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The human brain grew as a result of the extinction of large animals: new paper

phys.org

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Re: The human brain grew as a result of the extinction of large animals: new paper

#71

Post by jjk166 »

statstutor wrote: post #60
TeMPOraL wrote: post #51

Earlier quoted context omitted.

> The unstated assumption is that humans are somehow better than chimpanzees "Better" always has to carry the "at what?" part, explicitly or implicitly. There's no universal Better, thus humans aren't Better than chimpanzees - but humans are better than chimpanzees at quite a lot of things, including intelligence, learning, preserving knowledge across generations, use of tools... > therefore that we must reverse engi…

I appreciate these points, which are well-considered. > But it's interesting why this is the case. Why us, and not chimpanzees. As you admit, we could ask about exceptional adaptations in other species, e.g. "why do birds rule the sky, and not other species?". This might be sometimes studied, but there is not nearly a comparable level of interest in that form of exceptionalism. I'd say there's so little interest, tha…

Evo-psych is certainly concerned with the psychology of other animals - why for example the peacock has its feathers. But we can't have a peacock say "I don't know, the feathers don't seem sexy to me, but if I were a tiger I think I'd be scared of them."

Humans have both much more complicated psychologies than most animals (whether we have true peers is debatable), and we certainly are much easier to collect data on. It makes sense that human evo-psych should dwarf animal evo-psych for the same reasons terrestrial-biology dwarfs astro-biology. I wouldn't interpret that to mean we don't consider the questions interesting.

Re: The human brain grew as a result of the extinction of large animals: new paper

#72

Post by jjk166 »

marshray wrote: post #70
tashoecraft wrote: post #57

Earlier quoted context omitted.

It's interesting as it's a common argument that "meat caused us to have big brains, meat good", but that analysis might not be so clear cut. If this paper is right it may be more of the search for meat is what caused our brains to grow and less so meat protein.

It seems nonsensical to me that simply eating meat protein could somehow cause a genetic change leading to great-grandchildren with larger brains.

It doesn't cause the genetic change, the genetic change is random. But if you were, simply by chance, born with a bigger brain that required more calories to support, you would be at a disadvantage to everyone else, and your mutation would quickly die out unless you were in a situation where you had excess calories available, such as by eating meat.

Re: The human brain grew as a result of the extinction of large animals: new paper

#75

Post by sitkack »

JumpCrisscross wrote: post #7
airhead969 wrote: post #2

You don't chase down most little critters, you bait and trap. That does require being less of a dummy.

> You don't chase down most little critters, you bait and trap The switch, from large to small, seems critical. Hunting big game requires cooperation and communication. That tooling gets supercharged when it has to domain switch. (Counterfactual: forcing lions to sustain themselves on rabbits will probably produce prides of dead lions.)

https://en.wikipedia.org/wiki/Protein_poisoning

Re: The human brain grew as a result of the extinction of large animals: new paper

#76

Post by jjk166 »

rickspencer3 wrote: post #19

The assertion that humans are unable to stop themselves from completely depleting the resources that they depend on rings true to me. I think Jared Diamond wrote a whole book about this.

Can you name a single culture that knowingly overexploited a resource they could not live without until they died out?

There have certainly been cases of overexploitation leading to the extinction of species that people didn't need to survive, as well as potential cases where human activity may have led to ecological collapse by mechanisms the people did not understand, but I honestly can't think of a single instance where a substantial population depleted a resource it knew it needed to survive.

On the other hand, I can think of many cultures that lasted for many thousands of years in geographies with limited resources like islands.

Re: The human brain grew as a result of the extinction of large animals: new paper

#77

Post by BerislavLopac »

I am convinced that a lot of human traits could be explained if, at a critical point in our evolutional history, our ancestors spend a lot of time wading in shallow water -- not unlike those Japanese macaques who keep warm at winter by dipping in hot springs. [0]

Bipedalism, body hair patterns subcutaneous fat, large brain (and, very much related to it, difficult birth), even language -- all these features make a lot of sense if you spend a lot of time in the water, leaving it occasionally to forage.

Unfortunately, I am aware of very little research in that direction, and many attempts have been shot down because of the bad reputation of the original "aquatic ape hypothesis" [1].

[0] https://www.nationalgeographic.com/animals/article/japanese-...

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

Re: The human brain grew as a result of the extinction of large animals: new paper

#78

Post by iujjkfjdkkdkf »

_RPL5_ wrote: post #54

I find their hypothesis suspect. > According to the researchers, the decrease in the size of game and the need to hunt small, swift animals forced humans to display cunning and boldness—an evolutionary process that demanded increased volume of the human brain. There are plenty of predators that hunt fast small prey, but don't have advanced cognitive capacities. Cats, for example, are adapted to hunting rodents, but h…

I think some cats are different because they are antisocial and there aren't that many of them. Compared to humans (and e.g. dogs) that have to hunt but also feed a group and support a social structure. Social cats like lions I believe do mostly eat bigger game. But cats overall are also extremely smart compared to most animals. Look into how intelligent tigers are. But they dont collaborate so they don't need that side of intelligence.

I do like your idea about the extant hunter gatherers, that should be easy to confirm.

Re: The human brain grew as a result of the extinction of large animals: new paper

#79

Post by jbotz »

JumpCrisscross wrote: post #7
airhead969 wrote: post #2

You don't chase down most little critters, you bait and trap. That does require being less of a dummy.

> You don't chase down most little critters, you bait and trap The switch, from large to small, seems critical. Hunting big game requires cooperation and communication. That tooling gets supercharged when it has to domain switch. (Counterfactual: forcing lions to sustain themselves on rabbits will probably produce prides of dead lions.)

I just watched "Kingdom of the White Wolf" on Disney+ which has exactly that situation. The white wolves of Ellesmere island hunt musk oxen; there isn't much else there except snow hares. At one point after not managing to take down a musk ox for a while they do hunt the snow hares and manage to get one... which serves to cement their pack bonds, but the calories gained were probably less than what the spent on that hunt.

Great mini-series, recommended.

Re: The human brain grew as a result of the extinction of large animals: new paper

#80

Post by robwwilliams »

A “just-so” story; not science. So many factors could have and probably did contribute to CNS enlargement. But no way for this article to be more than a plausible speculation. Most work on “human exceptionalism” falls into the just-so story category. Not actually pseudo-science, but para-science that cannot be tested or deconfounded.
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