4 ms·

I tend to be more convinced by the frugivore argument[1]. i.e. Why do primates that eat fruit tend to have bigger brains than those that eat leaves? Leaves gr

• j9461701 8y ago
  >The elephant in the room, when it comes to the social brain hypothesis, is that plenty of herd animals (or school fish) exist in massive groups without needing terribly big brains to cope. Group size and social complexity seem to be somewhat independent. Herds are a less complicated form of socialization. By contrast humans need to keep track of dozens of interpersonal relationships as a matter of personal survival. If you aren't paying attention, even the biggest toughest strongest man can be undone by 3 or 4 of his rivals banding together and attacking him as one. I'm reminded of one instance I read about several low status chimps all pouncing on an alpha who'd gotten too complacent and castrating him with their teeth, thereby ensuring he was permanently out of the running for leadership. Under such conditions, being clever is not just a nice-to-have - it is a matter of survival. The frugivore arguement might be totally valid too. As does the "natural" defense arguement - animals that have natural defenses like shells, quills, or other bodily forms of armor and defense tend to be less intelligent than creatures that lack such features. So it stands to reason that humans, as the species with the least equipped with natural defenses, would also be the cleverest of the bunch. But ultimately we just don't know. All we have is raw speculation.
• Theodores 8y ago
  I think that ants are the elephant in the room that you were looking for, they seem to have exceedingly small brains yet do live in quite large communities all over the world. The frugivore argument gets more interesting when you consider how it came to be that fruit is colour coded in the first place. Why do fruits advertise that they are ripe to eat by changing colour? Well, if you are a tree with plans for global domination than producing a few nuts for squirrels isn't going to cut it. What you really need are primates to carry your seed far and wide, to get it properly planted with some 'manure'. So, given the world was once fully monochrome, how did it happen that, as the trees evolved colour coded fruit the primates evolved colour eyesight? I blame the Blind Watchmaker. There is no god so therefore colour coded fruit could not have been specially created just for the primates. I think that it helps to have vegetarian sympathies to reject the social brain hypothesis. The idea that bigger brains are needed just to spot what fruit to eat doesn't cut it if your food is beige coloured. Imaginably we needed those bigger brains to go on the hunt and to round up woolly mammoths with spears and stuff.
  • stan_rogers 8y ago
    Think birds, not primates, if you want to try to figure out why plants colour-code seed readiness. Primates kinda suck at dispersal.
    • Retric 8y ago
      Birds also have vastly more mobility at lower time energy and risk of predation.
  • RobertoG 8y ago
    "I think that ants are the elephant in the room that you were looking for, they seem to have exceedingly small brains yet do live in quite large communities all over the world." I don't think this is a valid point. From the point of view of the genes, is not an ant colony one big organism?
• RobertoG 8y ago
  "Why do primates that eat fruit tend to have bigger brains than those that eat leaves? Leaves grow everywhere and one leaf is generally as good as another. Fruit tends to grow in specific places and ripens at different times. Primates that had to learn when and where ripe fruit would be tended to need bigger brains." A bigger brain is very energetically demanding and fruits are a lot energetic than leaves. Maybe, only primates that eat fruit can afford big brains?