Talk:Brachycera

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Explanation[edit]

The following paragraphs are not needed on the main page... Totipotent 04:53, 18 June 2006 (UTC)

There are grave difficulties in trying to place the most recent phylogenetic classifications of Brachycera into the Wikispecies framework, as these classifications are non-Linnaean (they do not have hierarchical ranks or proper rank equivalency of sister taxa). The rank of Infraorder is where the problem is most directly noticeable: if, for example, Muscomorpha is defined (as in THE most recent trees) as the entire sister clade to the (Stratiomyomorpha + (Xylophagomorpha + Tabanomorpha)), then one is left attempting to come up with four interstitial "ranks" between the Infraorder and Superfamily levels - and something at this rank must then be declared sister to the superfamily Empidoidea. While this looks okay when drawn as a tree, it cannot be wedged into a normal hierarchy in Wikispecies (e.g., the two subgroups of "Eremoneura" - a rankless taxon - are the superfamily Empidoidea and the rankless taxon "Cyclorrhapha" - which is certainly NOT a superfamily).

The alternative is to recognize one paraphyletic Infraorder, the Asilomorpha, consisting of (Nemestrinoidea + (Asiloidea + Empidoidea)) - which is, in fact, a historically widely-used and stable taxon name - in which case the name Muscomorpha can replace "Cyclorrhapha" (since the "Orthorrhapha" is a name long-gone anyway) and the only interstitial ranks needed then are two which are already in widespread use: the Sections Aschiza and Schizophora, and the Subsections of the latter, the Acalyptratae and Calyptratae. It is admittedly a clumsy workaround, if the phylogenetic trees are accurate, but it has the distinct advantage of allowing the Linnaean Wikispecies hierarchy to remain intact, AND it makes use of names (and their constituent subgroups) in a manner that is consistent with their historical use and definitions, even if we now know that those uses are not entirely appropriate. Moreover, given the incredible rate at which new trees and classifications of Brachycera are appearing (I think there's been something like 5 different trees in the last three years), this portion of the Wikispecies hierarchy is going to be nearly impossible to maintain in an up-to-date manner. Ideally, it would be best to have a stable and widely-accepted classification, which is simply not available at the moment. Dyanega 02:43, 18 May 2006 (UTC)