Barriers to crossbreeding with Neanderthals and Denisovans -discussion

Both of your posts can be the case. Girls desire men like Edward Cullen since they project traits that are "high quality" in males (tall and fit without being grotesque, clean and good smelling, a good provider, etc.).

Personally, he gives me a gay vibe. I like the werewolf one. :) I think for most women it's an age thing. Teenage girls like non-threatening, girlish men. Tastes change as you age. In my own case, however, even as a young girl, I always liked very masculine looking men. I spent my teens watching old movies to learn English.

My teenage crush:
Gable-as-Rhett-Butler-in-Gone-with-the-Wind.jpg



Strong jaw, strong cheekbones, strong chin and nose, big head, big body...I think I fell in love with my husband at first sight because he looks a lot like this.

However, the point is not about what attracts women; it's whether they are, on average, as naturally promiscuous as men, as apt to divorce sex from feeling. The answer, from science as well as personal experience is emphatically no.
 
Why not a Neanderthal male raping a human female? Although I suppose giving birth to a half Neanderthal child might have killed her.

This is the most plausible scenario to explain why human mitochondrial DNA shows no indication of Neanderthal–human admixture because of a sex bias towards Neanderthal male and human female pairings. Admixed offspring remained with their human mothers and thus introgressed Neanderthal alleles survived only on the X chromosome.
 
It is possible that the contact wasn't consensual in general. Of the three species, humans appear to have been the least well-equipped physically and strength-wise. And that would skewer DNA transfer towards Neanderthal and Denisovan males introgressing into human lines. However, given the length of our overlap with them, I find it hard to imagine that all the contact was violent. Humans vary too much behaviorally, and we know there was variation in Neanderthal breeding habits too.

However, in my experience the human girls are at least as bad as the human boys. They are just socially expected to be less obvious about it, and often far more heavily socially sanctioned. All that supernatural romance about hairy werewolves, twisted demons, dangerous vampires etc, etc. thats being churned out by the ton -its not the boys buying it.

The average Neanderthal male would have presented a formidable physical challenge. Even a Neanderthal female would have been hard to handle. Their disadvantage was not physical, but numerical. Adapted to colder ice-age conditions, they specialized in hunting/trapping larger game. But the climate warmed and modern humans, who were more omniverous and thus able to support larger populations within a given area, simply outnumbered them. If Neanderthals also had speech, communication, and/or language deficits compared to modern humans, that would have made it more difficult for them to coordinate resistance to human incursions.

DNA transferal between Neanderthals and humans was one-way: from Neanderthal males to human females, likely due to force (capture, kidnapping, rape, etc.):

Humans and Neanderthals share a small percentage of nuclear DNA. However, humans and Neanderthals do not possess the same mito­chondrial DNA. In mammals, mitochondrial DNA is exclusively maternally inherited. Taking into account an understanding of interspecific hybridity, the available data leads to the hypothesis that only male Neanderthals were able to mate with female humans. If Haldan's Law applied to the progeny of Neanderthals and humans, then female hybrids would survive, but male hybrids would be absent, rare, or sterile. Interbreeding between male Neanderthals and female humans, as the only possible scenario, accounts for the presence of Neanderthal nuclear DNA, the scarcity of Neanderthal Y-linked genes, and the lack of mitochondrial DNA in modern human populations.

https://www.researchgate.net/publication/269786511_Neanderthal-human_hybrids

A thing that puzzles me though, is that the out-of-Africa group seem to have encountered Neanderthals early on in the expansion process, interbred, and then kept expanding. At this point in time, the human wavefront appears to have had a pretty high Neanderthal component, before purifying selection cut it down. But this already admixed population would no longer breed with Neanderthals? How would that work?

Is it possible that the hybrids had such low fitness that only a few managed to reproduce and that only during an unusually beneficial period ? (Few competitors etc)

Or perhaps because Neanderthal populations had been decimated by, and were fleeing from, the onslaught of more numerous modern humans. There would have been less interbreeding events simply because there were many fewer Neanderthals.
 
I meant the blade tools that emerged ca 50 ka and spread over almost all Eurasia in a very short time replacing most of the blade tools made by Levallois technique.

