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Monitor lizards ? commonly kept as pets ? and iguanas produce venom, according to surprising new research that is rewriting the story of lizard and snake evolution.

Until now, nasty swellings and excessive bleeding as a result of a lizard bite were blamed on infection from the bacteria in the creatures? mouths. Venom had been considered the preserve of advanced snakes and just two species of lizard ? the gila monster and the Mexican bearded lizard. And scientists had thought these lizards evolved venom production independent of snakes.

But research Bryan Fry?s team at the University of Melbourne, Australia, now suggests that venomous lizards are much more widespread than anyone realised. Furthermore venomous lizards and snakes are in fact descended from a common ancestor that lived about 200 million years ago.

In a related paper published in the journal CR Biologies this week, two of Fry?s co-authors, Nicolas Vidal and Blair Hedges of Pennsylvania State University, US, christen this new toxic taxonomic clade Toxicofera. They also suggest a complete overhaul of the conventional classification of lizards and snakes, based on new DNA analysis.

?These are very exciting papers,? says Harry Greene, a herpetologist at Cornell University, US. ?They threaten to radically change our concepts of lizard and snake evolution, and particularly of venom evolution.?

Source:
http://www.newscientist.com/article.ns?id=dn8331

Nice find, Dan. Thanks for posting it.

Am I interpreting this correctly - using cladistics (a form of taxonomy that uses genetics as a basis for classifying organisms according to their presumed evolutionary relationship) scientists have made a prediction that monitors and other lizards are much more closely related to snakes than previously supposed and that these things produce venom - which was THEN verified?

In short, is it honest to say evolution made a testable prediction which was borne out by the facts, or is that a stretch?

That sounds like an accurate perception from my reading of the article, FF. Observation led to hypothesis led to testing led to confirmation of hypothesis with other lizards. All science rests on acute observation.