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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

#111

Post by animal531 »

hashberry wrote: post #55

"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…

My favourite comes from archeological evidence showing that we traveled further and traded for a larger range of items, whereas they stuck to themselves and smaller area ranges.

When the cold hit they ran out of options and resources quicker, they simply didn't have the required knowledge of how to survive.

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

#112

Post by ajross »

flukus wrote: post #63
ajross wrote: post #34

Earlier quoted context omitted.

Genes tend to to accumulate mutations at a constant rate (lots of caveats here, but that's the general idea). If you find that a population has a family of gene variants that are very different from the same ones in another population, then it's a good bet it arrived from external breeding. And the relative differences between the modern descendant genes can tell you when it happened. Again, I'm sure the real models…

How do they differentiate multiple parallel lines lines of mutations coming back together from a separate subspecies existing for much longer?

Genes don't "come back together". If you have a given gene, it's a direct descendant from exactly one of your ancestors in each generation.

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

#113

Post by dragonwriter »

excalibur wrote: post #110

https://en.wikipedia.org/wiki/Identical_ancestors_point > In 2004, Rohde, Olson and Chang showed through simulations that the Identical Ancestors Point for all humans is surprisingly recent, on the order of 5,000-15,000 years ago. How can different populations of modern humans have interbred with different hominin species around 50k years ago when ALL of today's humans had the EXACT SAME SET OF ANCESTORS as recently…

> How can different populations of modern humans have interbred with different hominin species around 50k years ago when ALL of today's humans had the EXACT SAME SET OF ANCESTORS as recently as 15k years ago?

Differences in past populations, including the interbreeding at issue, can be inferred from modern genes for reasons actually laid out in your own link, in the paragraph after the one you quoted:

All living people share exactly the same set of ancestors from this point back, all the way to the very first single-celled organism. However, people will vary widely in how much ancestry and genes they inherit from each ancestor, which will cause them to have very different genotypes and phenotypes.

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

#114

Post by bregma »

c3534l wrote: 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 for half a million years in the harsh conditions of glacial and inter-glacial Europe and Asia. They had a rich culture of decorative arts and ceremonial burials. They were as capable of vocal speech as we are (same pharyngeal constructs, highly developed Broca's and Wernicke's regions in the brain). They encountered waves of dark-skinned Homo sapiens coming out of Africa and about 10,000 years later vanished from the scene. That there are light-skinned fair-haired Europeans today is evidence that they didn't vanish completely.

The only evidence that H. neanderthalensis and H. sapiens are separate species is the word of 19th-century French aristocrats who were concerned about maintaining racial purity.

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

#115

Post by mabbo »

excalibur wrote: post #110

https://en.wikipedia.org/wiki/Identical_ancestors_point > In 2004, Rohde, Olson and Chang showed through simulations that the Identical Ancestors Point for all humans is surprisingly recent, on the order of 5,000-15,000 years ago. How can different populations of modern humans have interbred with different hominin species around 50k years ago when ALL of today's humans had the EXACT SAME SET OF ANCESTORS as recently…

15k years isn't so short a period. Suppose a generation every 20 years or so. 50 per millennium. 750 generations in 15k years. If one person per generation settles 120 km further east than he/she was born (and odds are there would be more than just one) then 750 generations would be long enough to circle the planet twice.

Genes travel slowly, but in many directions at once. And there may be some advantage to the offspring of two people genetically "far" from each other, reinforcing via evolution whatever instinct lead to them travel.

15k years is more than enough time for all of us to share an ancestry.

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

#116

Post by renlo »

Juliate wrote: post #105
orange8 wrote: post #97

Earlier quoted context omitted.

I believe all animals definitely have some sort of language, and that the complexity of a language depends on its utility in facilitating everyday interactions and activities. What are the most complex activities you've seen elephants get up to?

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 trouble communicating with them, because we have trouble identifying and communicating with the terrestrial intelligence that surrounds us and is abundant.

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

#117

Post by Symmetry »

orange8 wrote: post #58
hashberry wrote: post #55

"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.

Elephants and whales have big brains but they don't have as many neurons as you'd think from their brain volume. For most mammals neuron count scales as roughly the 3/4 power of brain volume. For primates and birds it scales linearly.

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

#118

Post by simonh »

1000units wrote: post #59
orange8 wrote: post #58

Earlier quoted context omitted.

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.

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?

I think it’s unlikely they would evolve more advanced intelligence than its possible for them to make practical use of in their behaviour.

Now, clearly humans have been able to adapt our intelligence to uses far beyond the behaviours it evolved to support. Our ancestors 50,000 years ago had more or less the same brains we do. Nevertheless their behaviours were highly complex. They broadly did what we do, crating art, manufacturing artefacts from multiple processed materials, ornamentation, social rituals such as burials. We just take those behaviours a lot further.

To argue that whales might have sophisticated intellectual capabilities, you’d need to show what behaviours they exhibit that require them. Otherwise that intelligence would serve no evolutionary purpose and might actually be a survival disadvantage. See the cognitive trade off hypothesis.

https://www.quora.com/What-is-the-Cognitive-Tradeoff-hypothe...

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

#119

Post by blaser-waffle »

brohee wrote: post #89
hashberry wrote: post #55

"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…

> my favorite is that we simply outbred them because of our sex appeal I think not, Homo Sapiens just starves better, Neanderthal superior athleticism came at a huge calorie cost, so when preys became rarer Neanderthal starved faster than Sapiens.

As does are relatively short height. Shorter folks make it through famines better. The recent resurgences of tall folks is a byproduct of our caloric abundance.

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

#120

Post by excalibur »

dragonwriter wrote: post #113
excalibur wrote: post #110

https://en.wikipedia.org/wiki/Identical_ancestors_point > In 2004, Rohde, Olson and Chang showed through simulations that the Identical Ancestors Point for all humans is surprisingly recent, on the order of 5,000-15,000 years ago. How can different populations of modern humans have interbred with different hominin species around 50k years ago when ALL of today's humans had the EXACT SAME SET OF ANCESTORS as recently…

> How can different populations of modern humans have interbred with different hominin species around 50k years ago when ALL of today's humans had the EXACT SAME SET OF ANCESTORS as recently as 15k years ago? Differences in past populations, including the interbreeding at issue, can be inferred from modern genes for reasons actually laid out in your own link, in the paragraph after the one you quoted: All living peop…

This actually makes sense, thank you for actually reading the Wikipedia page rather than just searching for a quote :)

It doesn't really contradict this article, but there were a number of articles a couple of years ago about how Europeans had Neanderthal DNA that other ethnicities didn't share. In reality all modern humans are descended from the exact same Neanderthals, but Europeans still retain more of their genes.

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