Real Species

[SKÁLA Zdenek]

From: pierre deleporte [mailto:pierre.deleporte at UNIV-RENNES1.FR]
> A species is simply not an individual. [snip]
> 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.

Well, a ("natural", not "taxonomic) species *is* cohesive and *is* interacting. At least, here is only a negligible difference between the (many) species and populations. Anyway, the concept of "connection" or "interaction" as something (roughly) spatially and temporally close is indefensible, IMHO. Any communication have a temporal dimension (the signal needs to be sent before it is received; the time lag between these two events is a pretty quantitative thing). Consequently, I would argue that hereditary and generally parent-offspring relations (including cultural phenomena, BTW) are a kind of connection/interaction and so qualify even dead members of a lineage as parts of a species.
Any individual has its history and would we call the dead parts as "members" or "traces" or anything is really playing with semantics only. The only important thing here is that the current individual (Curtis, Zea mays...) is the same individual as was 10 years ago. Speaking about dead cells or fossil plants we are mismatching the whole (a man, a species) with its parts (no matter if dead or living).

pierre:
> 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?

Here is some misunderstanging, probably. You, Pierre, are an individual (I believe!); the Homo sapiens *can* be individual, too - simply individuality can be hierarchically arranged. Your body cells (or some of them at least) have some kind of individuality and own life cycle but know very little about Pierre. The same is true in the direction single plant - Zea mays (not to be personal :-)

pierre:
> I completely agree that even our daily trivial "observations" are 
> theory-loaded some way. [snip]
> 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.

The individual/class distinction is more a matter of the angle of view than of what is in "reality". With a huge simplification: we can class all the Zea mays plants according to some set of characters (and we get a "taxonomic species") or we can see it as an interacting whole (and we get a "natural species" see above for the historical aspect of interaction).

To summarize: I am not saying that species (or even all species) are individuals; only that the arguments of Pierre are not very relevant to this problem - sorry.

Best to all!

Zdenek Skala
skala at incoma.cz