Dear Art,

A saying in the Netherlands is that "one crazy person can ask more
questions then 100 wise men can answer". (This is certainly not intended as
an insult!)
At present, your questions cannot be answered, and it might take longer as
expected, because a lot has to be taken into account, and many data have to
be correlated. I will try to give an example.
In the Netherlands there is a species of mouse. Research has revealed that
in one tooth (!) there are three possible forms of one ridge (I hope this
is the correct term).
Further investigation revealed that the three different form have slightly
different ecological niches: one lives on clay bottom, the other on sand,
and the third one peat like bottoms. (I don't know whether breeding
experiments between these populations have been undertaken).
So, what are these mice? Species? Subspecies? Ecomorphs? Ecosubspecies?
Within Carabidae (a family of predatory beetles) some species are
recognised by the presence/absence/position of one (!) hair on the tarsi
(part of the legs).
Within Chortippus (a genus of grasshopers) in the Netherlands there five
species are recognised. They can be recognised by the number of thorns on
their hind legs, and by their "songs". They do not interbreed, females of
species A are not attracted by the songs of the males of species B to E,
and so on. However, going into southeastern direction (towards the Alps)
differences become less conspicuous, and once arrived in the Alps, the
species cannot longer be seperated by counting thorns and listening to
songs.
Currently, research is done on a very common ant in the Netherlands. It
seems to occupy a number of habitats, and the number of hairs on them
differs.
As far as I remember it was within the Pyrenees (mountains between France
and Spain) that there is a valley with some side valleys. In the main
valley there lives a species of land snail. It can interbreed with
specimens from the side valleys, no problem. The specimens from one side
valley do not and cannot interbreed with the ones from other side valleys.
And this is only species level........
I think that we forget one thing: we want to catagorise to much (me too),
and tend to forget that evolution exists, and that it is happening right in
front of our noses, and that during these processes (although I believe
that species exist) one cannot always pinpoint an exact moment when
"something" has become a different species.
Several years ago, a species of Strombus (Conomurex) was described from the
Mediterranean. Suddenly it was there, out of the blue. It was subsequently
described as S. decorus raybaudii. Subsequent research revealed that it was
nothing more as S. persicus. Wait a moment.
Within a given population there is genetic variability, this may express
itself in phenotypic variation (you see it every day when you look at your
family, or just walk out the front door). Suppose that the conditions in
the Mediterranean are slightly different from those in the Persian Gulf. It
could be that a certain variation (could be a lot of things: colour
pattern, size of shell, size of operculum) has advantages in the
Mediterranean. These would have more success in producing offspring, and
this offspring may have, let's say, a larger operculum. Suppose that
decrease of the number of serrations on the operculum is also an advantage.
There is a possibility that within a number of years the population in the
Mediterranean has specimens with a large operculum with less serrations.
What is this? A new subspecies? A new species? (and that is skipping the
problem of the name it should have).
And then suppose that more changes come: a high spire is an advantage in
the Mediterranean, losing the Stromboid notch also........What do we have?
A new (sub)genus?
I can't tell you, and I am afraid that no one can.

Gijs



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> Van: Art Weil <[log in to unmask]>
> Aan: [log in to unmask]
> Onderwerp: Re: Olivellidae??
> Datum: zondag 29 augustus 1999 1:02
>
> Dear Gijs and Paul;-
>         I understand the problem I have proposed. If it were not a
significant
> problem, someone would have solved it a long time ago. All I am saying
> is that science has taught us that there ARE trends, solutions, etc. And
> electronics has taught us that solutions can be quantified.
>         Simplification of questions:
>         1. How many points of difference and of what quality are needed
to
> diferentiate Species?
>         2. How many points of difference and of what quality are needed
to
> diferentiate Genera?
>         3. How many points of difference and of what quality anr needed
to
> diferentiate Families?
>         We (a very collective WE) should be able to come up with some
sort of
> formula.
>         As for me: I can tell the difference between a Tulip and an
Elephant.
> ---but it took some study.
>         Art Weil