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Science

Peer Pressure Forced Whales and Dolphins To Evolve Big Brains Like Humans, Says Study (qz.com) 99

An anonymous reader quotes a report from Quartz: The human brain has evolved and expanded over millennia to accommodate our ever-more-complex needs and those of our societies. This process is known as "encephalization" and has given us the big brain we need to communicate, cooperate, reach consensus, empathize, and socialize. The same is true for cetaceans, like whales and dolphins, it seems. These sea creatures also grew big brains in order to better live in societies, according to a study published on Oct. 16 in Nature Ecology & Evolution. According to Michael Muthukrishna, an economic psychologist at the London School of Economics and co-author of the study, the researchers used two related theories, the Social-Brain Hypothesis and the Cultural-Brain Hypothesis, to make predictions about various relationships between brain size, societal organization, and the breadth of behaviors the cetaceans would display. Then they tested these predictions by creating and evaluating a comprehensive database of cetacean brain size, social structures, and cultural behaviors across species using data from prior studies on 90 types of whales and dolphins.

The study found that cetaceans had complex alliances and communications, played and worked together for mutual benefit, and could even work with other species, like humans. Some also have individual signifiers, sounds that set them apart from others, and can mimic the sounds of others. In addition, it found that brain size predicted the breadth of social and cultural behaviors of these marine creatures (though ecological factors, like prey diversity and latitudinal range, also played a role). The researchers concluded there was a tie between cetacean encephalization, social structure, and group size.

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Peer Pressure Forced Whales and Dolphins To Evolve Big Brains Like Humans, Says Study

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  • Man, I *knew* this pressure they put on us to publish on well-ranked peer-reviewed academic journals was bad for health. My head hurts so much, it's going to explode!

  • by Anonymous Coward

    The size of the brain doesn't seem to matter so much anymore.

    I see some logic vs Lysenkoism at play here..

    • Re: (Score:2, Insightful)

      by Anonymous Coward

      But insects aren't really social. They form big colonies, but they predominantly act as a large group of individuals acting for the good of the group. There's no concept of social relationships between individuals in an insect colony.

      Humans don't do the big picture stuff as well, but we can maintain unique relationships with up to about 150 other humans or animals (Dunbar's number). Whales, dolphins, and also elephants and many primate species seem to do the same.

      • by mikael ( 484 )

        Insects just follow a set of rules that their genes have programmed with. Everything from communication to building nests. The fun experiments scientists did was to work with solitary bees/wasps when they were building nests. Simply changing the shape of the nest as the critter flew off to get more building materials would put them back into whatever state their programming instructed them to do. If a clay nest was basically an upside down pot, then closing off the bottom would make them start a new stalk a

  • Dolphins? (Score:5, Interesting)

    by mentil ( 1748130 ) on Tuesday October 17, 2017 @11:45PM (#55387899)

    My understanding is that dolphins' large brains are mostly glial cells [wikipedia.org], which are there to keep their brains warm, rather than actual neurons. That's why their brains are so large yet they're only about as intelligent as dogs. Correlations made with dolphin brain size may not end up being very meaningful.

    • by lucm ( 889690 ) on Wednesday October 18, 2017 @12:38AM (#55388015)

      Did you read the Wikipedia article you posted?

      When markers for different types of cells were analyzed, Einstein's brain was discovered to contain significantly more glia than normal brains in the left angular gyrus, an area thought to be responsible for mathematical processing and language.

      So I guess we're fucked if a dolphin gets access to matlab or excel.

    • Brain size isn't going to be directly correlated with intelligence, whatever intelligence is...

      Evolutionary pressure for intelligence without matching pressure for small brain size may cause the brain to grow, as the quickest route to increased intelligence by chance mutation, but... if there is pressure on brain size and intelligence at the same time, that should eventually lead to brains that are simultaneously smaller and smarter.

