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> On 15/09/2011 10:32 AM, Stephen wrote:
>> On 15/09/2011 9:24 AM, Invisible wrote:
>>> I'm just wondering whether fungi deliberately manufacture substances for
>>> no other reason than to prevent them being eaten,
>>
>> Do you believe in a god?
>
> *sigh*
>
> OK, well if you want to split hairs...
>
> I'm just wondering whether the fact that many fungi are poisonous to
> large mammals is positively selected for, or a neutral trait.
In some cases, it's a survival advantage.
In other cases, it's neutral and offers no real advantage. There may
have been a time when it WAS an advantage to protect it from some, now
disapeared, harmfull organism.
>
> (Which is /obviously/ what I asked in the first place, to anybody who
> actually understands how evolution works.)
Yes, over very long time periods and countless individuals. Advantagous
traits leads to higher survival rate and more offsprings. Disadvantagous
traits leads to earlier death and less offsprings.
>
> The tea tree manufactures caffeine for no reason other than to control
> pests. It is of no "use" to the plant itself, it's just poisonous to
> certain insects that try to eat the plant. If there were no insects, the
> tree wouldn't need to make caffeine at all. This is "deliberate toxicity".
Nothing deliberate here.
A pland had a slight random mutation and started making caffeine. By
chance, it killed some insects that where eating the plant, and some
times killed it. Maybe those insects also eated the seeds of flowers,
reducing the number of offsprings.
That plant chances of survival thus increased, leading it to have more
decendents.
Similar to the production of vitamin C by plants. It protect them from
some infections. It's actualy toxic to some fungi and bacterias.
>
> Other substances, however, are manufactured as part of an organism's
> internal metabolic processes. As hormones, as intermediate compounds, as
> storage, whatever. A few of these just happen to be toxic to other
> species. This is "accidental toxicity".
>
> None of this is intended to imply /actual concious intent/. It's just a
> figure of speech. Sheesh...
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On 15/09/2011 9:14 PM, Alain wrote:
>> On 15/09/2011 9:24 AM, Invisible wrote:
>>> I'm just wondering whether fungi deliberately manufacture substances for
>>> no other reason than to prevent them being eaten,
>>
>> Do you believe in a god?
>>
>
> In fact, not at all!
Nor do I.
But you did not ask if fungi deliberately manufacture substances for...
--
Regards
Stephen
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On 9/15/2011 1:24 AM, Invisible wrote:
> On 15/09/2011 03:38 AM, Patrick Elliott wrote:
>> On 9/14/2011 6:24 AM, Invisible wrote:
>>> Are fungi poisonous on purpose, or is it just a side-effect of their
>>> unusual body chemistry?
>>
>> Nothing is "poisonous on purpose", everything is a side-effect of
>> different body chemistry. It just happens that, in some cases, those
>> side effects make them a lot bloody harder for other things to eat.
>
> OK, but consider this: The venom of the Black Widow spider is "designed"
> to be lethal to insects - and indeed it is. To mammals, it's harmless.
> It has no effect on dogs, cats, mice... oh, but by freak coincidence, it
> happens to be deadly to humans. How unlikely is that?
>
> Point being, humans aren't the target. It just happens to work on them.
> Insects are the target.
>
Designed no. But if your a spider and you can't produce poison that
effects insects, its not going to help you much. That some of them
happen to accidentally effect other species, is not coincidence, in that
you need the same chemical processes, on some level, in all animals. A
poison doesn't have to do the same "identical" thing, hence the lack of
some having an effect at all. In other cases, it may do some of same
things, but because the poison isn't effecting the nervous system, but
some other effect (spider venom also has necrotic effects, which kill
tissue, regardless of *whose*, because it breaks down cells chemically,
without needing to target specific characters "of" those).
A good example is snakes. Snakes have a very complex cocktail of organic
chemicals. In most of them, those have been adapted to shut down pain,
in most of the prey they go after. Since humans are not "prey", *none*
of them should have a chemical for that. Yet, there is one in Africa,
which does, and its not a python, or anything that might logically eat
people. But... it might have eaten monkeys, of some sort or another, and
a chemical that targets some nonspecific characteristics of pain
receptors in monkeys "might" by sheer accident also effect humans, do to
commonalities in the two nervous systems.
In any case, a "designed" venom wouldn't need 40+ different, often
redundant, organic chemicals, instead of 3-4 very specific ones. They
wouldn't need to contain things that have no effect on their prey, at
all, but effect things, in some cases, that they would *never* come in
contact with, etc. There are a lot of cases like that. Adaptations,
which while they don't stress the animal enough to lose them, are nearly
useless, because what they once affected is no extinct locally, and
others where the effect of the adaptation actually is worse for other
species, than the one it targets. Why? Because it works well enough for
what its used for, and the coincidence that its much worse for something
else is accident. Snakes don't "intend" to kill people, but some of them
*will*, because we have the misfortune of happening to react **very
badly** to their venom. It makes about as much sense to ask why this is
the case, as though it was "designed", as to ask why some flowers
produce pollen, which *happens* to make some percentage of people *very*
allergic.
