modern human gene pool. Compared to our nearest primate at 10-50x the difference depending on how you measure.

Given the number of genetic bottlenecks we have evidence of in our past, we may all be the same species and the modern human is just the last surviving group of inbred Homos.

Isn’t “genetic bottlenecks” another way of saying that intelligence has a poor track record of surviving?

Not really - genetic bottlenecks aren't a feature of intelligent animals, it's a feature of a population that's undergone some kind of very dramatic pressure event like catastrophic loss of habitat or mass illness.

Bottlenecks are more likely to be an issue for species with a limited range, population and a slim range of survivable conditions. Intelligence has a way of expanding those ranges by making you more equipped to access otherwise inaccessible resources. Think of elephants navigating between watering holes during droughts, crows using tools to fish out hard to get food, or orcas using sophisticated hunting techniques to get at prey they otherwise could not.

Intelligence adds flexibility, and flexibility is especially useful under pressure.

which implies that there are humans alive that are genetically as far apart from each other as the average human was from the average neanderthal (i.e. statistically there probably exists humans who's separation from each other is twice the average distance).

> or because intelligence actually has a hard time surviving in nature.

Alas, I can't find it now... there was a book that I read (Bear / Brin / Benford as the author I believe... maybe Baxter... one of the great Bs I'm sure of) about the matrilineal line from a small shrew like animal in the time of the dinosaurs through neanderthals to modern times... and beyond.

Part of the "and beyond" was the theme that intelligence and our brain is an extremely expensive organ to maintain (our brain consumes about 20% of the calories that we consume a day https://www.ncbi.nlm.nih.gov/pmc/articles/PMC124895/ ). After some catastrophe that reduces the energy budget that animals can use... well, intelligence is one of the things to go.

(Late edit: It was Baxter - https://en.wikipedia.org/wiki/Evolution_(Baxter_novel) )

I think that any forecasts are probably reading too much into a limited data set.

Intelligence does have an incredibly hard time surviving in nature. Humans are hyper-optimized for it. We are far weaker than chimps, and burn 30% more calories. We are slow reproducing k-strategists, with infants that are helpless for years.

That said, Humans are planet level apex predators, and universal omnivores that consume everything whales to yeast and synthetic foods made from elemental materials.

Over the course of our existence, our capability for growth has vastly overshadowed any downside from intra-species hostility. We are also the most cooperative and social animal that has ever existed.

This is a pretty strong position to be in, and certainly better than just about any other animal sharing the plant.

Yeah what blows my mind thinking about it is just how we are the only species that communicates across continents.

Or may be because we lived together for so long that individual differences disappeared and averaged out as people intermarried and had a lot of mixed babies.

I'm not saying that this necessarily happened, only that the burden of proof for your theory should be higher.

This is what happened, logically speaking. Though not averaged out in a balanced manner: instead, to the degree that Neanderthal genetics comprise anyone's genome.

Not to say that there weren't interspecies genocides, but we interbred with them and then outcompeted, for resources, the pure species into extinction generally speaking. Which was inevitable, parallel to how homo sapien lineages also die out from simply being outcompeted.

It is likely that the Neanderthal genome was outcompeted down to a percentage at which it was and is competitive. 50-50% Neanderthal-Modern Human? No dice, Darwin. It had to be reduced to a few percentage points, at which point individuals started being competitive. Was the last pure Neanderthal pair murdered, did they die from starvation, or did they just refuse to have kids? It could have been any of those, but the general procedure was likely defined by resource competition.

And Neanderthal isn't the only alien-homo genome mixed with that of modern humans.

Were Neanderthals more genetically different from typical Homo sapiens than modern day pygmy peoples? Iirc, Khosians also diverged genetically from other regional peoples.

they weren't necessarily killed off, rather blended into the human population through conquest and wife-stealing and the resulting interbreeding.

indeed, wife-stealing appears to be a very successful formation over long periods of time.. woe to the peaceful

If anything it was the opposite:

> No evidence of Neanderthal mitochondrial DNA has been found in modern humans.[30][31][32]

> This suggests that successful Neanderthal admixture happened in pairings with Neanderthal males and modern human females

Of course it also might mean that human males and Neanderthal females can’t produce viable offspring

It doesn't follow that if human males stole Neanderthal wives sometime in the past, that you would necessarily see Neanderthal mitochondrial DNA in present populations.

