	Businesses Classifieds Forums Photos Chat News Video Podcast Features Events Clubs Bookstore

Reptile & Amphibians Insects Birds Cats Dogs Exotics Horses Aquaria Ponds PetHobbyist PetPress PetSupport RescueNetwork My Account
facebook - twitter - jeffb's facebook	racing - field outfitter - reptile laws - kingsnake shirts - club.kingsnake - advertising rates - site news - help - contact

Looking for a pet? Try a rescue first!

Medium Rats $.99, XL Rats $.99, XXL Rats $.99 at RODENTPRO.COM
Reptile & Amphibian Chat Sunday 9-11 PM Eastern - Click here!

Re: Snake Origins

[ Follow Ups ] [ Post Followup ] [ The Taxonomy Forum ] [ FAQ ]

Posted by Troy H. on March 08, 1999 at 21:42:43:

In Reply to: Snake Origins posted by SNYDER on March 08, 1999 at 18:21:26:

the way i understand it (and its been about 4 years since my grad school days, so pardon if i mess up a few details) is that snakes and amphisbaenians are clades within the lizard clade that includes geckos, skinks, anguids, teiids, and of course monitors. The other lizard clade includes all of the iguania (agamas, chameleons, and all the divers species of "iguanids" (in the sense used prior to Hillis and Frost).

however, unless i've missed something since i left academia, no one has yet shown that snakes are not monophyletic -- that is, there is no extant lizard species or group nested within the snake clade, even at its most basal position. So while snakes may have evolved more than once, they very likely did so from very closely related lizard groups. What is more likely, however, is that snakes in fact did evolve once, and that the anatomical differences you point out (left or right lung vestigial) result from the fact that the original snake had both lungs (this original is prior to the splits between blindsnakes and other snakes) . . . however, this original snake taxa later evolved to lose the lung, and different subsequent groups lost different lungs (hope that all makes sense ;-) )

Troy

Follow Ups:

Monophyletic/Paraphyletic SNYDER 3/13/99 (2)
- Re: Monophyletic/Paraphyletic Troy 3/24/99 (0)
- Re: Monophyletic/Paraphyletic Jerry Feldner 3/15/99 (0)

Post a Followup

Name:
E-Mail:

Subject:

Comments:
: the way i understand it (and its been about 4 years since my grad school days, so pardon if i mess up a few details) is that snakes and amphisbaenians are clades within the lizard clade that includes geckos, skinks, anguids, teiids, and of course monitors. The other lizard clade includes all of the iguania (agamas, chameleons, and all the divers species of "iguanids" (in the sense used prior to Hillis and Frost). : however, unless i've missed something since i left academia, no one has yet shown that snakes are not monophyletic -- that is, there is no extant lizard species or group nested within the snake clade, even at its most basal position. So while snakes may have evolved more than once, they very likely did so from very closely related lizard groups. What is more likely, however, is that snakes in fact did evolve once, and that the anatomical differences you point out (left or right lung vestigial) result from the fact that the original snake had both lungs (this original is prior to the splits between blindsnakes and other snakes) . . . however, this original snake taxa later evolved to lose the lung, and different subsequent groups lost different lungs (hope that all makes sense ;-) ) : Troy

Optional Link URL:
Link Title:
Optional Image URL:

[ Follow Ups ] [ Post Followup ] [ The Taxonomy Forum ] [ FAQ ]

also... Lizardkeepers.com | AprilFirstBioEngineering.com