Back of the napkin estimation: a million years is 40,000 Homo generations, you might get a valuable mental mutation maybe every 500 generations, that's only 80 mental mutations between us and the Homo species that made this axe. So these guys were just about as smart as us.
On the other hand, modern human's super-intelligence might have come from a lucky admixture of Neanderthral and Denisovan genes rather than slow mutation. There's evidence from cultural artifacts that even 100,000 years ago humans were less intelligent then us.
Perhaps not less intelligent, but just possessed of a mental framework that was less capable.
From a paper describing "the Romulus and Remus hypothesis"[1],
"the leap from rich-vocabulary non-recursive communication system to recursive language 70,000 years ago was associated with acquisition of a novel component of imagination, called Prefrontal Synthesis, enabled by a mutation that slowed down the prefrontal cortex maturation simultaneously in two or more children"
That’s incredible, and very compelling. It would explain the relatively sudden development of behavioural modernity over the few decades from 70k years ago.
I’ve read competing theories about the sudden development of abstract thinking and it’s propagation through speech as a form of memetic contagion, but I never really found it convincing. This makes perfect sense.
The idea that recursion was the key mutation that led to language is not doing so well lately. It turns out that non-human animals already can produce sequences with recursive structure [1]. It's also not clear that all languages have nested recursive structures.
The hypothesis here is quite a bit more nuanced and specific than that. As a laymam, I found it worthwhile to read the whole article. In the course of making its case it touches on many fascinating topics. I found the case quite compelling, though I can't rule out that someone more familiar with the facts can poke holes in it.
One of the most fascinating books I’ve ever read, really. It’s unlikely to be true, and unverifiable even so, but is a coherent and compelling frame through which to observe the world.
Ancient humans did not have a continuous supply of food, refrigerators, enriched foods, supplements. They would regularly have to choose between eating decomposed food or starve.
Iodine consumption alone is responsible for a moderate IQ boost (15 points). And if you start making nutrition worse, you will see more cognitive impact.
During pregnancy, they could not go to the doctor and get their blood tested and given dietary supplements. And newborns did not have access to baby formula when the mother's milk supply was insufficient. These factors can also result in lower IQ.
Humans mixed with neanderthals because they had an immunological advantange. Anatomically modern humans inhabited Africa, Neanderthals inhabited other regions. Neanderthal territories had different pathogens that Neanderthals were better prepared to deal with, so the humans that mixed with neanderthals were healthier that the ones that did not. Eventually most neanderthal genes not related to immunity were knocked out from the gene pool by natural selection.
Not all evolution depends on mutation. Genes can exist in a gene pool, but be rare. Selection can change that pretty quickly. Multiple genes can interact to affect traits. etc.
You can go from average dog, to a distinct breed of dog (behaviourally or physically) within very few generations. This doesn't require new genes, or many of them. Natural selection can also work pretty fast this way.
YNH's theory is that evolution of "superintelligence" is memetic, rather than genetic. Starting at about 100kya, cultural evolution was taking over as the main factor driving behavioural changes.
> There's evidence from cultural artifacts that even 100,000 years ago humans were less intelligent then us.
The same could be said about 10kya or 1kya. Medieval artifacts are far less sophisticated than ours. The brains are similar.
Isn't what you said impossible by construction? You're saying ~80 "valuable" mental mutations wouldn't make us smarter, but if 80 of them wouldn't make us smarter, were they really valuable of mutations?
Bottom line is it's very difficult to know. A few small changes could make a huge difference, particularly if said changes affect the architecture of the prefrontal cortex.
Another possibility would be that these humans were about as mentally capable as we are in terms of reasoning and planning, but didn't have language abilities like we do. All of our technology builds on prior technology, which we learn about using language. If your parents can't effectively teach you about their tool use...
>There's evidence from cultural artifacts that even 100,000 years ago humans were less intelligent then us.
Do you have more info on this idea? What approach did researchers use to try to measure intelligence based on cultural artifacts used in a context we can't see for purposes we can only guess at?
> that's only 80 mental mutations between us and the Homo species that made this axe. So these guys were just about as smart as us.
I don't understand that. How could relative intelligence be inferred from just the number of mutation that occurred? I'm no biologist, but from what I understand a single genetic mutation might have a huge effect or a very minor effect.
> might have come from a lucky admixture of Neanderthral and Denisovan genes
You probably didn't mean to step in a minefield here, but not all human populations have Neanderthal genes. The prevailing thesis is that mostly complete (minus fiddling like lactose tolerance and pigmentation) modern humans were involved in the out-of-Africa migration ~60k-100k years ago.
The percentage of Neanderthal DNA in modern humans is zero or close to zero in people from African populations, and is about 1 to 2 percent in people of European or Asian background.
Personally I have nearly 4 percent according to 23andme - not sure what benefits this may or may not have given me. I'll be interested to see if my children inherit this.
