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Date: Thu, 26 Jun 2003 21:21:35 -0700 (PDT)
From: "Jaime A. Headden" <qilongia@yahoo.com>
To: PhyloCode@ouvaxa.cats.ohiou.edu, dinosaur@usc.edu
Cc: david.marjanovic@gmx.at, darren.naish@port.ac.uk
Subject: Re: AFROTHERIA, CROWS & SPECIES CONCEPTS
David Marjanovic (david.marjanovic@gmx.at) wrote [to the dinosaur mailing list]: <Great. Let's take this to the PhyloCode mailing list (which hasn't had any traffic for months) and argue against any ruling about species in at least the first version of the PhyloCode, which is after all about clades. :-)> Well, not definitions of a species, per se, but in defining hominid genera, Camilo Cela-Conde and Frasisco Ayala (2003) suggest a four genus rule in Hominidae, dumping a lot of new genera, on the basis of so-called "adaptative criteria"; these were defined by Mayr (a stauch opponent to cladist theory and phylogenetic taxonomy); quoting Cela-Conde and Ayala (pg. 7686): "This evolutionary and ecological concept of the genus leads to identification of three hominid genera, corresponding to three distinctive adaptative zones: (i) Australopithecus, encompassing the first hominids that gradually developed bipedalism; (ii) Paranthropus, the evolutionary branch (incorporating the robust australopithecines) that colonized the open spaces of the savanna with specialized feeding on hard vegetables; and (iii) Homo, the branch that evolved large brains and retained from Australopithecus gracile features, used stone tools, and developed a more carnivorous diet." Though Cela-Conde and Ayala review cladistic definitions of hominids and Hominidae, and concepts therein they fall on the side of Mayr and regard various paraphyletic, adaptation-based groups of hominids: Hominidae Sahelanthropus tchadensis Praeanthropinae Praeanthropus (including Orrorin, and Australopithecus species afarensis and portions of africanus, bahrelghazali, anamensis and garhi) Ardipithecus ramidus Australopithecinae Australopithecus (including boisei, robustus, africanus, and aethiopicus) Homininae Homo (including Pithecantrhopus, Kenyanthropus, Protanthropus, Sinanthropus, Cyphanthropus, Africanthropus, Telanthropus, Atlanthropus, Tchadanthropus ... I'm-gonna-hurt-my-fingers-anthropus ...) Cela-Conde, C.J. & Ayala, F.J. 2003. Genera of the human lineage. _Proceedings of the National Academy of Sciences, Philadelphia_ 100 (13): 7684-7689. If this would be applied, any set of given features can be used to define what is and is not a taxon, and the authors are clear in stating their collection of names and lumping is based on what they consider to be "excessive genera" for hominids, as if they should be reasonably smaller, and are loathe to explain why, or how many other extant -idae taxa have much more complex species arrangements and referrals (to which Mayr devoted his early career in South-East Asian birds to document). While the authors rightfully question the neccessary assignment of such ambiguous taxa as *Orrorin* and *Sahelanthropus* to Hominidae or to reflect the origin of bipedalism and the gracile face of moderun human development, they include them nonetheless, at no odds with including *Orrorin* as a species of *Praeanthropus* along with rightfully upright, bipedal "man-apes" such as *A. afarensis* ("Lucy"). Though the paper is opf some historical interest, this would serve as a caution: checks and balances are absent, this is a do as you will systematic treatment and does not question or even cast doubt on a cladistic treatment, just stating the adoption of Mayr's adaptive treatment in perspective and practice. The overcomplication and rather ... unique ... perspectives on all parts of the field of hominid systematics may be a brush fire waiting to happen and maybe that would be the best and most ideal candidate to test PT on, given a specimen-based phylogenetic and cladistic treatment. The authors above, for instance, discuss the often overlapping or contradicting anatomy of many African specimens in regards to species identification, arrangement of populations, diagnosis of "genera" on the basis of single specimens, even if they are more complete than the hypodigms of several well-recognized australopithecine taxa (including *A. boisei* = *Paranthropus*). --- Thanks to Mickey Mortimer for making this appreciated paper available to me Cheers, ===== Jaime A. Headden Little steps are often the hardest to take. We are too used to making leaps in the face of adversity, that a simple skip is so hard to do. We should all learn to walk soft, walk small, see the world around us rather than zoom by it. "Innocent, unbiased observation is a myth." --- P.B. Medawar (1969) __________________________________ Do you Yahoo!? SBC Yahoo! DSL - Now only $29.95 per month! http://sbc.yahoo.com