Mammals: Is It Better To Be Horny or Brainy?

By Gemma Tarlach | January 10, 2017 6:01 pm
A still from a YouTube video captures the classic predator-prey faceoff: the comparatively bigger-brained lion against a horned wildebeest. Credit: Wildlife Safari TV.

A still from a YouTube video captures the classic predator-prey faceoff: the comparatively bigger-brained lion against a horned wildebeest. Credit: Wildlife Safari TV.

The arms race between prey and predator has been around since the first time one microbe evaded another; it’s a never-ending spiral of adaptations to be faster, stronger or better-defended. Now a new study looking at antipredator defenses across 647 species of mammals has found animals seem to have taken a couple different evolutionary paths to avoid being eaten. Each path came with a trade-off, however.

According to the paper published today in Proceedings of the Royal Society B: Biological Sciences, mammals evolved antipredator defenses in one of two directions: bigger brains or brawnier armor, be it horns, quills, plating, stinky sprays or grenade launchers (okay, kidding on that last one).

We’ve long known that brains are high-maintenance, or “metabolically expensive” in scientific parlance. That gray matter needs high-quality fuel and a lot of it to perform. Researchers have looked at numerous ways animals — including humans — have taken energy away from other needs to devote it towards building and maintaining ever-bigger brains.

(Although, here’s a fun fact: one of those “big brain” theories took a hit last week when a team announced they found no correlation between bigger brains and reduced tooth size in hominins, which we had long thought was the case. Hey folks, it happens. The advance of science is not a straight line, it’s a zig-zag.)

Until now, researchers hadn’t really looked closely at whether some animals evolved a different strategy for survival: devoting more energy to physical defenses and less to bigger brains.

Ponder the Pangolin

The pangolin, for example, evolved scales made of keratin all over its body — the scales clock in at up to a third of the mammal’s body mass. That kind of weight requires a lot of energy to haul around and pangolins, ah, not to put to fine a point on it, but they aren’t the sharpest crayons in the box. Armadillos, while not closely related to pangolins, take a similar approach: brawny body armor but smaller brain.

Pangolins, like this scaletastic fella at Madikwe Game Reserve in South Africa, are among the mammals that traded brains for brawny defenses. Credit: Wikimedia Commons.

Pangolins, like this scaletastic fella at Madikwe Game Reserve in South Africa, are among the mammals that traded brains for brawny defenses. Credit: David Brossard/Wikimedia Commons.

To be clear, the researchers were not simply comparing brain sizes. They used the Encephalization quotient (EQ), which plugs brain mass relative to body size into an equation to come up with a single number that can be compared from one species to the next.

Humans, for example, have an EQ of 7.4-7.8. Pangolins have an EQ of a mere 0.54 and armadillos aren’t much brainer at only 0.629.

Interestingly, when the researchers looked back in the fossil record at horn- and scale-free ancestors of several of the modern animals that do sport physical defenses, they found that most of these earlier species had higher EQs: more evidence that some animals evolved to spend energy on antipredator defenses over brains. The distant, undefended pangolin ancestor Ferae, for example, had a somewhat more impressive EQ of 1.007.

The negative relationship between EQ and defenses was statistically significant across all mammal groups.

When It Pays To Be Dumb

Why on Earth would an organism skip out on the option of a bigger brain in favor of physical defenses? The key phrase here is “on Earth.” The researchers found that the animals that seemed to be doing well with better defenses and smaller brains tended to be mid-sized, terrestrial insectivores that lived in open environments.

It’s possible that, given their lifestyle, the animals don’t need to be constantly checking out their surroundings, on guard for predators. It might make better sense for them to just do their thing, knowing that, should a predator happen upon them, it will be dissuaded from making a meal out of them after getting a faceful of barbed quills or other unpleasantries.

Ah, mon amour, some mammals, they do not need these quills or scales or other such theengs. No, no, my dear, their special, ah, parfum, is enough to keep away the beasties. Credit: Looney Tunes.

