Posted by:
WW
at Tue Oct 26 06:33:06 2004 [ Report Abuse ] [ Email Message ] [ Show All Posts by WW ]
>>Hi CKing,
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>>6. ideology. A proposal based on ideology is most likely accepted by those who share the same ideology and rejected by those who have a different ideology. For example, taxonomists who split a species because of his/her subscription to the evolutionary species concept will generally find acceptance among adherents to the same concept but rejection by those who subscribe to a different species concept.
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>>That's exactly the point!
>>Ideologies always seem to ignore facts and knowledge. Things that were right once (and perhaps still are) are simply ignored or being argued.
A lot of what is blamed in "ideology" is simply due to the fact that our ways of thinking about evolution have changed, partly as a result of the diveristy of different tools that we have available. When things like the BSC were being formulated in the mid 20th century, reproductive isolation and morphology were pretty much the only sources of evidence that were available to researchers. Today, we have access to a much greater variety of tools, which give us access to different types of information, particularly phylogenetic information. I would argue that it would be very sad and worrying if these new tools and new insights had NOT affected the way we view the natural world and classify it.
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>>7. fashion. A proposal to split taxa, for example, on the basis of phenetic differences is much more likely to be acceptable to most biologists when phenetics was fashionable, as it was during the 1970's. A phenetic classification is much less likely to be accepted today, since cladistics is fashionable.
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>>Same here! Are phenetic characters nowadays inevident or do "modern" taxonomists only accept finding based on what they call "state of the art" methods?
Two points here:
First, phenetic methods continue to be employed for things like describing patterns of geographic variation, diagnosing species limits etc., which they do very well. Phenetic methods are rarely used above the species level because classification here is normally based on phylogeny, which phenetic approaches cannot recover.
Second, the phenetic vs. cladistic dispute is not about whether the methods are "state of the art" (as far as technique goes, both approaches can be as simple or as sophisticated as you like), but on the philosophical basis of what we are trying to reflect in classification. Cladists wpuld argue that since there is only one true phylogeny, we should attempt to reflect that in classification. This has become the most widely accepted view in systematics, whether one likes it or not.
Cheers,
Wolfgang
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