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The impossible predicament of the death newts

crookedtimber.org

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Re: The impossible predicament of the death newts

#151

Post by fc417fc802 »

odyssey7 wrote: post #138
mattigames wrote: post #107

Earlier quoted context omitted.

This is categorically false, we know evolving bigger brains required us to reduce our muscle mass compared to other primates, for the energy budget required to create such brains.

That cost and benefit trade-off emerged as an opportunity only through luck and it survived only through luck, even if the odds were in its favor.

Biased random walk and luck are related but not the same thing. It is not necessarily correct to term the outcome of a stochastic process as luck.

Re: The impossible predicament of the death newts

#152

Post by catlifeonmars »

mekoka wrote: post #115
pegasus wrote: post #109

Earlier quoted context omitted.

That resistance to toxins we don't encounter often enough to constitute selective pressure, we carry around only if it's the accidental byproduct of another selected-for trait. Otherwise entropy would take care of it, sooner or later. Parent is right, evolution doesn't pay an annual subscription fee for some service which was useful in the past and might come in handy in the future.

You may just be trying to disagree with the author for sport. > we carry around only... Not true. We can carry resistance to some ancestral pressure which isn't part of the current environment. > sooner or later... Yes, sooner when it's costly, later when it's less so, through normal evolutionary pressure (entropy and all). The point is, most species at time T do carry traits that aren't that useful to them anymore.…

It would be interesting to see how toxic these newts would remain if the garter snakes were eradicated. If this was indeed a costly trait, we should see a drop in toxicity over a long period of time (possibly evolutionary time). To rule out coincidence, you could follow multiple lineages as they speciated.

In fact, looking at related newts whose ancestors were toxic (assuming the trait is not novel in these ones) would give us some idea as well.

Re: The impossible predicament of the death newts

#153

Post by catlifeonmars »

mattigames wrote: post #141
mr_toad wrote: post #139

Earlier quoted context omitted.

Do we know that? I thought that the evidence suggested that early hominids lost muscle mass, especially in our arms, as they came down from the trees. We also switched from stronger muscle fibres to high endurance muscles. You’re right that there was an energy trade-off, but it was being able to run faster and longer that was more important than strength for our ancestors, who still had quite small brains (the brain…

The diminished muscles in our jaws are one of the direct causes we have bigger brains, source: https://www.newscientist.com/article/dn4817-early-humans-swa... Humans evolved Wesker muscles to gain brain mass, source: https://www.nationalgeographic.com/culture/article/140527-br...

From the first article:

> Humans owe their big brains and sophisticated culture to a single genetic mutation that weakened our jaw muscles about 2.4 million years ago, a new study suggests.

_A new study suggests_

I don’t think you can treat these claims as categorically true. It’s plausible and probably warrants further study, like most things in biology.

Edit: I could not read the second article you linked as it was behind a paywall, but I found the full text of the original paper[1]. The paper appears to make a much weaker claim: that a weakening of jaw muscles in humans coincided with acceleration in brain size. This is certainly intriguing, but correlation does not imply causation.

[1]: https://pmc.ncbi.nlm.nih.gov/articles/PMC4035273/

Re: The impossible predicament of the death newts

#154

Post by catlifeonmars »

the_af wrote: post #145
thaumasiotes wrote: post #37

Earlier quoted context omitted.

> 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 a…

Interesting. 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 po…

I 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

Re: The impossible predicament of the death newts

#156

Post by thaumasiotes »

busterarm wrote: post #40
steezeburger wrote: post #38

Earlier quoted context omitted.

I don't think they had MSG before salt

Who cares? We don't live "before salt". Human use of salt _predates writing_ by about 3000 years. You wouldn't choose to do manual typesetting (or copying books by hand!!!) today either versus alternatives. If you're _just_ looking to add umami flavor to a dish today, you'd be crazy to pick foraging for wild mushrooms over Aji no Moto.

> Human use of salt _predates writing_ by about 3000 years.

That looks like... an intensely conservative estimate. Deer use salt.

Re: The impossible predicament of the death newts

#158

Post by pegasus »

mekoka wrote: post #115
pegasus wrote: post #109

Earlier quoted context omitted.

That resistance to toxins we don't encounter often enough to constitute selective pressure, we carry around only if it's the accidental byproduct of another selected-for trait. Otherwise entropy would take care of it, sooner or later. Parent is right, evolution doesn't pay an annual subscription fee for some service which was useful in the past and might come in handy in the future.

You may just be trying to disagree with the author for sport. > we carry around only... Not true. We can carry resistance to some ancestral pressure which isn't part of the current environment. > sooner or later... Yes, sooner when it's costly, later when it's less so, through normal evolutionary pressure (entropy and all). The point is, most species at time T do carry traits that aren't that useful to them anymore.…

In the context of TFA, are you sure it's not GP who's arguing for sport? Maybe this clarifies the issue: one way to reword the root (critical) comment is "of course there is a cost, since entropy is always exacting a price". There's constant upkeep necessary for any trait if it is to be preserved. It points out a glaring blind-spot in the article.

Re: The impossible predicament of the death newts

#159

Post by thaumasiotes »

the_af wrote: post #145
thaumasiotes wrote: post #37

Earlier quoted context omitted.

> 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 a…

Interesting. 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 po…

> 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.

Re: The impossible predicament of the death newts

#160

Post by thaumasiotes »

darkerside wrote: post #131
thaumasiotes wrote: post #37

Earlier quoted context omitted.

> 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 a…

> 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.

Yes, 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.
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