Ah, mon amour, some mammals, they do not need these quills or scales or other such theengs. No, no, my dear, their special, ah, parfum, is enough to keep away the beasties. Credit: Looney Tunes.

The Mammals In the Middle

The researchers did find an exception to the smaller brains v. better body armor trade-off: Animals that live in trees had higher EQs regardless of built-in physical defenses. The authors theorize the complexity of arboreal life, with its added planes of movement, requires higher baseline cognitive abilities than just moseying around on the ground.

Arboreal and semi-arboreal members of the porcupine and skunk family, for example, had larger brains than their grounded relatives and, in many cases, less elaborate body defenses. Arboreal porcupines, for example, have smaller and finer quills than those that are terrestrial — a logical adaptation given that the animals would have a harder time moving in the trees rocking a full set of giant quills.

The more elaborate quills of terrestrial porcupines make for a better defense, but not much fun trying to climb trees. Credit: Wikimedia Commons.

The more elaborate quills of terrestrial porcupines make for a better defense, but not much fun trying to climb trees. Credit: C-8/Wikimedia Commons.

Aside from the tree-living exceptions, the authors believe their research shows that, ultimately, well-defended species need less fancy brain matter for predator detection and evasion, and spend energy instead on their elaborate defenses.

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  • http://www.mazepath.com/uncleal/qz4.htm Uncle Al

    Welfare States are suborned by reproduction and destroyed by intelligence. If managed compassion is the law, be horny and stupid. You’ll need soldiers, for the Welfare state next door also wants escalating everything – and there is only so much stuff lying about to steal.

    The game ends when somebody plays Trump – intelligence, productivity, and Darwinian selection. 100,000 infantry are then not victory, they are a hypocenter.

    • j2saret

      But wait Trump was on welfare your argument fails from a dishonest basic premise

      • Bob Juniper

        Nice. Apply a bit of logic.

        • j2saret

          I did and pointed out the GIGO you emotionally indulged in.

          • Patricia

            While you are both patting each other on the back, I can’t help but find your thinking circuitous in the same way of that of the Nazis. Insults the bulk. Einstein thought it was so hilarious he guffawed from the balcony at a so-called debunking of “Jew” physics. Alas, another lib stupido. Lies? What earth have you inhabited in the last year? Several weeks? Where do your get your news, analysis? I have an acquaintance who says if you’re not getting it from Fox, you’re not getting the true views. A real genius.

      • Small_Businessman

        And when was Trump on welfare? Citation?

        • j2saret

          Does it matter who or what institution gives the handout? Support your answer with the scientific research not the political baffle gab.

          • Small_Businessman

            The claim was Trump was on welfare. What is the citation? I guess from your answer is there is none – it’s just another Lib lie.
            And yes, it does matter. The truth always counts. But that’s something Libs don’t care about.

          • j2saret

            I guess far more than your business is small Trump existed on un earned hand outs. That’s welfare and just as distructive as any source of unearned income and education. I stand by my assertion that the wing nut proposition exaulting trump is illogical.

          • Small_Businessman

            your proof? Itations from a reliable source? Otherwise your claims are just more Lib lies.

          • temporary guest

            Going around and around with a liberal is a lot like a dog chasing his. It’s a dizzying race that accomplishes nothing.

          • Small_Businessman

            That’s true. But when they make wild claims like these two have, they need proof of their statements. If everyone called them like this, their lies would be exposed more quickly.

          • temporary guest

            Two things I’m pretty sure of that I can’t prove:

            1) Pigs don’t know pigs stink.

            2) People who have been mentally engineered (brainwashed) don’t know they’ve been mentally engineered. Hence, they don’t know they’re lying. They just think they’re smarter than everybody else.

          • Small_Businessman

            So true. So true. It’s too bad they don’t see just how stupid they look. The only ones they are fooling is other “enlightened” liberals.

