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Is it the case that if I was to develop an alien world that the most likely outcome would be that the animal in the middle of the food chain is going to be the one that is most likely to develop intelligence?

Edit: Are there reasons why a low level animal would gain intelligence? What about higher predators?

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    $\begingroup$ ...um...we did...well, sort of... STOP STARING! $\endgroup$ – nzaman Feb 28 '17 at 16:53
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    $\begingroup$ It seems plausible, at least. An apex predator has little to no advantage to gain from becoming more brainy. Brains need fuel. Lots of fuel. So why develop a bigger one if you already have life cut out for you? $\endgroup$ – Burki Feb 28 '17 at 16:54
  • $\begingroup$ Wolves, Lions and Orca whales are social apex predators, and socializing is one of the purposed paths to intelligence. It seems like the are more places in the middle of a chain than at the top or bottom. $\endgroup$ – user25818 Feb 28 '17 at 17:52
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"Middle" is a pretty broad term when it comes to a food chain. Here on earth it would describe anything between modern humans and plankton. So most likely the answer is yes... But that's not fun, so let's look a little deeper.

Most species that are commonly recognized as intelligent are social, most are carnivorous or omnivorous and most are mammals. Notice that I said "most" quite a few times there. There are a few notable exceptions like the cephalopods, which aren't mammals or particularly sociable.

Brains are hungry things which require a lot of calories, in most environments that means eating your fellow creatures, at least occasionally.

Bigger brains usually need time to grow, develop, and train which means that mammals get a bit of an advantage due to lactation and hence attention/protection from a parent.

Which brings us to the social component. Animals the have bigger brains often have longer adolescent periods, which means that they aren't fully self sufficient, thus they need protection, food, and so on. Animals that can rear young cooperatively get a significant advantage because they can leave the crumb-snatchers with the neighbors while they hunt and forage.


It's not uncommon to see "higher level" predators gain some higher intelligence. See dolphins, wolves (pack hunters in general)

It's also not uncommon to see "lower level" omnivores gain some higher intelligence. See raccoons, monkeys


As for the notable exceptions... We're still not sure why cephalopods have evolved to be as apparently intelligent as they are. Some seem to think it may be due to sexual selection, female cuttlefish seem more likely to select males that are smart enough to disguise themselves to sneak by the larger stronger males.

So... If you're working on intelligence in an alien world, just make it sexy and things should progress pretty well...

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Regarding your question about animals lower down the food-chain developing intelligence, I want to present you Alex. Although Grey Parrots sometimes eat insects, they are generally frugivorous - eating fruits, seeds and the like. Still they show remarkably intelligence, matching the level of apes in cognitive tests. The following reasons are brought forward to explain their intelligence:

  • living in variable environments
  • highly social
  • huge forebrains
  • extended developmental period and extended life span

This list is based on this paper: Cognitive ornithology: the evolution of avian intelligence and can be used to explain the development of animal intelligence in general.

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It reminds me of the old Douglas Adams joke about dolphins.

Let's define "intelligence" as an improved mental capacity that has given a species an evolutionary advantage – it must effect the birth / survival rate of the species or it doesn't play a role in their evolution.

By that standard some of the things we consider a hallmark of higher intelligence (philosophy, rocket ships) aren't actually contributing to population growth, but medicine and microbiology have lead to child-immunization causing the population to boom and society to diversify. This creates opportunity for genetic evolution in all directions, not just intelligence (consider poor eyesight, deafness, allergies, and other genetic "defects" that are no longer severe handicaps thanks to technology).

But the impact of technology is not always straightforward. Genocide and war kill millions but presumably there are winners whose genetics supplant the losers. And counter-intuitively, birth control leads to healthier children who live longer, and stronger cohesive families due to mothers surviving childbirth and helping to raise their own grandchildren. It's not always about quantity. In both these cases it's about the allocation of resources to fewer survivors.

We use to believe that intelligence meant the use of tools and advanced engineering, but now we've observed so many animals creating tools and building complex structures it hardly seems special anymore. We are starting to recognize animal intelligence in more subtle ways, like their understanding of physics, language skills, social fairness, and the ability to empathize with what others are experiencing. Any of these might have a daily impact on survival.

Some types of intelligence we recognize in the animal kingdom (that aren't top predators) include:

So to get back to your question, any mid-foodchain creature that is using its wits, memories, or social skills to avoid being eaten, store food, and raise healthier children can be considered to have evolved intelligence.

As to the last question about top-predators, the same rules apply. Some predators benefit from social intelligence and co-operative child rearing, and even use co-operative physics to hunt, but other top-predators are loners who hide their vulnerable babies while hunting and hope for the best. Some top-predators are their own worst enemies, for example lions where the females live co-operatively but the males are responsible for most infant mortality, and this article talks about the fallacy of confusing the survival instincts of the individual with the survival of the species.

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I think that "mid-food chain" is the lowest you can probably go. For one thing, it takes time and learning for intelligence to aid survival. It takes time for the previous generation to pass the survival knowledge on to the younger generation.

I don't think that low-food chain animals would live long enough to be able to do that. In fact, the lower in the food chain you go, the more creatures seem to be adapted toward: mature quickly and breed lots. They tend to use hardwired instincts to bypass the learning curve that more intelligent creatures use.

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