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On 9/15/2011 10:14 AM, Orchid XP v8 wrote:
> And that's what I'm asking. Is mammal predation on fungi significant
> enough that it's worth developing defences against it? Or is the extreme
> toxicity of some fungi merely an unrelated accident?
>
Since we don't eat all sorts of them, but just the larger ones, I would
say, "probably". At the very least, wild pigs eat them, and probably
others too. Besides which, that they have the characteristic, and its so
heavily involved in their chemistry at this point, doesn't mean that the
species that they *did* have a risk from is still present. After the
trait exists, it merely needs to have "some" limited benefit, or not
cost more than getting rid of it, to continue.
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Am 15.09.2011 21:32, schrieb Orchid XP v8:
>> Are lay people warned to...
>>
>> a) not eat self-collected fungi that have a certain well-known look, or
>> b) not eat /any/ self-collected fungi unless they're /absolutely/ sure
>> of what they are?
>>
>> Is this because...
>>
>> a) the toxic species of fungi are so few that they can easily be
>> described and remembered, or
>> b) the toxic species of fungi are too many to be easily described or
>> remembered?
>
> How about
>
> c) Most of the toxic species have no known antidote and are usually
> very, very fatal.
>
> People are also advised to drive at 30 MPH in areas where people live,
> even if there are no people there.
>
> Alternatively,
>
> d) Most fungi actually look pretty similar to each other, and you need
> specialist equipment to tell them apart.
Note your use of the word "most" here, implying a significant number of
toxic fungi in both cases, hence indicating that a) can be ruled out at
any rate.
That aside, AFAIK c) is not true (only few fungi must be classified as
"very, very fatal", at least in the sense of being frequently fatal even
with good medical care), and neither is d) (I've never heard of any
toxic fungi that need specialist /equipment/ to distinguish them from
any edible species of fungi; AFAIK, the most that is required is a good
deal of attention to visual details, and of course profound knowledge
about the similarities and differences between edible fungi and their
toxic look-alikes).
(Disclaimer: I Am Not A Fungi Expert, so don't rely on the above.)
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On 9/14/2011 6:24, Invisible wrote:
> In a similar way, if I wanted somebody to go to an empty field and just
> *build* me a house, what would that cost?
That's pretty easy. Look at your homeowner's replacement cost insurance.
--
Darren New, San Diego CA, USA (PST)
How come I never get only one kudo?
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On Thu, 15 Sep 2011 14:00:44 -0400, Warp wrote:
> Jim Henderson <nos### [at] nospamcom> wrote:
>> Evolution *is* *not* *design*. Not even remotely.
>
> Evolution is emergence.
Yes.
> OTOH, it also depends how exactly you define "design".
The verb "to design" implies one who designs. "Design" is not
"emergence".
Jim
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On Thu, 15 Sep 2011 19:13:45 +0100, Orchid XP v8 wrote:
>>> Which is /obviously/ what I asked in the first place, to anybody who
>>> actually understands how evolution works.
>>
>> When you start throwing around the word 'design', you start
>> demonstrating a lack of understanding of how evolution works or even
>> what it is.
>>
>> Evolution *is* *not* *design*. Not even remotely.
>
> *sigh*
>
> Yes, and when I say "Word 2003 doesn't understand files saved by Word
> 2010", I do not for one minute intend imply that Word is actually a
> concious, thinking, comprehending entity. Of course I *know* that Word
> is merely a construction of op-codes, a sequence of instructions blindly
> executed by a mindless automaton, an inanimate machine. I know that
> there is no "thinking" or "understanding" involved. IT'S A FIGURE OF
> SPEACH!!!
>
> Sheesh...
It's not a figure of speech, it's an inaccurate statement that those
proponents of so-called "intelligent design" latch onto like leeches and
say "see, see, there IS a creator!"
Jim
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>> Yes, and when I say "Word 2003 doesn't understand files saved by Word
>> 2010", I do not for one minute intend imply that Word is actually a
>> concious, thinking, comprehending entity. Of course I *know* that Word
>> is merely a construction of op-codes, a sequence of instructions blindly
>> executed by a mindless automaton, an inanimate machine. I know that
>> there is no "thinking" or "understanding" involved. IT'S A FIGURE OF
>> SPEACH!!!
>>
>> Sheesh...
>
> It's not a figure of speech, it's an inaccurate statement that those
> proponents of so-called "intelligent design" latch onto like leeches and
> say "see, see, there IS a creator!"
And I really don't care if those fools want to purposely misunderstand
me. They aren't my intended audience.
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On 16/09/2011 03:23 AM, Darren New wrote:
> On 9/14/2011 6:24, Invisible wrote:
>> In a similar way, if I wanted somebody to go to an empty field and just
>> *build* me a house, what would that cost?
>
> That's pretty easy. Look at your homeowner's replacement cost insurance.
Isn't that just the cost to buy another already-existing house of a
similar type?
Though come to think of it, presumably /building/ a house will always be
more expensive than merely /buying/ one, so that gives us a lower bound
on price...
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