Real Species

[pierre deleporte]

A 16:35 23/04/2004 +0200, vous avez écrit :
>Pierre Deleporte:
> > Hence "contemporaneous" is as important as "spatially connected" for
> > defining an individual, or a looser system. A real, observable one, not a
> > human thought construct. Real things out there are contemporaneous and
> >spatially related
>
>I suspect that going consequently this way, the concept of "individual" 
>will disappear at all. "Spatially connected" is a matter of scale, hence a 
>pretty subjective thing. Is a table individual? And two tables laying one 
>on another?

Ok, proximity is not connection. Two pigs sleeping abbutted on one another 
don't make an individual.
But may I suggest that we keep talking only of biological individuals, and 
not of other objects (as tables are)?

>The same is true for "contemporary" - if you are observing a man's breast, 
>you do not see the back and vice versa - obviously you depends on a belief 
>("theory") that the other side is still existing when you are not 
>observing it... (sorry for this simple example - more sophisticated 
>extensions are welcome ;-)

I completely agree that even our daily trivial "observations" are 
theory-loaded some way. Recall Popper "this is a glass of water" 
(implicitly involves a "theory" of glass, and one of water).

But here is where scientific realism is important (see Nico Mario Franz 
recent post for developments on this). We believe that there is a back 
behind the chest, and that our observation of the chest ilmplies the 
existence of a connected back. Of course we better verify, but scientists 
like checking and re-checking, particularly systematicians.
So I see no difficulty here for distinguishing an observable self-coherent 
concrete individual from a human-conceived class of living objects.

>Even more this is true for "processes" (you are quoting mutation, 
>selection...) - provided the only "real things" are those 
>observed/contemporary ones, only the "state A" or "state B" can have some 
>"reality" but not the process of change A->B (say, mutation).

OK, we really have access to what we check now, plus the more or less 
reliable record of the (even very recent) past states of the system we 
observe. I remember arguing this way with Niles Eldredge, that there is a 
difference of degree, not of nature, between the interpretation of the 
historian, and that of the experimenter. We never, ever, have access to 
anything else than a more or less complete and reliable record of the past, 
except our glance at the ever fleeing instantaneous state of affairs.
This said, there is still not the slightest problem for differentiating and 
individual (Curtis) from a set of individuals (human species).

>In such a way, we are coming to the conclusion that all we have are only 
>perceptions and mental constructs based on them (classes, concepts, 
>theories etc.). This is nothing bad - that's only old'n'good nominalism 
>(in many flavours). I believe that this conclusion is even inevitable when 
>one tries to consequently apply formal reasoning (logics, mathematics) to 
>""real"" world - that is, unavoidable path of the science (in its present 
>form at least). We only should be consequent and either (1) develop 
>another concept of "real thing" than observability/spatial configuration 
>or (2) avoid the concept of "real things" at all.

Agreed overall, but I'm not the first guilty of proposing "real" = 
"observable", and then "real" = "natural", neither to say that a species is 
as "real" (anyway you like it) as an individual.
A species is simply not an individual. Call it as you like, it's a diffrent 
thing. What a human being decides to put in the same class is not equal to 
a concrete system. It may be the same, and may not.
If I say that Curtis is an individual, and that the collection of all human 
beings living, dead, interacting or not, is an individual, well, let's 
forget "real" if you like, but what would be the definition of 
"individual"? Something real, that you cannot divide, or rather that is not 
divided. I think "individual" should mean a highly cohesive system at least.

If you call human beings past, present (and yet to come, by he way, why 
not) an "individual", please provide me with a different name to call what 
I am, myself as a unique human being rather biologically self-cohesive 
(without cro-magnon I mean; he is dead, you know; I don't really feel like 
biologically cohesive with the poor man...). I don't even belong to the 
same population as cro-magnon, do I? How can I belong to the same individual?


>Best regards!
>Zdenek Skala
>skala at incoma.cz

My very best ones,
Pierre


Pierre Deleporte
CNRS UMR 6552 - Station Biologique de Paimpont
F-35380 Paimpont   FRANCE
Téléphone : 02 99 61 81 66
Télécopie : 02 99 61 81 88