Cool Garter Snake Research From Utah State University

[Cazador]

That's one problem with correlations. They help to identify general patterns, but exceptions are tolerable in their model. Still, there are a lot of examples (with exceptions) of brightly colored species being either toxic or resistant to the toxins of noxious species.

[Stefan-A]

Is that red coloration "intended" as a warning to birds in particular, or are there other predators that can see color?

[Snaky]

A very interesting video.

[Cazador]

Evolution works by chance mutations that result in appearances (phenotypes) or functions (physiology) that give the affected individual a competative advantage and allow them to survive and reproduce more efficiently that those lacking the beneficial mutation. Mutations that aren't beneficial can either be neutral or harmful, but there is no "intent" in it... only chance events that may have beneficial, neutral, or harmful outcomes. If birds use the red coloration as a warning signal, then there is a second (perhaps linked) advantage that comes with the change in the ion transporter's mutation. Beyond that, I don't know if other predators, like dogs, cats, coyotes, raccoons, etc. use the red coloration as a visual cue.

[Stefan-A]

Evolution works by chance mutations that result in appearances (phenotypes) or functions (physiology) that give the affected individual a competative advantage and allow them to survive and reproduce more efficiently that those lacking the beneficial mutation. Mutations that aren't beneficial can either be neutral or harmful, but there is no "intent" in it... only chance events that may have beneficial, neutral, or harmful outcomes.

Yes, I know that already, hence the "" around the word "intended". The word is often used in this kind of context even when the writer knows that there is no actual intention behind a mutation or other occurrence. The difference here was that I, in my opinion, acknowledged that "intention" wasn't the right word to use.

If birds use the red coloration as a warning signal, then there is a second (perhaps linked) advantage that comes with the change in the ion transporter's mutation. Beyond that, I don't know if other predators, like dogs, cats, coyotes, raccoons, etc. use the red coloration as a visual cue.

And that's what I was wondering.

[Cazador]

Hi Stefan,
Here in the U.S. there are huge misconceptions about evolution (a topic near and dear to me), so I took the opportunity to pontificate a bit. Hope you don't mind.
Rick

[Stefan-A]

No, I don't mind.

[Brian]

A couple of other fun facts about the studies at Utah State university.
1. They have bred Valley Garters (t.s.fitchi) from Utah to Red spotted garters (t.s.concinnus) from Oregon creating integrades to test how well these snakes could withstand the newt toxins. One might expect that they would have less immunity since the Valley garters throughout most of their range aren't sympatric (don't exist with) the newts. What they found was the opposite. The integrades had more immunity. One person I talked to hypothesized this may be because the valley garters eat a lot of toads (woodhouse and boreal) which both have toxins which the Valley garters are immune to and the red spotted garters have the immunity to the newts.

2. They have also produced a paper about how the garters not only are imune to this toxin but actually store it in their livers and if a bird or other predator were to eat them (and their liver) they would likely die from the toxins. They hypothesized that because of this the red may be a warning for birds. You would think then that snakes with more red would be more successfull but their are many areas in Utah and Idaho where valley garters don't have a lot of red. Perhaps these populations aren't eating the toxic toads and newts which would reinforce selective predation on the less red animals. There is no evidence that toxins are anyway related to the red on the snakes.

[Cazador]

Thanks for the update, Brian . Very cool research.