Posted by:
mequinn
at Tue Sep 28 13:17:42 2004 [ Report Abuse ] [ Email Message ] [ Show All Posts by mequinn ]
Hi, No ignorence at all in your question, and as for long winded, I know the type! ....
Yes, there are differences in hemipenal morphology and even morphometrics among closely related species; take the V. prasinus complex: V. macraei has larger structurally very different hemipenes from either V. prasinus or V. beccari; V. beccari hemipenes are smaller than either V. prasinus or V. macraei and are very similar to shape to V. prasinus, hence the viable offspring Mike Stafani got when he crossed green x black morphs. But simply because a species can breed across species' lines does not mean it is 'closely' related to it - only hemipene structures and female acceptance allow it to happen - if fertile offspring are borne, then maybe this hemipene idea needs to be re-evaluated as I said post above it is the Order of the Day, and one I do not entirely accept at entirely correct, based only on 1 feature of morphology.
Like the V. gouldii complex, they are clearly related to one another, but their hemipene morphologies are abit different when you look at V. rosenbergi and V. gouldii forms; as for V. flavirufus and V. rubidus, I believe these to be merely eco-morphs of V. gouldii, and just junior synonym names for V. gouldii. The V. panoptes issue is more complicated as distribution is conflicting somewhat...and that subject is still under review by the Australians, chiefly by Graham Thompson, a damn nice guy who knows his goannas.
Did I answer your question? Im not sure....?? The v. albigularis complex was initially based on snout-shape and grouped with V. exanthematicus in 1905. Mertens established this in 1942, 1963. In 1981 Bill Branch noted differences in hemipenes among the 'Platynotan' varanus - between V. exanthematicus and V. albigularis group - hence they were split, and assigned their own complex. I conclude the albigularis group is a single complex as there is no (= -0-, zero) geographical separation between the complex anywhere across Africa (Bayless, 2002), or in climate (Bayless, 1997), (but may be for V. yemenensis) and is a single species, with V. yemeneensis as its closest out group; I believe V. yemenensis is the relict group and common V. albigularis is its outgroup or sister species. I try to stick with the Scientific Methodology to the letter, and it is a very sound formula for finding facts....and also a great deal of fun!
Cheers, mbayless
[ Reply To This Message ] [ Subscribe to this Thread ] [ Show Entire Thread ]
|