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Author Topic:   Evolution of Poison
Spencer
Inactive Member


Message 16 of 21 (243647)
09-15-2005 1:28 AM


I was watching the discovery channel one day and they were discussing these extremely poisonous salamanders. The big question the scientists were pondering was how did these salamanders become so deadly? They later discovered that a specific species of snake was hunting these salamanders for hundreds of years. Over time, the snake grew immunity to the salamandar's poison. This in turn caused the salamander's poison to become more potent and the cycle continues. The snake still eats these extremely poisonous salamanders because it has a pretty good immunity towards them. After eating them, they don't die, they are merely paralyzed for a few hours from the effects of the poison.

Replies to this message:
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riVeRraT
Member (Idle past 860 days)
Posts: 5746
From: NY USA
Joined: 05-09-2004


Message 17 of 21 (243771)
09-15-2005 10:03 AM
Reply to: Message 15 by Nuggin
09-15-2005 12:13 AM


Re: Snake venom
Yes, I understand. I don't even really have a problem with evolution. I guess it is possible that we were created to evolve.

But due to the gaps in evolution, it makes me wonder.
Ever see a bacteria flagelum?

I look at it like this sometimes. We were created in his image. That means we probably do things similar to him. When we build things, we go in succession, starting from the simplest to the more complicated.

Either way that is not why I believe in God. God made himself known to me in a very powerful way. either that or I am nutz.


This message is a reply to:
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riVeRraT
Member (Idle past 860 days)
Posts: 5746
From: NY USA
Joined: 05-09-2004


Message 18 of 21 (243789)
09-15-2005 10:31 AM
Reply to: Message 15 by Nuggin
09-15-2005 12:13 AM


Re: Snake venom
Yes, I understand. I don't even really have a problem with evolution. I guess it is possible that we were created to evolve.

But due to the gaps in evolution, it makes me wonder.
Ever see a bacteria flagelum?

I look at it like this sometimes. We were created in his image. That means we probably do things similar to him. When we build things, we go in succession, starting from the simplest to the more complicated.

Either way that is not why I believe in God. God made himself known to me in a very powerful way. either that or I am nutz.


This message is a reply to:
 Message 15 by Nuggin, posted 09-15-2005 12:13 AM Nuggin has not yet responded

  
Cal
Inactive Member


Message 19 of 21 (243819)
09-15-2005 11:30 AM
Reply to: Message 16 by Spencer
09-15-2005 1:28 AM


Spencer:

I was watching the discovery channel one day and they were discussing these extremely poisonous salamanders.

The poison found in in the granular glands of newts of the family Salamandridae is especially toxic, and was given the name tarichatoxin after its isolation in western newts of the genus Taricha. Tarichatoxin is biochemically identical to the water soluble alkaloid tetrodotoxin (anhydrotetrodotoxin 4-epitetrodotoxin, tetrodonic acid), or TTX, the third most potent non-protein neurotoxin known to exist. Upon entering the blood stream, TTX blocks the sodium channels of excitable membranes, causing paralysis in the nerves and muscles.

Tetrodotoxin is found in Japanese pufferfish and in several other poisonous animals including globe fish, sun fish, trigger fish, blue-ringed octopus, frogs of the genus Atelopus, seastars, xantid crabs, horseshoe crabs, numerous marine snails, flatworms, and sea squirts, with more species still being discovered.

It is thought that the toxin is acquired through the food chain from TTX-synthesizing bacteria. Through natural selection, pufferfish and other animals possessing TTX took advantage of a single-point mutation in their sodium channel that rendered them immune from the toxin. This enabled them to consume and adapt the poison to their systems without experiencing any ill repercussions.

http://www.livingunderworld.org/amphibianArticles/article0011.shtml

In other words, for these animals, evolving the ability to use these toxins required only the aquisition of resistance to toxic elements already available in their environments.

The big question the scientists were pondering was how did these salamanders become so deadly? They later discovered that a specific species of snake was hunting these salamanders for hundreds of years. Over time, the snake grew immunity to the salamandar's poison. This in turn caused the salamander's poison to become more potent and the cycle continues.

Many of the sophisticated adaptations we observe (the speed of the cheetah, for example, or the camouflage of stick insects) seem best explained as the results of this sort of 'arms race'. But there are other big questions, such as: "are bacteria of the genus Vibrio really the source of TTX in salamanders; if so, how exactly do the amphibians aquire it; and how exactly do the bacteria produce it?"

The snake still eats these extremely poisonous salamanders because it has a pretty good immunity towards them. After eating them, they don't die, they are merely paralyzed for a few hours from the effects of the poison.

In my youth, I was (regretably) often willing to injest substances which could easily be regarded as 'poisonous', with the express intent of achieving a similar effect. I now limit my deliberate intake of toxins to caffeine, with the express intent of counteracting a paralysis which, as I get older, seems more and more to be my natural, unmedicated state.

This message is a reply to:
 Message 16 by Spencer, posted 09-15-2005 1:28 AM Spencer has not yet responded

  
Nadine
Inactive Member


Message 20 of 21 (260940)
11-18-2005 12:01 PM
Reply to: Message 8 by riVeRraT
08-09-2005 10:37 PM


Re: Snake venom
Well, it's not all that difficult. For example, one particular toxic component (seraphotoxin) in a snake venom is derived from a peptide hormone that regulates heart function in vertebrate animals (endothelin) . All these animal produce the hormone in minute amounts. However, if you get an overdose, it makes your heart fibrillate, which will kill you (Heart fibrillation is the condition which is treated with an electric shock to the chest in an emergency room). If, for example with the help of a so called transposable element (jumping gene), a copy of this gene was moved into the place of a gene for a protein produced in a salivary gland, this simple mutation would render the bite of the animal highly toxic, even without the complex poisen fang apparatus modern venomenous snakes possess. Since the toxin is a protein, it is only toxic when injected into the blood stream, in the digestive track it gets degraded. Thus one single mutation copying a gene into a different context on the chromosome gave it a different function, further evolution then refined the delivery process. Other components of snake venoms derive from other genes, which similarely have benign function in the snakes metabolism, but are toxic when injected into your bloodstream through a snake bite. That's an example of the process which kongstad meant with "gene recruitment". It did not need the slow evolution of a harmless protein to a toxin, the simple effect of overproducing a particular normal protein (a peptide hormone) in a particular place (the salivary gland), that is, to copy and paste a particular piece of DNA from one place into another, changed its function.

This message is a reply to:
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RAZD
Member (Idle past 345 days)
Posts: 20714
From: the other end of the sidewalk
Joined: 03-14-2004


Message 21 of 21 (261117)
11-18-2005 8:01 PM
Reply to: Message 1 by Wolf
08-03-2005 4:22 AM


Welcome to the fray Wolf.

and have not been able to find how organisms evolved poison.

Are you aware that plants also engage in toxic warfare? Many plants are toxic to consume of course, but there are also plants that emit toxins into the soils to poison the ground to other plants, thus ensuring more nutrients are available for its own growth.

And you don't need to look far to see one: oak trees. (ever wonder why you can't grow good grass under oaks?) it's called Allelopathy.

http://www.sustland.umn.edu/implement/trees_turf.html

Enjoy.


we are limited in our ability to understand
by our ability to understand

RebelAAmerican.Zen[Deist
... to learn ... to think ... to live ... to laugh ...
to share.


This message is a reply to:
 Message 1 by Wolf, posted 08-03-2005 4:22 AM Wolf has not yet responded

  
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