          • temporary guest

            You know what they say… Great minds think alike … and so do morons.

            LOL

          • okiejoe

            How can you tell a brainwashed liberal from a brainwashed conservative?

            Ans: You can’t.

          • temporary guest

            Sure you can. If you want to know what a conservatives’ take on an issue is, ask him “What do you think about this?”, and if you want to know a liberals’ take on the same issue, ask him “how do you feel about this?”

            Of course, there are those people who deny being either while telling themselves they’re smarter than everybody. When I run into one of those, I immediately know it’s a brainwashed liberal.

          • OWilson

            Conservatives tend to be the sketptics?

            Don’t you lockstep libs call them “deniers”? :)

          • biju

            Trump never paid taxes, he is using the infrastructure paid with taxpayers money. The greedy pig got a free ride.

          • Small_Businessman

            Your proof that Trump never paid taxes? Citations from a reliable surce, please. Otherwise this is just another Lib lie.

          • temporary guest

            I wonder how many millions of dollars the government collected in taxes from the employees who have worked either for Trump, or for contractors that he hired?

            There are two sides to every equation,

          • okiejoe

            I wonder how many millions of dollars the government didn’t collect from employees and contractors Trump stiffed.
            There are two sides to every equation, At least!

          • temporary guest

            Yada, yada, yada… if you can’t make up an accusation of your own, repeat what the other parrets say.

          • biju

            why do you think that this is fair?

          • temporary guest

            I’m not sure I understand your question. I’m 64 years old and my previous comment is 13 days old. Refresh my memory; Why do I think what is fair?

    • AlDavisJr

      Is Norway a welfare state?

    • Small_Businessman

      I guess that’s why the Libs have tried repeatedly to create a welfare state (ever since LBJ).

    • biju

      “Welfare States are suborned by reproduction and destroyed by intelligence.” Welfare states happen mostly in the south where republicans are in power. Try blaming the religious fanatics and their desire to control the brainwashed Trump is an idiot that can’t even speak in full sentences. Are you from the south???

      • evangeline

        now he is big boss, he might write a book about his presidency. Obama is more facile than Trump in the use of the American English language. Our top notch bilingual PM was Pierre Trudeau. He is fluent in both Canadian French and English. There seems to be a variation in the way English is spoken in different countries, even regions. All our PMs are bilingual, but some are better than others, but they have to have the credentials because we are bi-national, and glad of it.

        • OWilson

          What happens when you are a tri-nation, or a multi-nation?

          The print on your tiny headache pill bottles is already unreadable :)

    • Comicus

      I love when conservatives use words they do not understand in the effort to simulate intellect.

  • Analyzer_1

    Humans can have the best of both worlds, using their superior brains to augment their physical defenses as needed. On the other hand, animals with superior physical defenses cannot leverage such defenses to produce superior brains. Therefore, over the long term superior brains have an evolutionary advantage over superior natural defenses.

    • Bob Juniper

      As long as you don’t run into a tiger in the jungle. That’s his turf. Turf play a role.

      • Analyzer_1

        When on a predator’s turf, humans can augment their physical defenses with anything from body armor to an enclosed off-road vehicle. Tigers are unable to reciprocate by augmenting their brains. Humans win.

        • Bob Juniper

          This assumes humans will use their intellect. Not always the case. Bigger brain makes us lazy and over confident. There are many variables.

  • Peter Lewicke

    I don’t see it as either or. I think the ideal condition would be some physical defenses and enough brains to know when and how to use the physical. Humans do fairly well, but predators also are in good shape for physical defenses and intelligence.

  • bekindandfair

    Being horny is an unsatisfied condition. Being brainy, one is intelligent enough to achieve satisfaction.

  • Nathaniel Woods

    Welfare is not bad for those that need it. It was intended to be temporary for those that fell on hard times. However, some people decided to make it a life long way to collect income. Throw in child support, and wow! They do not need to work. Just ask my son’s mom.

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