Posted by:
Upscale
at Fri Aug 17 00:21:41 2007 [ Report Abuse ] [ Email Message ] [ Show All Posts by Upscale ]
Dr. Bryan Grieg Fry is doing some research on the evolution of snakes by studying their toxins. He has been able to find cobratoxin and associated glands in snakes like ptyas, and to quote-“ We've subsequently found these toxins in pretty much every 'colubrid' species we've looked at,”. These snakes lack the evolutionary step to venom delivery typically associated with venomous snakes, but have the gland and venom. We all have heard that “modified salivary gland” description used for venom glands. Turns out a few colubrids have them too. Through his study of snake evolution by examining the venom in these snakes, we will probably see that some are more closely related to elapids. (I always thought those cribos looked a lot like some hots!) Almost all snakes are descended from snakes with venom glands, (perhaps sea snakes?) the effective delivery mechanisms in some are a notable advancement. Not sure if this is on the track of your post, but basically, a lot of snakes probably have toxic saliva and very poor delivery mechanisms. A venomoid that is a duct or partial gland removal, or where the gland may be regenerating (impossible with complete removal, of course) is just like any of these other snakes that posses the toxin, but ineffective delivery mechanism. A complete gland removal probably makes a venomoid less toxic than a lot of colubrids!
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