61–70 of 186 posts
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Didn't a lot of other great apes evolve intelligence similar to ours, but we more or less drove them all to extinction?
it's interesting to think that since humans got established, becoming too intelligent became a disadvantage? Like there's a glass ceiling.
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"Why humans evolved intelligence but orangutans did not". There's a different way to think about this that is closer to how evolution actually works and will make the answer clear. Our common ancestor (common to orangutans and humans) did evolve intelligence (concurrently with harnessing fire, clothing etc.). Not all of them, but some of them. And they broke off from the group. We now call them humans.
Intelligence must surely be a cluster of evolved changes, let's say A-Z. Each of those letters must have appeared, and been advantageous on their own (or they wouldn't have persisted). So why didn't chimps get some of them? For example, chimps have hands, but do not exhibit anywhere near the dexterity and agility of human hands.
Now if these costs are indeed less than the fitness advantage of a chimp having more dexterous hands, and that is in biological fitness as in reproductive success not the colloquial 'fitness' as in going to the gym, and that mutation for dexterous hands is present among the breeding population, you will expect to see offspring with that mutation, having higher fitness, to increase in frequency in the population.
There are a lot of potential edge cases to consider as well. Maybe the dexterous hands allele is very close to a very bad allele in chimps, such that through recombination it is likely that these two alleles are inherited together (called linkage). You'd see both these alleles purged from the population over time through purifying selection.
There is the population history aspect to consider. Maybe you don't need dexterous hands if your population is still living in the jungle among plentiful calories like the chimpanzee. Maybe it is more relevant to comparatively more feeble humans that were pushed out of that jungle by physically stronger ape populations into more nutrient poor environments, where suddenly the increased fitness from the advantages dexterous hands might bring now pay for their energy costs.
Out of africa is basically false, there were decently advanced walking hominids in asia a long time ago. Then they migrated west, africa was the origination, but that origination was not the ~50k years ago like was frequently claimed
All the evidence we have points to the vast, vast majority (>90%) of non-african human ancestry originating from hominin populations that were in Africa around 60-80k years ago, and were anatomically modern about 300k years ago. This article is about an ancestral clade of archaic hominins that contributed around 2% of modern non-african ancestry globally, that we've known about for years. OOA (with minor admixture) i…
It isn't really. Serious historians and geneticists take great issue with it.
It's only really the pop-anthropologists (the non-rigorous social science ones) who think OOA is a settled issue.
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It is also the consensus position for a lot of bad reasons though. There is an assumption that belief in, or even reasonable agnosticism towards, any other theory can only be motivated by racism. There are many people that believe OOA because they want to believe it, because they want to believe we are all more similar than we are different, etc. Multiregional hypotheses are perfectly plausible. We have very limited…
There are many people that believe OOA because they want to believe it But, also, There are many people that [do not] believe OOA because they [do not] want to believe it . That's why we look at genetic evidence, to eliminate nonsense. That evidence strongly points to chimps, gorillas, humans etc all coming from the same place. If it makes you feels better, think of it this way: we don't believe OOA because the evide…
No. Non-African humans have genetic lineages that do not occur anywhere in Africa.
This doesn't mean OOA is necessarily false, but does makes it much less likely.
Also, lumping in primates is a red herring. The resolution of our gene clade knowledge doesn't go that far back. Dreaming about some hypothetical ape ancestor is a vibe, not a science.
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Considering human intelligence is very social, I wonder if bias to focus on individual humans leads us to a wrong way of understanding why it arose… One of my pet theories is that it may be related to vocal cord development[0], where losing certain physiology that allows apes to be louder allowed humans to be more specific , if quieter, with enhanced pitch control and stability offering higher information density com…
Depending on which factors you weigh most heavily, sociality theories usually fit into either individual or group selection categories. They're sort of the default consensus, but not one that's firm. Your idea would be what's called a spandrel hypothesis, basically that language (or culture etc) is a side effect of other adaptive traits.
As to “side effect”, given better communication and consequently cooperation and potential for more complex collectives lead to persistent survival of the species in the environment, they seem like a pretty straightforward evolutionary advantage that would be expected to be naturally selected for in the first place. If anything, chances are in long term the great larynx update is the real side effect, it just happened to be a trait enabling all the above evolutionary advantages.
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All the evidence we have points to the vast, vast majority (>90%) of non-african human ancestry originating from hominin populations that were in Africa around 60-80k years ago, and were anatomically modern about 300k years ago. This article is about an ancestral clade of archaic hominins that contributed around 2% of modern non-african ancestry globally, that we've known about for years. OOA (with minor admixture) i…
> OOA (with minor admixture) is the consensus position for a lot of excellent reasons It isn't really. Serious historians and geneticists take great issue with it. It's only really the pop-anthropologists (the non-rigorous social science ones) who think OOA is a settled issue.
But if you're genuinely trying to say that the broad strokes out of africa model isn't consensus, I have no idea what you're talking about. Just to make sure I haven't missed some momentous event since the last time I was doing fieldwork, I even checked some unpublished books, review papers, and actual research. They all talk about OOA as completely settled or instead simply assume it.
Is this like a CAS thing? Truly baffled.
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All the evidence we have points to the vast, vast majority (>90%) of non-african human ancestry originating from hominin populations that were in Africa around 60-80k years ago, and were anatomically modern about 300k years ago. This article is about an ancestral clade of archaic hominins that contributed around 2% of modern non-african ancestry globally, that we've known about for years. OOA (with minor admixture) i…
> OOA (with minor admixture) is the consensus position for a lot of excellent reasons It isn't really. Serious historians and geneticists take great issue with it. It's only really the pop-anthropologists (the non-rigorous social science ones) who think OOA is a settled issue.
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chimpanzees, gorillas, orangutans evolved intelligence too. They are smarter than most other critters in the jungle. Just all not as much as the lineage that leads to humans. It's actually quite difficult to define human intelligence. Every time we think we find something unique by humans eventually some animal turns up that can do it too. It may be all just a question of degree and how it's used.
From what I've heard, language is unambiguously unique to humans, if you consider grammar an integral part of languages. You can teach chimpanzees hand signs, but they could never make the leap to stringing them together under a coherent rule: something like the difference between "Mom give me cookies" vs "I give mom cookies." (I'm no expert, so take that with a grain of salt.)
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We don't know. All of the great apes are incredibly intelligent in comparison to most other animals. The basic roots of our intelligence are probably a common feature to the whole family, but there's no consensus on why it's so advanced in humans. Any paleoanthropologist can rattle off about half a dozen possible explanations, but we honestly don't have enough evidence to really distinguish if, when, and how these we…
Didn't a lot of other great apes evolve intelligence similar to ours, but we more or less drove them all to extinction?
Less extinction, and more evolution.