That is exactly the kind of blade tool that I and the paper I link to am talking about. That's an inferior technique and "replacing" something doesn't make it better.
 
Neanderthals had plenty of time to expand, if their population remained low, it was because they were not inventive enough in exploiting resources nature offered.


That isn't true at all. Reproduction rates aren't connected to inventiveness; they're often negatively correlated. Less inventive, less competent populations breed more than more intelligent populations, as you in Europe are finding out.



The actual number of modern humans coming 'out of Africa' was very low as demonstrated by both Y- and mtDNA of which there are very few specific Eurasian clades (C, D and FGHIJK in Y-DNA). Expansion happened within Eurasia.

That's a load of BS, you can't use the limited understanding that fossil DNA evidence provides to show anything. Everyone agrees the expanding homo sapiens population was several times larger than the Neanderthal population.
 
911, population mixing does not lead to fixed amounts of genes holding the same proportions for generations after mixing anyway.

For a well-known example close to the modern age I give you -Djengis Khan! When born, he was one of 200 million male humans alive.Today, 0.5 % of human males descend from him and carry Y-chromosomes directly descended from him

There is no evidence for any of this, nor is it even possible. You are referring to wild speculatuons from the early 2000s which attributed the C3 star cluster to Genghis Khan. No direct evidence has ever linked Genghis Khan to C3 and all Mongol Borjigin elites sampled so far actually belonged to R1 haplogroups:

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0161622


Genghis Khan had a small number of children and 0.5% of Asia's population does not descend from him. Your problem with your "example" is that it's highly speculatory unproven BS.



During most of human history, the population was in equilibrium or close to it. Population growth, when it occurred was generally slow. That means almost as many kids dies as the number who lived to reproduce. So for example: if we have a F1 Neanderthal-Human hybrid who is 50 % of each species, he might have two kids who live to breed, and so the next generation will contain two 25 % Neanderthal individuals. But if the Neanderthal genes give a competitive advantage, he might have 3 kids who survive to reproduce. That means that the number of Neanderthal genes in the second generation is larger than the number in the first generation.

Over thousands of years, even very small statistical advantages in reproductive fitness can cumulate to very large sweeps of genes, as genes which give an advantage sweeps in to replace those who didn't. This is a process known as... evolution.

And yet again you're refusing to take in to account the fact that the Neanderthal popation was dwarfed at all times by the global modern human population. No matter how many kids a Neanderthal has; they can't make up for the immense population growth that Africa's climate enabled; in the meantime the number of unadmixed Neanderthals had dwindled by 40,000 YBP.
 
At least one of the papers proposed that the male hybrids were sterile.


Or they could have been victims of infanticide.

As someone pointed out, the major "cleansing" of their dna was in the testes and the brain,and interestingly enough, in the brain a lot of it was in the areas controlling verbal processing.

Maybe not. We don't have a full enough sequence of Neaderthal genomes to determine which genes are missing and which aren't.

Levantine Neanderthals never yielded autosomal DNA.


In the meantime:

https://www.smithsonianmag.com/smar...rary-humans-skull-shape-brain-size-180971043/


There's absolutely no doubt in my mind that they were more primitive.

Prove it, then. You can't prove it based on wild speculations about limited genetic observations. The fossil record shows that modedn humans were astonishingly primitive compared to Neanderthals.
 
https://www.sciencedirect.com/science/article/pii/S0047248408001395



It is widely believed that the change from discoidal flake production to prismatic blade-making during the Middle?Upper Paleolithic transition in Europe led to enhanced technological efficiency. Specifically, blade-making is thought to promote higher rates of blank production, more efficient and complete reduction of the parent core, and a large increase in the total length of cutting edge per weight of stone. Controlled replication experiments using large samples, computer-assisted measurements, and statistical tests of several different measures failed to support any of these propositions. When resharpened, the use-life of flake edges actually surpasses that of blades of equivalent mass because the narrower blades are more rapidly exhausted by retouch.



