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TIL The brains of modern humans are around 13% smaller than those of Homo sapiens who lived 100,000 years ago (piefed.social)
submitted 1 month ago by to c/til@lemmy.ca
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[–] 24 points 1 month ago (2 children)

god damn austerity, we can't have shit these days, even our brains have to meet efficiency quotas and "rationalization".

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    • [–] 7 points 1 month ago

    1-How do we eat ?

    2-Why do we eat?

    3-Where are we going for lunch ?

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    [–] 3 points 1 month ago (6 children)

    It's coincidental with the human adoption of farming. We changed the food source people have, and that impacted brain and body development. We absolutely see this modern day with malnutrition.

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  • [–] [S] 7 points 1 month ago (5 children)

    It’s coincidental with the human adoption of farming.

    So far it looks like no hypothesis holds water. For example this one about farming is talking about a timeframe of 10.000 years. The shrinkage started 100.000. So there is a 90.000 years gap, that is left unexplained

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  • [–] 2 points 1 month ago (4 children)

    via https://doi.org/10.3389/fevo.2021.742639

    brain size has remained steady in H. sapiens until a rapid and dramatic change point only 3,000 years ago

    and if we estimate farming was 10,000 years ago, we can't rule out one influenced the other.

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  • [–] [S] 4 points 1 month ago (3 children)

    Yes, DeSilva published the 2021 paper you linked. In 2022 he got criticism from Villmoare and Grabowski (see: Did the transition to complex societies in the Holocene drive a reduction in brain size? A reassessment of the DeSilva et al. (2021) hypothesis). Then in 2023 DeSilva revised his argument in (link above, in the description), extending the date back, still not giving anwers about the shrinkage observed since 100.000 years ago.

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  • [–] 2 points 1 month ago (2 children)

    Then in 2023 DeSilva revised his argument in (link above, in the description), extending the date back, still not giving anwers about the shrinkage observed since 100.000 years ago.

    yeah, from the last 3,000 to within the last 10,000 years, with the sharp decline ~5,000 years ago... which does line up with widespread adoption of agriculture still.

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  • [–] [S] 2 points 1 month ago (1 child)

    Of course you can choose to believe what you want.

    The point I was trying to make is that there is no scientific consensus on the topic about how global the decline was, when it began and why it happened - as well as if it is related to the formation of complex societies, farming, language, dietary changes, temperature, or body size.

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    • [–] 2 points 1 month ago

    I bet it has to do with the development of spoken language. That had to have freed up some brainpower that was previously tasked with processing body language, smell, context, etc.

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    [+] -49 points 1 month ago (22 children)

    Makes sense. Back then every day was survival and we had to think our way out of a lot of situations, just to live for one more day. Nowadays we wait for our government to feed and cloth us.

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  • [–] 20 points 1 month ago (3 children)

    Allow me to read the article for you:

    As smaller and better organised brains were able to perform more complex computations, metabolically expensive larger brains simply became unnecessary

    Tattersall believes that the catalyst that caused this change in thinking style was the spontaneous invention of language. This led to the neural pathways of the brain being reorganised in a more metabolically efficient way, allowing humans to get more "bang for their buck".

    In other words, as smaller and better organised brains were able to perform more complex computations, metabolically expensive larger brains simply became unnecessary.

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  • [–] 1 point 1 month ago (2 children)

    Tattersall believes

    This is just an educated guess. No one really knows why it happened. All we have is a handful of fossilized skulls to base this on.

    While I'll take their educated guess over my own musings, that doesn't mean they're absolutely correct. No one knows for certain.

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  • [–] 1 point 1 month ago

    Oh, so you've heard of this thing called "science" before?

    We can get some idea of what their brains looked like based upon imprints left on the inside of the skull. We can get an idea of relative intelligence based on artifacts, like tools and art. If you know that cranial volume dropped, but you can see imprints indicating more folds, and you can see cave art indicating more sophisticated culture, and more advanced tools, then you know with reasonable certainly that you're looking at a more intelligent creature despite the smaller brain.

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  • [–] 8 points 1 month ago

    Density of connections matters more than size...

    Shrinking and getting wrinkled creates more surface area, like how a shoreline will keep increasing in length the more accurate you measure it. A straight line is as short as it can be, but as you adust for smaller and smaller differences it will keep increasing until you're measuring every grain of sand and your measurement is 10,000x the straight line.

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  • [–] 7 points 1 month ago (1 child)

    You’re free to live in a cave and fight bears everyday or whatever, if you feel that is your calling.

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  • [–] 4 points 1 month ago

    I'm most states technically speaking you can't do that. The state will harass you to no end about stuff they claim is for your safety and will being but mostly they're just offended you exist without owing someone for the luxury to exist.

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  • [–] 7 points 1 month ago (7 children)

    Nah, today's world is quite complex

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  • [–] 1 point 1 month ago (6 children)

    It is complex, but the brain is stimulated to grow far more by the cacophony of the natural world than it is by the bare, low bitrate information we get from the world most inside people live through.

    The modern world caters to consciousness, which can process about 120 bits of information a second. The natural world caters to the body's sensory complex, which takes in a billion bits a second, and when you count all the information created by first-order processing, it's closer to 11 billion bits a second.

    A nervous system grows as a direct reaction to stimulus. More stimulus means more growth.

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  • [–] 3 points 1 month ago (5 children)

    Do you have a single source? Or are you just talking out your ass?

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  • [–] 0 points 1 month ago (4 children)

    These are really well studied and basic facts. I was being gracious giving consciousness 120 bits. That's the absolute limit any measurement has ever even theorized.

    https://www.caltech.edu/about/news/thinking-slowly-the-paradoxical-slowness-of-human-behavior

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  • [–] 1 point 1 month ago* (3 children)

    But your still speaking out of your ass. Cause your brain grow thing is total ....

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  • [–] 0 points 1 month ago (2 children)

    Lol wait wait wait, are y'all calling the fact that the nervous system grows as a direct response to stimulus, and neurons seek out new information sources to process, "talking out my ass"?!🤣🤣🤣

    Look, don't come asking for discussions on things you have less than a middle school education on. If you're genuinely interested, you'll have to learn the most basic of basic information yourself before we can talk about anything bigger.

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  • [–] 0 points 1 month ago (1 child)

    y’all calling the fact that the nervous system grows as a direct response to stimulus, and neurons seek out new information sources to process, “talking out my ass”?!

    JFC...Albert Einstein's brain was studied intensely, they found nothing different for any other brain. This is anal verbage.

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  • [–] 0 points 1 month ago* (last edited 1 month ago)

    Was that before or after we had the technology to map the human connectome and even the barest understanding of what all those connections could possibly amount to in a neural network?

    Keep the responses coming though, it's like watching the kid who eats crayons gloat about their special brain that gets them in special classes, calling people dumb because they "talk stupid".

    Edit: I'm sorry, I'm still dying over here at you trying to point out a postmortem brain examination from the decade before we decided to stop giving lobotomies and electroshock to cure mental problems, to bolster your opinion. So since you like images, I found you an image that shows scientists looking at Einstein's brain nearly a century ago and concluding "it look like brain"

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