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Humans Interbred with Four Extinct Hominin Species, Research Finds

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Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#141

"Homo sapiens" is Latin for "wise man," but there were many Hominin species who possessed comparative culture, art, and intelligence. Neanderthals actually had larger brains compared to modern humans[0]. There are many theories on why Neanderthals became extinct[1]; my favorite is that we simply outbred them because of our sex appeal. What is Latin for "sexy human?" [0] https://en.wikipedia.org/wiki/Neanderthal#Anato…

"Lorem Homines" is Google's take.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#142
post #58

"Homo sapiens" is Latin for "wise man," but there were many Hominin species who possessed comparative culture, art, and intelligence. Neanderthals actually had larger brains compared to modern humans[0]. There are many theories on why Neanderthals became extinct[1]; my favorite is that we simply outbred them because of our sex appeal. What is Latin for "sexy human?" [0] https://en.wikipedia.org/wiki/Neanderthal#Anato…

They had greater cranial capacity than us, but so do elephants and whales. And the animal with the greatest brain-to-body-size ratio is tree shrew, suggesting that size doesn't really matter when it comes to intelligence.

One argument I've seen frequently is that humans offset our smaller crania by losing the sloping foreheads of earlier hominids.

Neuron count in the cerebral cortex seems to predict intelligence better than total neuron count (e.g. putting humans ahead of elephants, and chimps ahead of giraffes), with only one odd case (pilot whales) beating humans. So if we lost overall capacity but retained most or all of our cerebral cortex size, the change might be explained.

(Full disclosure: a quick look says most primate brains are right near 26% cerebral cortex, while humans are around 18%. It's possible intermediate hominids were even lower, but without knowing why the difference exists I can hardly assert that.)

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#143

Earlier quoted context omitted.

That is exactly what they did - all the Neanderthal genes in the current populations has come down via Neanderthal males and sapien female matings. Personally I blame Tinder, but it could have something to do with Haldane's Rule [0]. 0 https://en.m.wikipedia.org/wiki/Haldane%27s_rule

If a human male and a neanderthal female mated and produced female offspring, who then also reproduced, etc., how could you later tell that it was a human female and a neanderthal male? As far as I can understand, all we can speculate about is the sex of the offspring who reproduced, not the original pairings, correct?

Theoretically mitochondrial DNA (which is maternal-only) could do the trick.

In practice I don't think we have the sort of baseline sample it would take to work out which mitochondrial genes are neanderthal-derived. I suppose it might be possible to rebuild that list by looking at high-admixture populations and seeing where their mitochondrial DNA differs, then use that aggregate to compare an individual's mDNA to their DNA and see if it's is "more Neanderthal" (i.e. female line) or "more Sapiens" (i.e. male line)?

But realistically, I'm betting the answer is "admixture happened a bunch of times in a row, with different hominid groups in different places, even if there was a gender skew it's a mess that's impossible to discern".

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#144
post #128

Earlier quoted context omitted.

The earliest homo sapien skeletons were found in Morocco and are dated almost 300,000 years old. So our species was around for hundreds of thousands of years and we didn’t do much more than the Neanderthals. So Neanderthals not demonstrating culture doesn’t mean much, since our own species also went a long time without demonstrating culture. Indeed, it is an interesting question , what were we using these enormous br…

Looking for the monoliths? Jokes aside, probably not much. Biological classifications don't imply sameness. You don't get anatomically modern humans until 30,000-50,000 years ago. Even that doesn't tell you much about cognitive ability. Think about something like the Flynn Effect [1]. In the past century real IQ scores rose by more than a standard deviation throughout most of the world. That means a person of perfect…

This is a bizarre thing to write:

"You don't get anatomically modern humans until 30,000-50,000 years ago."

And this is wild speculation without any basis:

"And so the only justifiable explanation is that we probably didn't have that much going on upstairs until relatively recently."

Economic development is complex, it depends on a lot more than IQ. As a point of comparison, we could ask why did the Industrial Revolution only happened 200 years ago? If, as you suggest, homo sapiens have had high IQ for 50,000 years, then why didn't we have the Industrial Revolution much sooner?

But more so, you seem to imply, in response to the original article, that the mixing of homo species helped us develop a certain kind of IQ. But according to that theory, the most advanced people on Earth should be the aborigines of Australia, as they were the first group to mix with all the different homo species, as sapiens moved from Africa to Australia. But in fact, the aborigines of Australia were quite content with their lives, and felt no need to build civilizations, even though they certainly have high IQ, and they have the mix of genes you'd expect of humans outside of Africa.

About this:

"What triggered the intellectual spike?"

