Study of 1m-Year-Old Skull Points to Earlier Origins of Modern Humans

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 evidence says we're related to blacks. We believe it because the evidence says we're pretty much hairless apes. (And a lot of us aren't even hairless!)

There, feel better about it now?

This is completely and unequivocally rejected by the genetic evidence. The evidence is so absolutely overwhelming that even fucking Wolpoff came around and now says:

    It is broadly agreed that all recent/living human populations ultimately descend from Africans.

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Just to make sure I haven't missed some momentous event since the last time I was doing fieldwork, I even checked some unpublished books, review papers, and actual research.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.

But more importantly for this conversation, our brains use up a staggering 20-25% of our resting metabolic needs. A whale brain uses something like 3%.

For us to be able to devote 20% of our calories to our brains, we simply needed to have a huge excess in the number of calories we had available. This is why the cooking hypothesis makes sense. Once we were smart enough to get lots of excess calories, that opened the door to this new fitness landscape of organisms that could devote a ridiculous proportion of their food to their brains. It wasn't that we gave up something else, it's that this wasn't even a possibility before.

Well, that's false. But we killed off/interbred with all of the peer/near-peer species.

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.

The chimps that did get them we now call humans.

There were no chimps back then. We had a shared common ancestor, and subgroups gradually emerged and gradually became different enough that they stopped interbreeding (or were physically separated).

So it's not just brainpower, it's likely a combination of potential brainpower - which many species have/had - and fine motor control, which set up feedback loop that translated a mind/body synergy into practical evolutionary benefits.

Less extinction, and more evolution.

Your idea would be what's called a spandrel hypothesis, basically that language (or culture etc) is a side effect of other adaptive traits.

I've read, from a few separate sources that were not research papers, something similar that claimed the development was a result of existing in semi-aquatic environments such as home on land but swimming for food/safety. I neither agree or disagree (not my field, I don't possess appropriate background/information), but I do think of it when evolution of vocal cords is mentioned.

I don't recall the sources ATM, possibly something out of CoEvolution Quarterly or Bucky Fuller. Again, not research papers.

That means, if a trait is unaffected by the environment, then there's no attribution of why it developed; this is the default state.

I feel often in biology, there's a mindset of figuring out why features developed and that's great for pushing the field but it runs into a limit. Not every trait developed from a environmental pressure.

Some great apes can learn to use symbols for communication. Bees can use specific dances to indicate direction and distance.

Starting from what should be considered "writing" to how to identify specific artifacts as abstract words.

Some researchers spend years in the forest studying one animal to isolate one single word they're speaking. Understanding other kind of intelligences is a crazy complex task.

As does house finches: https://royalsocietypublishing.org/doi/full/10.1098/rspb.202...

Sperm whale codas exhibit contextual and combinatorial structure: https://www.nature.com/articles/s41467-024-47221-8

Ants have developed symbolic language: https://pmc.ncbi.nlm.nih.gov/articles/PMC10093743/

Everywhere we look close enough, we find life doing smart things.

https://en.wikipedia.org/wiki/Waggle_dance?wprov=sfla1

No I mean absolutely zero contact with or help from modern (say since the last 10,000 years) human civilization.

I mean literally giving birth in a forest and then raising the baby there without ever speaking a word around it or showing it any tools etc.

(this assumes that it will survive to 1-2 years old without any fatal sickness etc. but let's say that the mother/parents will get just enough "outside" help to make sure it does, but the baby itself is not to come in contact with any tech or language)

No no no, I don't mean going from already intelligent/sentient/sapient to MORE intelligent….

I mean, going from the levels of intelligence/awareness we see in insects → fish → chickens and cattle → monkeys/apes → what we consider "actual" intelligence as seen in humans.

Evolution of anything is obviously not some simple boolean switch: It's not like one day you're a full fish and the next day you give birth to an amphibian with legs.

But how would the gradual evolution of intelligence look and feel like?

Going from what we consider animals to be, to having awareness and introspective thoughts and future planning?

Is it like, do you have just 1 thought per day at first,

or can only count up to 3 for a few thousand years,

only plan for up to 1 day ahead, and remember that plan for only a few hours…

And when do all the clearly self-destructive things kick in, that we Modern Humans™ do that obviously harm individuals and the species? :)

You probably had Nicaraguan Sign Language [1] in mind. I think it’s a good example of the human brain’s ability to invent something and acquire knowledge easily. What I tried to show with my comment is that when human intelligence is discussed, it’s easy to refer to all instances of human achievements around us, but they are essentially accumulated cultural knowledge. Because of this, we tend to overestimate our intelligence, at least when comparing an individual human with an individual primate of another kind.

So, it’s also interesting why humans are probably unique in this ability to pass on and accumulate information, while other apes (and crows) limit this to skills like retrieving ants with sticks and breaking shells with stones.

[1] https://en.wikipedia.org/wiki/Nicaraguan_Sign_Language

What is being criticized here is an attitude that believes one is the only one capable of critical thinking and that everyone else is just an idiot who is already overwhelmed by the task of tying their shoelaces in the morning. This is simply arrogance and has little to do with constructiveness, let alone scientific ethos. You treat yourself to that little dopamine rush of saying “ackchyually” and then just carry on playing Bubble Shooter on your phone.

This is very common here on HN. And when this ultimately hardens into blanket skepticism toward institutions, you are closer to the flat-earthers than to the scientists.

Sure, modern homo sapiens outside of Africa are all descendants of a founding group that left Africa, but they are also descendants of hominids who returned to Africa from elsewhere as well as local hominid populations that had left Africa far earlier (like Neanderthals and Denisovans).