Basically blade technology emerged as the easier, less efficient, less thought-out and less aesthetic substitute to Levallois flake technology, likely by early modern humans who lacked a sufficient amount of key Neanderthal intelligence genes necessary to produce Levallois flakes. Recent genetic analysis has confirmed that Neanderthal alleles are rich in areas of the human genome that code for brain architecture and intelligence. They were far more gifted than moderns, particularly in regards to visual-spatial mastery and abstract thought (as evidenced by the dry distillation of birch tar 80,000 years ago, the superior Levallois flake method, etc).




Just bumping this post to the next page to give bicicleur the opportunity to appropriately respond to it instead of running away from it like he did on the previous page. Upper Paleolithic blade production was an inferior substitute for the Levallois flakes which had dominated the world for hundreds of thousands of years, its spread indicates increasing mediocrity.
 
Basically, as a recap:

1.) For +200,000 years Neanderthals dominated this planet

2.) Neanderthals were the #1 innovaters on planet Earth for +200,000 years

3.) Modern humans imitate and learn from (and receive a biodiversity injection from) Neanderthals ca. 95,000 years ago at Skhul and Qafzeh in Israel, switching over to Mousterian Levallois flake core methods.

4.) Neanderthals are practicing complex chemistry 80,000 years ago.

5.) All modern human-Neanderthal interbreeding events are between Neanderthal males and modern human females.



Based on these 5 simple points alone; it is a better bet to conceptualize the modern human-Neanderthal relationship as being similar to the relationship between Native Americans and conquistadors, than simple #MeToo rape allegations against Neanderthals.
 
Maybe not. We don't have a full enough sequence of Neaderthal genomes to determine which genes are missing and which aren't.

We know for sure that archaic alleles that affected those tissues were disproportionately subject to selection. The selection coefficients for your convenience:

SrXJVaM.png


What about the fossils makes you think Neanderthals were less primitive?
 
LOL clearly Neanderthals were so advanced that they developed industrial civilization and Internet porn, stopped having kids, and started shipping in modern humans as cheap labour. But they were just too nice to colonize tropical countries. That must be it. Those superior sexy Neanderthals.

Dude your therapist must be writing some interesting monographs.
 
We know for sure that archaic alleles that affected those tissues were disproportionately subject to selection. The selection coefficients for your convenience:

No we do not, you psychotic freak. What you showed me is a table listing supposed selection values based on limited archaic genomes from a few fossils; none of them the Levantine Neanderthals that much of the interbreeding is supposed to have occured with.


What about the fossils makes you think Neanderthals were less primitive?

Already listed many things here such as the inflated maxillary sinus, large nose, small mastoid process, midfacial projection/zygomatic retreat, etc. Not to mention lamboidal flattening and the "en bombe" coronal profile of the braincase.
 
LOL clearly Neanderthals were so advanced that they developed industrial civilization and Internet porn, stopped having kids, and started shipping in modern humans as cheap labour. But they were just too nice to colonize tropical countries. That must be it. Those superior sexy Neanderthals.

Only people with Neanderthal DNA ever did any of that, Einstein.
 
Yes, clearly it's the Neanderthal DNA present everywhere but on 2/3 of one continent that makes the difference. That's why Native Americans and Aboriginal Australians came so close to winning the Scramble for Africa, LOL.
 
No we do not, you psychotic freak. What you showed me is a table listing supposed selection values based on limited archaic genomes from a few fossils; none of them the Levantine Neanderthals that much of the interbreeding is supposed to have occured with.

Explain the differential selection coefficients, then.




Already listed many things here such as the inflated maxillary sinus, large nose, small mastoid process, midfacial projection/zygomatic retreat, etc. Not to mention lamboidal flattening and the "en bombe" coronal profile of the braincase.

Look at Levallois producing Jebel Irhoud and compare it to any Neanderthal skull. It should be immediately obvious which one we're related to.

Do you mean to say that Neanderthals were less primitive than modern humans as well? :embarassed:
 
Yes, clearly it's the Neanderthal DNA present everywhere but on 2/3 of one continent that makes the difference. That's why Native Americans and Aboriginal Australians came so close to winning the Scramble for Africa, LOL.

NatAms and Aboriginal Australians were separated from the course of Eurasian human societies (which developed the fastest) for thousands of years yet NatAms did build large civilizations that non-Caucasiform Africans did not. The upper part of Africa that did advance was Neanderthal admixed. Abkriginal Australians are the sole exception -- they also have a lot of non-Altaic Denisovan admixture.

