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I think the preceding sentence in that paragraph answers it. Important context here is that garter snakes tend to swallow prey whole. tldr: a strongly poisoned
by calebkaiser 1y ago
I think the preceding sentence in that paragraph answers it. Important context here is that garter snakes tend to swallow prey whole. tldr: a strongly poisoned newt survives consumption attempts.
> And it explains why the newts keep evolving to be more toxic: the snake may want to eat newts generally, but if an individual newt packs enough of a wallop, the snake may just retch it up and go after a different one. Newts with weaker poison? They get eaten. Snakes with less resistance? Have trouble finding newts they can choke down, and don’t get to steal their poison. So the arms race continues.
- thaumasiotes 1y ago> Snakes with less resistance? Have trouble finding newts they can choke down, and don’t get to steal their poison. That's got to be an extremely weak effect. No snake gets an individual benefit from eating the newts. They get a collective benefit, that predators recognize the species as poisonous, in which all snakes, poisonous and delicious alike, share equally. The problem is large enough that actually-poisonous animals routinely have delicious mimics of entirely different species who free-ride off of the work the originals do to be poisonous. You can't explain why snakes apparently need to avoid sending a dishonest signal with a theory that predicts that mimics don't exist.
- calebkaiser 1y agoYeah that particular aspect of his claim feels like the weakest. Here is a slightly more in-depth piece where a wildlife biologist mentions other possible forcing functions that cause the snakes to eat the newts: https://baynature.org/2022/04/06/the-bay-area-is-the-center-of-an-evolutionary-race-between-hungry-snakes-and-toxic-newts/ https://baynature.org/2022/04/06/the-bay-area-is-the-center-... From the article: > “When garter snakes are born in the late summer, they often live under mats of drying pond vegetation … That happens to be where the newly metamorphosed newts come out in the fall, and we suspect there could be a lot of interaction between predator and prey just because of this overlap in microenvironment. That could have led to strong selection in the past that resulted in such high levels of resistance.”
- darkerside 1y ago> The problem is large enough that actually-poisonous animals routinely have delicious mimics of entirely different species who free-ride off of the work the originals do to be poisonous. When cargo culting goes right.
- thaumasiotes 1y agoYes, if supply planes couldn't tell the difference between military runways and cult runways, cargo cultists could lure them in and... depending on their defenses... overpower the pilot and take all the stuff.
- the_af 1y agoInteresting. Let me see if I follow: once the snake population has the warning coloration, and predators know not to eat them, then individual snakes being successful at eating poisonous newts is unrelated to the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection). So a snake which has the right colors will be successful, regardless of its diet. I wonder, is there a point where mimicry can fail? Can predators at some point start to eat the mimics?
- catlifeonmars 1y agoI suspect that as the number of mimics increases (either an individual species or convergent evolution of mimicry, like we see with the number of insects with bee or wasp-like coloration), the relative risk of consuming things that look poisonous drops to a level where it’s sustainable for a population of predators. To your point I wonder if eventually some truly toxic species can become a victim of their own success
- thaumasiotes 1y ago> Let me see if I follow: once the snake population has the warning coloration, and predators know not to eat them, then individual snakes being successful at eating poisonous newts is unrelated to the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection). So a snake which has the right colors will be successful, regardless of its diet. Sort of. Whether the snake is poisonous is unrelated to its success, because it dies upon being eaten whether there are consequences to its predator or not. (The article takes some pains to show that this is untrue of the newts, but not the snakes.) However, > the snakes living long enough to pass their genes (i. e. being successful in terms of natural selection) This does not reflect a good understanding. Success means having more children, not having any children.
- the_af 1y ago> This does not reflect a good understanding. Success means having more children, not having any children. I never said "any children", so your remark doesn't reflect a good understanding of what I wrote. Try not being pedantic for pedantry's sake, and engage with a question asked in good faith without playing games of one-upmanship.