death cap & Gliriform mammals

[Dave Jefferies]

My understanding is that in one sense the ability of rabbits to eat A.
phalloides should not be seen as toleration. The toxin is bound in a cyclic
peptide. It is only when the molecule is broken down that the toxic fragments
are created. I am not sure whether this  implies that they are small enough to
pass the stomach barrier into the blood, and that the whole molecule would also
be toxic, or if only the fragments are toxic. I will check Benjamin's recent
book on fungal toxins to see if that gvves a lead.

However far more interesting is this:
Is the molecule fragmented by secretions from the human stomach or is it split
by the action of the gut flora? When we start to look at the human being as an
ecosystem (I remember from one microbiology lecture that there are ten times as
many non-human cells on a human body as there are human cells within it) life
gets interesting.

Should we look at an organism, or more importantly groups of organisms at both
the species and at higher levels, as supplying the necessary conditions for
other organisms, that are themselves closely (or should that be functionally)
related? The ability of organisms to function is at least moderated by their
symbionts (using the word in the broad sense). How this affects a taxonomic view
I will leave to others.

Dave Jefferies

Ken Kinman wrote:

>      I would be interested to know if this ability to tolerate the Death Cap
> is restricted to taxon Glires (rodents and rabbits).  A possible
> synapomorphy of the group???
>                    ------Ken Kinman
> *********************************************************
> >From: Robin Leech <robinl at CONNECT.AB.CA>
> >Reply-To: Robin Leech <robinl at CONNECT.AB.CA>
> >To: TAXACOM at USOBI.ORG
> >Subject: Re: Adam's apple
> >Date: Thu, 6 Apr 2000 20:02:28 -0600
> >
> >Also eaten by squirrels, mice and a few other animals.
> >Robin Leech
> >----- Original Message -----
> >From: "Dave Jefferies" <D.W.Jefferies at SHU.AC.UK>
> >To: <TAXACOM at USOBI.ORG>
> >Sent: Thursday, April 06, 2000 6:16 AM
> >Subject: Re: Adam's apple
> >
> > > Not quite to the question but ...
> > >
> > > I have heard that Amanita phalloides, the Death Cap, is very tasty. It
> >can of course be eaten with impunity by rabbits. Some other edinle fungi
> >should be
> >cooked and contain heat labile toxins.
> > >
> > > Tasting good is likely to be a function of the sugar content. Other
> >chemicals in the fruit may affect different species in different ways.
> > >
> > > Dave
> > >
> > > veldkamp wrote:
> > >
> > > > Dear All,
> > > >
> > > >         Someone put forward the following proposition: Any fruit that
> >tastes good
> > > > must be safe to eat.
> > > >
> > > >         My question: does anyone out there know of an apparently
> >deliciously
> > > > edible fruit that will poison and sicken or kill those who eat them?
> > > >
> > > >         Obviously excluded are fruits like grapes, olives,
> >strawberries,
> >etc. to
> > > > which some people are allergic.
> > > >         Borderline cases are Taxus baccata, where the 'flesh' is quite
> >edible, but
> > > > the 'kernel' very poisonous, and Blighia sapida, where there is a red
> > > > membrane between the lobes of the quite edible lobes of the aril.
> > > > Beech-nuts (Fagus silvatica), when eaten in high quantity are reported
> >to
> > > > make you ill because of minute cyanide contents. I never found enough,
> > > > apparently.
> > > >         Also excluded is Cycas cicrcinalis, cause of the Guam disease
> >leading to
> > > > dementia, paralysis, and death.
> > > >         What I'm looking for is the bang-you're-dead (or ill)
> >situation,
> >a bit
> > > > like what the apple did to Adam and Eve, or Sleeping Beauty.
> > > >
> > > > JeF
> > > > Dr. J.F. Veldkamp
> > > > National Herbarium of the Netherlands, Leiden Branch
> > > > POB 9514
> > > > 2300 RA Leiden
> > > > The Netherlands
> > > > e-mail: veldkamp at nhn.leidenuniv.nl
> > > > fax: + 31 0715 27 35 11
> > >
> ______________________________________________________
> Get Your Private, Free Email at http://www.hotmail.com