Brown relouse i think

[BrilliantEraser]

Tony I hate you and I hate that stupid website that I only just learned about now.

Okay, now that I've read up on it, my head hurts. Why/how would a snake mimic something that is more deadly while also mimicking a species that is less deadly?

Tony, if you use that website again I will track you down and kick you in the shins.

 

[Tony C]

Bring it on, I'm not afraid of a girl.













Except Robin, she scares me sometimes...

 

[BrilliantEraser]

Right. Let me just find my special shin-kickin' boots.

 

[thegeckoguy23]

Bring it on, I'm not afraid of a girl.




Except Robin, she scares me sometimes...

Haha like you said from another thread View attachment 34935 :main_thumbsup:










Jake

 

[M_surinamensis]

Okay, now that I've read up on it, my head hurts. Why/how would a snake mimic something that is more deadly while also mimicking a species that is less deadly?

Mimicking is a very long process of evolutionary selection where animals with a trait that is similar to the trait of another species with an overlapping range somehow benefits from the similarity and ends up composing greater and greater portions of the breeding population, reinforcing the existent similarities until they breed true.

Usually this is seen happening between two species or two genera and it is pretty easy to identify the type of mimicry that is happening.

The red/black/yellow banded snakes though, it happens across dozens of species in South and Central America, up into North America and the United States (although missing one of the groups in the US). So pick any two of them and you can identify a beneficial type of mimicry happening in at least one direction.

So nonvenomous species are considered a mimic of rear fanged venomous species and coral snakes under a Batesian model, they just selected for the colors and pattern because predators were avoiding anything looking like that, refining down through the generations. Tri-colored snakes weren't eaten, so tri-colored snakes made it into the breeding pool.

The rear fanged venomous and the corals are considered an example of Müllerian mimicry, both have properties that are broadly similar in defending themselves from predators and thus ended up benefiting as predators who were inclined to avoid one ended up similarly inclined to avoid the other, the same selective breeding happened- they have a similar appearance.

Looking at it by comparing the corals specifically to the Erythrolamprus (rear fanged, mildly toxic colubrid group), it is Mertesian mimicry because the corals gain an additional benefit by mimicking the less deadly species.

A highly toxic species, like the coral snakes, only really causes their potential predators to adapt on a genetic level. That is to say, anything that is inclined to try eating a coral snake (and hasn't gotten into an evolutionary arms race to prevent themselves from being envenomated) finds one, grabs it, gets bitten and dies. Which means it is not passing along those genes that made it inclined to try the coral snake as a snack. Since not every predator that avoids corals is going to be otherwise successful and not every predator that would try to eat a coral is going to encounter a coral and die- it is a long process of genetic selection that does not benefit the individual coral snakes much (since they often die when attacked anyway, even if they take the predator with them).

The Erythrolamprus can bite and envenomate and the result is quite painful but it is often not fatal to the predator. Some predatory species; mammals and birds, which are inclined to prey on snakes have the capacity to learn on an individual level. They try to eat a false coral snake, it bites them and they are in a lot of immediate pain. They don't try to eat anything that looks like that again, they adapt based on the experience immediately, rather than simply being a long term genetic selection towards avoidance, the way the coral snake model works.

So the coral snakes benefit from looking like a less toxic species and ended up selecting for the same traits that the other mimics were selecting for, there was pressure on all of the species involved to develop similar appearances. The benefit going in that direction is Mertesian mimicry.

Here in the United States, we are missing a species to fill that middle niche, the venomous but not fatal group. This either means that Mertesian mimicry is not happening here... or based on some logical guesswork and a very broken fossil chain that doesn't get enough attention to completely substantiate beyond all doubt- all our species are from groups that originated in the tropics and developed the mimicry before they spread north and began speciating.