Of those mutations, what became of the ones that lost out? Why versions of humanity were left by the wayside, along the path of evolution?
Are we ancestors of a common and small band of winning apes, who won our over those of a quite different mindset? Some tribe of fifty or so individuals that eradicated all of the competition?
In another timeline we might have evolved into speechless and peaceful gentle folk instead of the tribes of ruthless competitors that make up today’s world. And markedly less populous too, maybe, and probably without making footprints on the moon or conceiving plutonium warheads. Maybe just as likely to have done so, maybe even sooner than our current version of the species.
Yet another reason to pick up Niven’s Ringworld some time soon. In that case it was de-evolution, but the ideas feel similar.
I have a theory that we actually domesticated ourselves. Yes, the first animals humans domesticated were humans. We became less violent, more amenable to following leaders.
Environmentally we know if you took a modern human back then they will be at least 20 IQ points less. Probably far more from lack of micro-nutrients and the Flynn Effect.
On top of that our IQ will have changed over hundreds of years. We have evolved living in cities, it genetically changed our minds, see the Peppered moth for the cliche on cities and evolution.
It's probably only in the last 100 years our evolution has stopped, perhaps moving backwards but we are going full into intelligent design.
>that's only 80 mental mutations between us and the Homo species that made this axe.
To this
>These guys were just about as smart as us.
You don't know how much of an influence any individual mutation could have made. Also there's no reason to suspect more than [or less than] one mutation per generation.
Just look at the range of "gifted" people in our society - mutations which likely enable savants and such. Men like Newton and Da Vinci, if their successes are due to genetic mutations (I suspect to a significant degree this is the case) placed in another time could individually make the difference between a stone and metal age.
Point being, 80 generations of mutation may be enough to drastically change the human mind - especially considering the immense selection pressure for certain kinds of intelligence, which varies with culture and technology (e.g. stone vs metal age).
Edit: I suppose this comes down to how much evolution you believe happens in the form of punctuated equilibria
>On the other hand, modern human's super-intelligence might have come from a lucky admixture of Neanderthral and Denisovan genes rather than slow mutation
Be careful saying that if your HN account can be linked to your real identity. I've seen some people get #cancelled for that.
What was published about the Kalahari Bushmen by the Marshall family (Laurence Marshall, co-founder of Raytheon) provides some of the best real connections we have to early human life.
If you’re interested in this stuff, I really enjoyed Elizabeth Marshall Thomas’s “The Old Way” and recommend it.
I wonder if they were hunting hippos, or if they scavenged the bone from a carcass. Hunting hippos must either be an act of extreme confidence, or extreme desperation.
They often used things like cliffs to help hunt mammoths though, right? Seems a trickier thing to accomplish with hippos, although I suppose you could lure them away from the water. Planning and teamwork must have been key.
People are incredible hunters, those that specialize in hunting. Crafty, dangerous, innovative. We have plenty of modern examples of people hunting dangerous animals with very basic tools. An average lion pride can't kill an elephant. A specialized lion pride can. Humans are like this, but way more. Way, way more.
My default assumption is "these people knew how to hunt hippos." A neighboring band may not have.
> The craftsmanship of the tools at the Konso site, as well as other sites, "suggest that Homo erectus technology was more sophisticated and versatile than we had thought. And the bone handaxe occurrence fits in nicely," Suwa said.
H. erectus used advanced flaking techniques to create the hand axe. Tools, fire, advanced social organization, and migration through a large part of Eurasia; all without spoken language.
I don’t think the name H. erectus is meaningful to the general population. I wonder if we shouldn’t associate Turkana Boy as a stand-in much the way Lucy is well known in popular culture. This is a unique and important Homo species; “ancient human ancestor” is too nebulous for my liking.
According to Wikipedia [1] the science is not as settled as I thought but my understanding is that from the nerves needed for breath control to various vocal apparatus, erectus’ speech would have been primitive at best. Speech, however, is not the only way to express language.
An innovation in spoken language is one of the theories used to explain the Great Leap in modern sapiens.
I'm trying to come up with alternative ways to convey meaning as precise and detailed as to carve handaxes from bone without using spoken language, primitive or not.
Maybe some mix of sign language, sound and pantomime?
Hand axes would be easy to convey: demonstrate creation and use, repeatedly, and help learners do both. Homo Erectus made hand axes the same way for a million years, without much innovation, to the point that it's been hypothesised they were more like bird song or bird nests than cultural artefacts. See e.g. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5066817/
this is a complete joke. probably a bone fragment sheered off from the hippo fighting with a saber tooth tiger. these “discoveries” from so long ago are at best theories. maybe a since extinct giant beaver, carnivore rodent species was chewing into the femur to create a notch to secure it to another bone while framing out it’s bone, beaver den.
On the other hand, modern human's super-intelligence might have come from a lucky admixture of Neanderthral and Denisovan genes rather than slow mutation. There's evidence from cultural artifacts that even 100,000 years ago humans were less intelligent then us.