Posted by:
Wulf
at Mon Feb 13 06:32:48 2006 [ Report Abuse ] [ Email Message ] [ Show All Posts by Wulf ]
Hi John,
I've had a go at working out why there's so much character conflict in Kluge's (1993) morphological data set, particularly involving Liasis (in the broad sense). As a breeder you're no doubt aware of various reported cases of healthy hybrids of python species belonging to separate species groups or genera. I'm not sure whether any of these progeny have turned out to be fertile, but it does raise the question whether any species or group of living pythons arose by hybridization of previously separated lineages.
Good point, John. I have produced offsprings of Morelia nauta x Morelia spilota cheynei just by keeping them in the same cage. They were readily breeding and producing quite good looking and healthy offsprings. They are closer to the carpets in general appearance, but have the typical head scalation of the (former M. amethistina) Morelia nauta. We'll see if they are fertile in a couple of years...
Well, it would certainly be difficult to prove (or disprove)from morphological evidence alone, but after playing around with the morph data and drawing a lot of reticulating diagrams (relaxing just one of the usual cladistic assumptions), I still think it likely there was at least one hybrid origin of a species, and may have been others further back.
Well, I recall Kluge (1993) had placed A. papuanus between M. boeleni and some Liasis species and in a strict consensus diagramm (Fig. 27) he even placed the spilota group as well as viridis as a branch of the papuanus and olivaceus as another branch of papuanus. This would come close to what you assumed, anyway. This is perhaps the same in M. oenpelliensis I think.
The one I think most likely is an introgression between olivacea-like and amethistina-like ancestors to produce papuana. That is to say, 'Apodora' papuana (with a *o*) is a Liasis-Morelia hybrid that originated after both Liasis and Morelia had diversified. Maybe boeleni is more closely related to papuana than to anything else, but papuana is equally closely related to olivacea.
I think McDowell (1975) (or was it Brongersma 1953, 1956) assumed that M. boeleni could be closely related to Leiopython albertisii.
This is unknown but testable. If I'm right, separate gene-trees will support different cladograms, and with enough nuclear DNA we'll get the full story.
There is still a lot of research to be done in basal snakes until we know the true story. At the end it perhaps turns out right what Underwood & Stimpson (1990) suggested... there is only Morelinii (austral-asian species) and Pythoninii (african species)...
Cheers,
Wulf
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