      Look at what the brain of a wasp can do... pound for pound, the brains of f

      • Insect brains are indeed miracles of scaling and situational reuse.

        Primates have our own interesting mutation on that front: Normally cell size scales with body size - an elephant's cells are far larger than a mouse's, including it's neurons. So brain-to-body size ratio provides a reasonable first-order approximation of intelligence across species.

        Primates though have evolved roughly constant-size neurons, so that large primates have far more neurons than small ones, even when the brain-to-body size ratio

      • Evolutionary pressure for intelligence without matching pressure for small brain size

        Brain tissue is physiologically expensive. There's your pressure for small brain size.

        That it requires glucose to fuel it (instead of the mix of glycogen and fats which muscle cells can absorb in addition to glucose) adds to the physiological stresses produced trying to run a large brain.

        I'm now wondering how large a brain (mammalian) can get before it can't lose heat sufficiently to avoid permanent heat stroke. Elephant

  • by careysub ( 976506 ) on Tuesday October 17, 2017 @11:51PM (#55387915)

    It is clear that high intelligence is not necessary for successful survival, there is no general trend toward progressively evolving high intelligence in any lineage on land but the Hominidae (and it stalled among all the branches of the Great Apes but one). Curiously modern humans 80,000 years ago went through a near extinction event, with the world population dropping to a few thousand individuals, intelligence equivalent to our own did not give them a huge survival advantage at that time.

    But success in a society creates an intelligence arms race. More powerful brains processing social information give an edge in dominating reproduction opportunity through most of evolutionary history. (Debates about whether perhaps the opposite is true at this moment in history I leave aside.)

    • You're using environmental activist thinking.

      Intelligence is not needed for your species to "survive" if what you mean by that is existing in vast numbers over long periods of time. But show me the cockroaches with the social structure and self-awareness it would take to figure out its place on the planet and in the solar system, learn that a large asteroid is a hundred years away from destroying all life on Earth, and use that time to find out how to deflect it.

      THAT's how I would define survival.

      • You're using environmental activist thinking.

        I'm not sure what that means. But you're using a fundamental misunderstanding of evolution.

        Intelligence is not needed for your species to "survive" if what you mean by that is existing in vast numbers over long periods of time.

        First, evolution doesn't favor species survival, or individual survival. It favors genetic survival, meaning the survival and replication of a genotype over competing genotypes. In many cases, the best genotype survival adaptations are adaptations that favor the survival or growth of the species, or the individual, but that's a side effect -- and doesn't always happen. Sometimes the adaptation that enables one genotyp

        • To put it slightly differently, for social animals, evolution is driven by the survival of tribes or packs, not the survival of individuals. That's why wolf packs do just fine with only the alphas breeding, and why evolution hasn't eliminated homosexuality.
          • To put it slightly differently, for social animals, evolution is driven by the survival of tribes or packs, not the survival of individuals. That's why wolf packs do just fine with only the alphas breeding, and why evolution hasn't eliminated homosexuality.

            Not quite. Even in social animals, genes are ultimately "selfish". It's not about individuals or species. But it's definitely the case that in social animals the beneficial (to the genes) adaptations are often related to the ability to cooperate for the good of near-relatives, as well as the good of direct replication.

        • Allow me to clarify 'environmental activist thinking' for you: because Greens assign no value to human civilization or indeed intelligence itself, they like to think that the most successful species on Earth, in terms of long-term survival, is something like the cockroach, which in their view is morally equivalent to humanity and deserves fully equal rights.

          What I just demonstrated above is that human intelligence, and with it division of labor, the ability to cooperate on tasks, to store information as a s

          • your ideology supports as being the highest moral standard

            Why are you claiming I hold that bizarre belief?

            FWIW, to the degree I'm interested in environmentalism, it's merely to keep it relatively nice for people to live in. I couldn't care less about cockroaches, except to the degree that they contribute to my quality of life, and I don't really think that they do. I do kind of like having other plants and animals around; many are useful, many are interesting, some are just plain cute. But that's really neither here nor there, because my comment had nothing to d

      • What does it mean for a species to "figure out its place on the planet and in the solar system" and are you so sure that any species has done so?

