Still nobody would dispute that species level taxa do

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Unformatted text preview: n easily quantifiable pattern of morphological d ivergence not only argues strongly for the notion that specia tion is ‘not’ an ‘event’ of an inherently specifiable kind, but a lso for the parallel fact of life that a comprehensive definition o f species – like the identification of a unitary ‘mechanism’ of s peciation itself – will always remain out of reach. Still, nobody would dispute that species-level taxa do exist i n some meaningful way. Nature really is packaged, however u ntidily; and those boundaries actually are there, no matter how b lurry or elusive they may be. It is, of course, because they a ccept this unavoidable reality that the advocates of the PSC s o fervently desire some simple and effective operational way o f recognizing species. Yet the simple fact is that nature does n ot always organize itself for the taxonomist’s convenience. It is at this point that Paterson’s RCS enters the picture, w ith its focus upon how conspecifics mutually recognize that t hey belong to the same exclusive breeding pool. From Paterson’s perspective, the significant thing is that the subjects of o ur studies know perfectly well who they are, irrespective of h ow difficult it may be for us to ‘read their minds’ on the matter. A ccordingly, he emphasized the importance in species recog nition of inter - individual signaling systems, whether vocal, or c hemical, or behavioral, or visual (Paterson 1985). Sometimes c andidate signaling systems may mislead human observers, a s in Madagascar they evidently have done in the case of the s everal easily recognizable varieties assigned to the E ulemur f ulvus g roup. By Mittermeier et al.’s (2010) last count, there are s even species in this group. All are differentiated by marked c hromatic differences in the pelage, and some of them are a dditionally sexually dichromatic. They are certainly diagnos able, at least in terms of mean chromatic tendencies. But since a lmost all of these purported species readily and successfully i nterbreed when given the opportunity, and almost anyone who h as wandered extensively in the forests of Madagascar has o bserved f ulvus - g roup variants that defied ready classification, t he distinguishing features that are so evident to us clearly have l ittle to do with these lemurs’ own senses of identity. Similar o bservations also apply, if less dramatically, to certain other l argish - bodied diurnal lemurs, such as some variants of the P ropithecus verreauxi - g roup (e.g., King et al. 2012). Different problems apply to the categorization of the t ypically smaller - bodied and more cryptically colored nocturnal forms. Between them, the two genera M icrocebus a nd L epilemur a ccount for a large proportion of the recent increase i n the number of lemur species: in 1982 there were two species o f M icrocebus a nd only one of L epilemur ( albeit with six subspe cies); while in 2010 the respective counts were 18 and 26, respectively. Most of these purported sp...
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This test prep was uploaded on 03/31/2014 for the course ARH 102 taught by Professor Leslie during the Fall '08 term at SUNY Stony Brook.

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