> In reality, fruits usually contain (some) toxins for a number of
> reasons, as follows.
> 1. To protect from insect attack, before the fruit ripens.
> 2. To differentiate which species eats the fruit; i.e. to promote fruit
> consumption by the animal(s) that are optimal seed dispersal agents,
> and to discourage consumption by other animals.
My question would be: would you happen to know whether some toxins have
been identified in (ripe) fruits that are commonly used by humans, like
apples or mangoes (these fruits are supposedly suitable for
consumption by mammals).
> 3. To control how much of the fruit is eaten by the optimal seed dispersal
> agent, at each sitting.
That's what anopsologists call the "instinctive stop". Fruits contain
chemicals that make its taste/texture unpleasant when eaten in
excess. A typical example is that of pineapples, that contain
bromelain. But, as far as I know, bromelain is not toxic (it even has
> 4. Once the seed is deposited in a dung pile and sprouts, toxins may
> serve as natural fungicides, and to protect the sprout until it is
> able to produce its own defensive toxins.
Okay, but the toxin is in the seed, not in the flesh, so these toxins
are easy to avoid.
> * Virtually all foods contain substances that, in isolation and in large
> quantities, are toxic. Even water, in huge doses, may be toxic; after all,
> people have committed suicide by drinking water.
I don't know how you commit suicide by drinking water, but I think
death results from mechanical, not chemical reasons, so water can't be
qualified as "toxic" (you can die from a car crash, but the reason of
your death is not the toxicity of cars). A better example than water
would be that of vitamins, some of which are harmful in high doses (we
then talk of "hypervitaminosis").
--Jean-Louis Tu <[log in to unmask]>