Consider a serial 'wife-stealing' human culture. One generation of human males leaps upon a small population of Neanderthals, killing the men and stealing the women. The next generation, a new group of half-neanderthal males leaves the colony in search of wives, finds a human group, kills the men, and steals the women. The children of this generation will be 1/4 Neanderthal with no Neanderthal mitochondrial DNA. Imagine that the first colony gets wiped out, as most ancient communities were. There you go.

> There you go.

So either it didn’t happen at all or if it did it happened in on a much smaller scale than the opposite (Neanderthal male and human female)?

Also this scenario is completely unsubstantiated conjecture so hardly worth discussing.

It probably went both ways to some extent. But the Neanderthal population was much smaller, and probably martially weaker, as they were clearly playing a losing evolutionary strategy.

another interesting fact is that modern Europeans are descended from 4 distinct populations which were as genetically distant from each other as modern Europeans are from Asians: Western hunter gatherers, anatolian farmers, eastern hunter gatherers, and eurasian steppe herders. David Reich goes into it in his book 'Who we are and why we got here'.

> another species that was very similar to us that we interbred with

Ok, if it is so similar to us and we interbred with it, then why is this so special? Might as well call it the same species by stretching the definition a little.

We were only "separate" species because for a period of tens of thousands of years we did not interbreed and developed independently due to physical separation. But we could and did interbreed when the physical separation was crossed. Despite the separation, we remained similar enough genetically that interbreeding was possible.

Were there a higher number of miscarriages than between 2 humans? We will probably never know.

Fascinating question

That is one of the issues with species as a concept. There are quite a few differing definitions which are all useful. It’s typically discussed as the ‘species problem’.

Yeah, the interbreeding must have been uncommon as otherwise over 10,000 years there wouldn't be any meaningful distinction (I assume).

Either uncommon or many of the attempts were unsuccessful.

Alternatively, it could have been so common that Neanderthals were fully assimilated far more rapidly than could be preserved in the fossil record.

Especially that limited part of the record that has been so far revealed.

Don't forget that we intermixed with the Denisovans too.

Based on modern DNA patterns there also seems to have been at least one other major population group around the same time that we have not found any remains of, which was related to both Sapiens and Denisovans.

They probably lived mostly around southeast Asia. (Neanderthals were mostly in Europe and Denisovans are thought probably to have generally inhabited northern Asia).

I can highly recommend The World Before Us by Tom Higham, it goes into the history of the archaeology and science and also goes over a pretty up-to-date understanding of the topic of recent Hominin evolution.

(Also, it's very likely I've misconstrued some of it in my paragraphs above, apologies if so).

> Neanderthals, modern humans may have co-existed in Europe for at least 10k years

We're not all Neanderthals here. I think.

They still do ;)

The origins of the 2 party political system.

IMO it's not that there 'were' multiple species and only we survived; we are still multiple species, but we don't point that out for cultural correctness. Yes, the extent of our differences has narrowed as we passed through survival bottlenecks, but we never became a single species.

If every human can interbreed with every other and product viable, non-sterile offspring, then how could it possibly be that we aren't one species?

To be pedantic about the fuzziness of the "species" delineation, not every human is capable of producing viable, non-sterile offspring (breeding partner notwithstanding).

The fact that some individuals are sterile has nothing whatsoever to do with species delineation. If there were entire pairs of population groups, say the Ainu and the Xhosa, which can no longer produce viable offspring with each other due to generic distance, then we could begin a conversation about speciation of homo sapiens. But there aren't, so we don't.

Do you have anything that will persuade others that we are actually multiple species? I know of no basis for it.

And given no scientific basis (unless I'm wrong), isn't that the reason nobody believes it?

The "cultural correctness" argument seems a rehash of the tired, preconceived argument applied to everything.

Given that there is a single species of human today and most of us have some percentage of Neanderthal DNA, it seems that we are one species today and we were also one species in the past (since we could and did interbreed)

That is tautologically true, considering how Neanderthal is an offshoot of Sapiens.

The question maybe worth asking is just how far they split off, compared to how far we are split off today (or maybe in the pre-modern era, I would expect us to be merging fast since then).

This is complete bullshit. We've sequenced neanderthal DNA and can tell exactly how much modern people have in common.

If you want to promote some scientifically-accurate racism, the only "pure-blooded" homo sapiens come from central and southern Africa, everyone else is just a little bit neanderthal.

Right? Arthur Clarke has a story in which our long lost cousins finally come to rescue us from the shipwreck millennia ago, and offer also to correct the genetic mutation that reduces skin pigment...

Bro science at its peak.

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