Dan:
> > Lower animals have essentially "no" stored memories, but simply
> > process input in realtime, in the limited way allowable by their
> > limited neuroanatomy. They simply react and react and react, with
> > very little "comparison" or "reflection" to past activities taking
> > place. Some animals do have "limited" learning abilities, and in
> > those cases there is some comparison, and the amount is probably
> > graded in relation to where the animal is in the animal hierarchy.
> > ===============

Alice:
> Here I would disagree.  I have in my kitchen a water snail, been around
for over a year, who has learned to distinguish me from others in the house
and beg for food.  Snails don't like being up at the surface, it exposes
them to birds, but this snail comes up.  I recently returned from a two-week
vacation, and the silly thing came up out of the water to the  lip of the
bowl to beg.  I had the definite impression it had missed me and recognized
me when I returned.
>
> Although the thing has eyes, sort of, I believe it percieves by
sound/vibration, touch, and smell more than sight alone.


I agree that "lower" animals can have abilities which are not normally
attributed to them.
Over the years I have frequently been told that goldfish have an attention
span of under 10 seconds and can "survive" their limited environment because
of this.
I have a large outdoor tank (like a rectangular pond with a glass wall in
one end which contains a relatively small number of goldfish. At one stage,
for reasons irrelevant to this discussion,  I produced  an area attached to
the tank which contained water which heated during the day relative to the
rest of the tank. Access to this area was via a 3 dimensional path which was
not a few fish diameters wide and which had several possible entrances and
exits. Something like a simple fish maze although that was not the object.

While it was possible for the area to be discovered by "random walk" (with
or without feet :-) ) it was a fairly unlikely entrance to stumble across.

For several days after implementation no fish entered the area. Then one
fish did. Thereafter it returned daily. For quite some days (1 week plus?)
it was the only fish that did so. Then another did and then in a relatively
short period (a day or two) ALL the fish did. After that EVERY day ALL the
fish would enter the area when it was warm, spend most of the day there and
then leave when it cooled down.

It seems highly likely that

- The first fish found the area randomly.
- Thereafter it returned daily purposefully. .
- The other fish learned from the first fish.
- Thereafter they all returned daily purposefully.
- The fish preferred the warmer area.
- They chose to go to it when they knew it would be warm and left when they
knew the main tank would be more desirable.
- They develop and retain memories with spans of 1 day plus and probably
rather longer

There are still many explanations of the fine mechanism.
eg the 'following" fish may be working on sensory detection of their
fellows.
"Follow the leader" pertains - this seems unlikely as they do not do so in
the main tank.





regards,


            Russell McMahon

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