        Cockroaches have survived asteroid impacts before. Even if they could deflect one, why would they bother? And are you so sure that any species is capable of doing so?

        • Cockroaches can survive a wide variety of environmental changes because they are simple, stupid, and rugged. But there's a limit to what they can withstand because they have never evolved an ability to understand their place in the universe around them. Humans have, which allows us to envision and eventually protect against, plagues, volcanic upheavals and natural climate changes.

          Of course our power to save ourselves is at any given time limited because we don't understand the whole universe. But precisely

    • by Solandri ( 704621 ) on Wednesday October 18, 2017 @06:16AM (#55388751)
      I test nearly autistic, so I had to figure out a lot of the complex rules of social interaction, instead of it being "obvious" like I guess it is to most people.

      As an example, my sister gave me a birthday present which I didn't really need. I thanked her (learned that rule pretty early), but told her I didn't really need it. She knows about my social handicap, so explained to me that when you receive a gift, you're supposed to politely accept it whether or not you really want it.

      Some years later, a friend gave me a gift which I didn't really need. But remembering what my sister said, I thanked her, politely accepted the gift, and tucked it away in the trunk of my car. Where it sat because, well, I didn't really need it. A few months later the friend saw the gift in the trunk of my car and was livid and upset. She bawled about it to a mutual friend, who came and talked with me about it. The mutual friend said I should've just declined the gift if I didn't want it. I explained what my sister had taught me, and she took a deep breath, and said "yes that's true, but not in this situation."

      That day I learned that the rule my sister taught me has an exception. If someone gives you a gift because they like you, accepting it is a sign of being open to reciprocating. And if you're not interested in the person, you're supposed to politely decline the gift as a signal that you're not interested. (Though I'm still a bit unclear how you're supposed to know that the gift is a "like" gift when the person doesn't actually say so when they give it to you.)

      Social norms are full of these rules, exceptions to the rules, exceptions to exceptions, exceptions to exceptions to exceptions, etc. It takes quite a bit of brainpower to figure all this out subconsciously so that it's "obvious" without having to learn it the way I have to.

      And to point out the elephant in the room, there's another behavior which demands social conformity and also has these complex rules and exceptions, thus requiring a bigger brain. Language.
      • by Anonymous Coward

        That day I learned that the rule my sister taught me has an exception. If someone gives you a gift because they like you, accepting it is a sign of being open to reciprocating. And if you're not interested in the person, you're supposed to politely decline the gift as a signal that you're not interested. (Though I'm still a bit unclear how you're supposed to know that the gift is a "like" gift when the person doesn't actually say so when they give it to you.)

        I don't think I'm autistic (at least not much, I am on slashdot), and I would never refuse a gift for any reason (unless it were clearly attached to an obligation, in which case that's not a gift anyway). I guess my point is it's not cut and dry. If someone gave me something I didn't need or want, I would at least hide that fact from them haha.

      • by Anonymous Coward

        This anonymous coward on the Internet would like to offer a few social lessons that might help you.....

        1) Non-autistic people are not automatically social adepts. Each one is full of a unique collection of social failings, and misunderstandings. They will often state rules that directly contradict one another. Sometimes it is because they are living out the relevant details that distinguish the situations, but other times it is because they are too steeped in the emotion of the moment to consider the sit

      • Your story has nothing to do with being autistic. Everyone makes mistakes by misreading social situations from time to time.
      • by urusan ( 1755332 )

        I'd say your sister's rule should be the default rule, and you should only deviate from it if you're very confident it's an exception, since it's socially much safer to accept a gift than reject it (as you point out, you can't always tell the difference between these scenarios). You should only turn down a gift if you realize there's something attached that you don't want (for instance, they "like" you and want a deeper relationship you're not interested in, they are bribing you, etc.). The best indicator t

    • >world population dropping to a few thousand individuals, intelligence equivalent to our own did not give them a huge survival advantage at that time.

