On lineages (and thereby cladistics)
We distinguish entities (like mitochondria, genes, cells, organs, organisms and, perhaps, populations and species) in reality, but the notion of these entities forming “lineages” (ie, cladistics) is tricky. If every entity indeed also forms a lineage, then all lineages are also just one lineage, that is, all is one. The notion of “lineages” is thus obviously contradictory, since equalization of many with one is contradictory. This contradiction can we (at least some of us), however, accept, since lineages appears undeniable.
The question is what happens if we accept this contradiction? If indeed many can equal one, then a single entity can also equal a class of entities, eg, a single human can equal the class humans, although this is not what we accepted by accepting the contradiction that many equals one. We just accepted that both every human and the lineage of humans are lineages. The acceptance that a single human also can equal the class humans did we get on the bargain. This acceptance is what cladists call “paraphyletic groups”, “para” because it is not what cladists (actually Hennig) accepted, but a corollary to the bargain.
A possible solution to get rid of such “paraphyletic groups” is to (like cladists do and Hennig did) “deny” them, but then we have to consider what such “denial” actually accomplishes. We have actually accepted such ”paraphyletic groups” by accepting the contradiction that many equals one, meaning that we can’t deny all of them without denying our acceptance of the contradiction. Instead, we have to accept at least one “paraphyletic group” for many to equal one, that is, one. One has to be a paraphyletic group for lineages to be more than one. It means that this solution actually “denies” the acceptance of lineages itself.
At this point, the issue is so confused that we have difficulties keeping track of what we’re doing and why. We thus have to remind ourselves that our initial objective was to accept only lineages (ie, cladistics). Back on the track again, we can thus conclude that our reasoning (above) shows that such sole acceptance of lineages (ie, cladistics) is impossible. The problem is simply that many can’t equal one. This is a well-known fact in mathematics, but has obviously escaped cladists.
The consistent way to handle entities in terms of lineages is, instead, an orthogonal system like Linnean systematics. The orthogonality of this system means that it keeps entities and lineages consistently apart by using categories of classes, thereby avoiding the cladistic conflation of many with one. The compromise that comes with this bargain is that “paraphyletic groups” have to be accepted. This kind of system may be difficult to understand, but the alternative is total confusion (ie, cladistics). These two approaches are, unfortunately, the only options we have in the science of evolution. The problem is not whether evolution is a fact or not, but to hold our tongues right in our mouths to avoid contradictions, especially to avoid the fundamental contradiction that is called cladistics.
Another contribution to understanding of conceptualization http://menvall.wordpress.com/
2012-08-15 17:23:46
Source: http://menvall.wordpress.com/2012/08/15/on-lineages-and-thereby-cladistics/
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