[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: vultures and musophagids




<<<Anyway, in regards to Ron's statement that most workers think that vulturids are derived ciconiids is not really true. Yes, Sibley and Alquist have presented much molecular evidence and it is generally accepted that vulturids are storks, but not everyone is willing to say so. Cracraft has been rather cautious on this in his papers (unlike his grouping of owl in falconiforms; other than vulturids in his phylogeny). Griffiths has presented three syringeal characters (taken from a select group of birds) that support a vulturid-falconiform clade (one of the characters is found in an owl however). The debate is still open.>>>


<<From what I know about avian phylogeny, the question is whether New World and Old World vultures are in fact related to one another in the first place. Some authors exclude the latter from all other falconiforms and do group them with the storks (there's a scavenging, vulture-like stork, the marabou).>>

I should have made this a little more clear. Griffiths (1994; also included is a refutation of S&A's DNA-DNA hybridization data, which is interesting) argues that vulturids (the New World vultures), if they are nested in Falconiformes, are the most basal members of the group because they lack certain syringeal characters found in falconids and accipitrids (including ospreys and secretary-birds, which do not differ greatly from classical accipitrids in syringeal anatomy) and that Old World vultures are nested with Acciptridae, which is really the old phylogeny. Griffiths evaluated the studies of Rea and Ligon that supported the vulturid-stork clade and found them to be based on plesiomorphic characters or ill-defined ones. I don't yet buy it, but I think that the whole vulturid-falconiform-stork thing is still an open question.

<<Then there's a suggestion that the maverick members of the Falconiformes and Strigiformes, hawks (?) and barn owls respectively, share some similarities, which might point to a divergence of Falconiformes from a Strigiformes + Caprimulgiformes clade.>>

This is mainly Joel Cracraft's tree, which has been reproduced dozens of times. However, Cracraft does not consider strigiforms to be nested close to caprimulgiforms (why? Because "caprimulgiforms are leading toward a swift design" (!)) and nests owls at the base of the falconiform tree a step above vulturids. *Nobody* accepts this.

Matt Troutman
m_troutman@hotmail.com


_______________________________________________________________ Get Free Email and Do More On The Web. Visit http://www.msn.com