Basically you're clearly being a disruptive charlatan who is afraid of admitting that only people with Neanderthal ancestry have ever built a civilization or enjoyed a high quality of life.
 
Sure, just because the correlation is super-weak and you have no actual evidence of causation is no reason not to immediately accept your hypothesis, LOL.
 
Explain the differential selection coefficients, then.

Again it's based on limited data.

Look at Levallois producing Jebel Irhoud and compare it to any Neanderthal skull. It should be immediately obvious which one we're related to.

Unfortunately for you, Jebel Irhoud was mixed with Neanderthals (especially in his brain):

https://pdfs.semanticscholar.org/9368/a26741c151e82714a0523b13477ca5aef716.pdf

Nonetheless, the available descriptive and metric approaches suggest that, because of the parietal shape, the Jebel Irhoud 1 neurocranium and endocast are comparable with the Neandertal morphology.

Furthermore, most people would look at the face of Jebel Irhoud (left), and the face of the classical Neanderthal La Ferrassie 1 (right), and conclude that La Ferrassie was their ancestor:

DjqSYhmXcAE6wFO.jpg


Do you mean to say that Neanderthals were less primitive than modern humans as well? :embarassed:
The picture above says it all.
http://www.bbc.com/earth/story/20170214-your-face-is-probably-more-primitive-than-a-neanderthals
Neanderthals had a less primitive facial morphology than modern humans and were more evolved.
 
Again it's based on limited data.

That doesn't explain the trend. The data is equally limited across all tissues.



Unfortunately for you, Jebel Irhoud was mixed with Neanderthals (especially in his brain):

https://pdfs.semanticscholar.org/9368/a26741c151e82714a0523b13477ca5aef716.pdf



Furthermore, most people would look at the face of Jebel Irhoud (left), and the face of the classical Neanderthal La Ferrassie 1 (right), and conclude that La Ferrassie was their ancestor:

DjqSYhmXcAE6wFO.jpg



The picture above says it all.
http://www.bbc.com/earth/story/20170214-your-face-is-probably-more-primitive-than-a-neanderthals
Neanderthals had a less primitive facial morphology than modern humans and were more evolved.

Irhoud clusters with modern humans, although he retains some archaic feautes:

https://www.nature.com/articles/nature22336?xid=PS_smithsonian

~ 13k B.P. Iwo Eleru from Nigeria clusters closer to Neanderthals as well, because he retains archaic features. It's unlikely that Neanderthal ancestry got to Morocco or Nigeria.

I guess you're free to obsess whatever primitive features modern humans retained. When talking about h. sapiens we're primarily interested in behavioural modernity. Hence this is very similar to us:

Figure_11__1_.1496853535.jpg


While this one is sits on another phylum:


8afe3bed0e176d2fb8ebeaba752bb9a5.jpg


I don't mean to be insensitive, but the latter would probably look quite scary and even ugly to modern humans.
 
That doesn't explain the trend. The data is equally limited across all tissues.

Neanderthal ancestry is also apparently limited and so is the Neanderthal genome reconstructed thus far.

Irhoud clusters with modern humans

On facial morphology. Brain-wise, he's a Neanderthal.

, although he retains some archaic feautes:

These "archaic" features are not seen in archaic homo sapiens but are derived cranial features found in Neanderthals.

Hence:

Nonetheless, the available descrip- tive and metric approaches suggest that, because of the pari- etal shape, the Jebel Irhoud 1 neurocranium and endocast are comparable with the Neandertal morphology.

~ 13k B.P. Iwo Eleru from Nigeria clusters closer to Neanderthals as well, because he retains archaic features. It's unlikely that Neanderthal ancestry got to Morocco or Nigeria.

Actually, it's highly likely Neanderthal ancestry got to Morocco, which is close to Spain (Neanderthal turf). Neanderthal ancestry is likely to have made it to Nigeria by 13k YBP.

I guess you're free to obsess whatever primitive features modern humans retained. When talking about h. sapiens we're primarily interested in behavioural modernity. Hence this is very similar to us:

Neanderthals were behaviorally modern. Dry distilling birch tar is a modern behavior.


 

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