Disclaimer: I know nearly nothing about biology. My understanding is that camouflage evolved gradually with individuals that looked more like their environment even slightly being less likely to be eaten.

I might be understanding this wrong, but it seems aposematism could not have evolved like this because you really can't distinguish slight aposematism from just being bad at camouflage.

  • $\begingroup$ @MaximilianPress are you saying there was a period of very low evolutionary pressure when aposematism evolved? $\endgroup$
    – user122938
    Commented Jul 1, 2021 at 21:36
  • $\begingroup$ @MaximilianPress aposematism is not a "bad" trait it is a direct advantageous adaptation, the question is completely valid. $\endgroup$
    – John
    Commented Jul 2, 2021 at 12:59
  • $\begingroup$ @John Fair enough, I seem to have misunderstood the original question. $\endgroup$ Commented Jul 2, 2021 at 16:44

1 Answer 1


The noxious element of aposematism evolves first.

Take a second to think about how aposematism works, you will notice the underlying mechanism works even without distinctive coloration.

Bad at camouflage means more likely to be spotted which also means more likely to be identified.

If a wolf eats a pale green frog and gets sick it is likely to avoid pale green frogs. Avoidance works by itself regardless as long as the thing doing the avoiding can identify the toxic animal, aposematism just makes it work better by making identification easier. Even if the frog is well camouflaged avoidance still works if it is toxic, but it works better if the wolves can easily tell what it is.

If the coloration is distinctive enough, or is used my several toxic organisms, predators just start avoiding that color or pattern entirely.



  • $\begingroup$ Another really interesting aspect of aposematism, from an animal behavior perspective, is that some predators seem to evolve a genetic predisposition to avoid the aposematic prey, while others still need to learn through experience. I suppose it has to do with whether the poison is deadly to the predator or simply noxious and unpleasant. $\endgroup$
    – MikeyC
    Commented Jul 2, 2021 at 16:23
  • $\begingroup$ Then there are 2 problems 1) animals that look poisonous but aren't and 2) wouldn't it take several generations to be able to look distinctive enough before you're just bad at cameoflauge? During which time you still get eaten more often? $\endgroup$
    – user122938
    Commented Jul 5, 2021 at 3:38
  • $\begingroup$ @user122938 mimicry is a separate issue, but yes is should reduce the effectiveness of aposematism. and many predators can identify animals even when they are camouflaged before they eat them, so yes you still get eaten but less often than if you were not noxious in the first place. like anything in evolution the advantage does not have to be huge to be favored. even making your camouflage worse can keep you from getting attacked as often since for many predators attack and eat are not the same action. $\endgroup$
    – John
    Commented Jul 5, 2021 at 14:34
  • $\begingroup$ But isn't not being spotted better than spotted and recognized? Since it's guaranteed survival vs not guaranteed survival. Clearly a 0% chance of being spotted is best so what you are claiming is that while 0% being spotted is best 1% chance of being spotted isn't better than 2% or 3% etc why would that be? $\endgroup$
    – user122938
    Commented Nov 11, 2022 at 2:54
  • $\begingroup$ @user122938 but a zero chance of being spotted is impossible, you still need to move around to find resources so there is no such thing as a zero percent chance of being discovered. So it is better to be avoided than risk being seen as prey, consider 20% chance to be spotted vs 30% to be spotted but 50% chance to be avoided. also evolutions is about good enough not hypothetically perfect. $\endgroup$
    – John
    Commented Nov 11, 2022 at 19:23

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