There was no spike in IQ. You have no reason to believe that. The development of culture and civilization have nothing to do with IQ. Large parts of the world remained completely primitive until recent centuries, even though those regions were full of high IQ homo sapiens.

I can't tell if you are trying to build a racial theory of history, but if you are, that idea has been debunked many times. All I can do is recommend that you read some of that debunking.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#145

So its possible that modern races of humans are actually our archaic ancestors?

yes, I am hoping specific gene contributions from specific archaic humans will eventually be used to determine the ethnicity or race of a person. this will lead to better health outcomes as it's well known that drugs do not affect people of different races/gender the same. the push back from doing this probably comes from groups that are trying to hide past genocidal events.

Possibilities outside our comfort zones but comfort should never influence our search for truth.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#146
post #114
post #3

If we interbred with them, how are they actually species? It seems more to me you're talking more about racial or breed differences akin to breeds of dogs if two species actually successfuly had viable offspring in the wild.

Yes. A topic of much debate. Many of the original work regarding Neaderthals was by 19th-century elite-school scientists with a publication history of eugenics and the confidence that comes from the knowledge of innate superiority of their own kind. Anyone who didn't look like them would be obviously inferior. They didn't know what we know today -- Neanderthals were light-skinned fair-hared people who had survived fo…

> That there are light-skinned fair-haired Europeans today is evidence that they didn't vanish completely.

This article suggests otherwise: https://www.newscientist.com/article/dn22308-europeans-did-n...

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#147
post #116

Earlier quoted context omitted.

I never had the chance to meet elephants. Now, from what I've learned/read about their behaviours, I have no doubt on the depth of their lives. https://en.wikipedia.org/wiki/Elephant_cognition#Elephant_so... And I wouldn't call that "some sort of language". That's language. Species-specific. Not "human" language. Even language that another species can grasp more or less perfectly. You can get that with minimal observ…

When I see a videos / images of wolves I don’t perceive that “intelligence” that I perceive from dogs. Not to say wolves are any less intelligent or cognitive, dogs just have had the constraint that they needed to be able to communicate with humans well or they could die. Kind of makes me think if we ever were to encounter extraterrestrial intelligence we might have trouble identifying them as intelligent, or, have t…

Fun fact: Dogs developed whole extra sets of facial muscles during their domestication: https://www.theatlantic.com/science/archive/2019/06/domestic...

This happened in a remarkably short period of time, and the running theory is that early dogs with more expressiveness were better cared for and received by human societies than similar dogs that were less expressive.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#148
post #96

Earlier quoted context omitted.

Neither of those animals has the appropriate morphology to build tools or use complex language. How do we know they aren't actually smarter than us?

You are asking me to prove that humans are smarter than elephants? It makes for an interesting philosophical debate, but that is all it really will be. Kind of like me asking you to prove you are smarter than a rock, or that you are really conscious.

Elephants' computational machinery look almost exactly like ours, except much larger. I can measure the thermodynamic properties of any rock's machinery and conclude with certainty it has no familiar intelligence. The only thing elephants have against them is they don't have technological civilization and just sort of bumble around, but so did Socrates. To me it remains an open question.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#149
> “For example, all present-day populations show about 2% of Neanderthal ancestry which means that Neanderthal mixing with the ancestors of modern humans occurred soon after they left Africa, probably around 50,000 to 55,000 years ago somewhere in the Middle East.”

I gotta wonder what people are thinking when they write this stuff. I mean, "Neanderthal mixing with the ancestors of modern humans occurred soon after they left Africa". Do they imply that those whose ancestors never left Africa are not "modern humans"? I doubt it. So they're just being sloppy.

Re: Humans Interbred with Four Extinct Hominin Species, Research Finds

#150

Earlier quoted context omitted.

If a human male and a neanderthal female mated and produced female offspring, who then also reproduced, etc., how could you later tell that it was a human female and a neanderthal male? As far as I can understand, all we can speculate about is the sex of the offspring who reproduced, not the original pairings, correct?

Theoretically mitochondrial DNA (which is maternal-only) could do the trick. In practice I don't think we have the sort of baseline sample it would take to work out which mitochondrial genes are neanderthal-derived. I suppose it might be possible to rebuild that list by looking at high-admixture populations and seeing where their mitochondrial DNA differs, then use that aggregate to compare an individual's mDNA to th…

> Theoretically mitochondrial DNA (which is maternal-only) could do the trick.

That is, sperm have just one mitochondrion, and they almost always dump it as part of fertilization.

But not always, so there is nonzero male contribution of mitochondrial genes.

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