      This seems like a reach. If there was such an extinction event, high intelligence and social cooperation are an adaptation to environmental pressure. It drastically improves the odds of not only surviving but rebounding to support a large social group quickly, leading to the very apparent intelligence arms race you point out during successful times.

      I don't

    • Those near extinction events were quite likely selection processes for intelligence. Sure, smart people died due to circumstances, but when the circumstances were bad enough that only the smart people lived...

      Smart people and dumb people have remarkably similar looking brains under post-mortem dissection, fMRI scans, and all kinds of other analyses... how can we possibly infer anything about intelligence from fossilized remains?

  • Splain that! (Score:3, Insightful)

    by Tablizer ( 95088 ) on Wednesday October 18, 2017 @12:01AM (#55387935) Journal

    I have a relatively big brain, but I'm socially clueless.

  • by OYAHHH ( 322809 ) on Wednesday October 18, 2017 @12:33AM (#55388005) Homepage

    Could have sworn I saw a humpback whale staring for hours at an IPhone the other day.

  • by swell ( 195815 ) <jabberwock.poetic@com> on Wednesday October 18, 2017 @01:59AM (#55388223)

    If they keep getting smarter they may become as smart as octopuses. Brain size isn't everything. Until recently, the largest human brain ever measured was that of an idiot. Albert Einstein's brain reportedly weighed slightly below average at 1.23 kg.

    • by Anonymous Coward

      the motion of the ocean is what matters

    • by mentil ( 1748130 )

      Evidently the brain stores information as zeroes, pecking holes in the gray matter.

  • So long, and thanks for all the fish!
  • While in humans it appears to be working in the opposite direction.

    • Actually... yes. There has been a small but steady decrease in average brain size in homo sapiens for some time now. (http://discovermagazine.com/2010/sep/25-modern-humans-smart-why-brain-shrinking)

      Either our brains are getting more efficient or they're shedding unnecessary redundancy or functionality. I'd tend to believe the latter since that would be the simpler change in evolutionary terms.

      Keep in mind there's no need to translate the above to the belief we're getting less intelligent. There are proba

  • How do we know the larger brains don't cause the more complex social interactions, rather then the complex social interactions like peer-pressure causing the brain to grow? Correlation doesn't equal causation. I'm no psychologist, but the cause and effect seems reversed here - small brain, no peer pressure to cause the brain to grow in order to create peer-pressure, no?

    • Because of how natural selection works... what you're describing is more like Lamarckism
      • I see. By that logic, computer engineering is practiced only by the homo sapiens which has the most evolved brain, therefore we can conclude that computer engineering is the cause homo sapiens brain evolvution?

        • No... perhaps I was too succinct. Being better at complex social interactions conferred selective advantage, which led to positive selection for the traits (larger brains) that allowed for more complex social interactions.
  • ... would you just go grow and a big brain too?

    Honestly, Jonny, I just don't know what to do with you.

    - Whale Mom, ages past

    • If my friends larger brains were helping them get laid, then yes, damn right I would grow a larger brain too! (No, that's not quite how evolution works, but you get the point.)
  • You don't need large brains to have a good time!

  • Large brains aren't necessary for survival. Large brains only help with social competition. If your success at breeding is predicated on your success in social competition, then you evolve complex intelligence just to compete. This rule would apply to most highly social animals, so of course cetaceans and primates. What we think of as "status" is just another word for "fitness to breed", that's why humans crave high status so much -- it literally increases their chances of getting laid.
  • most the brain of whales is devoted to sensory perception, that's been long known and the reason why the intelligence of whales is comparable to certain animals that are not primates.

Human beings were created by water to transport it uphill.

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