Subduing prey and Making predators go away.
Your conslusion that if venom were for defense it would be more harmful is not quite on target. When venom is for defense, it needs to be more PAINFULL. Think ants, bees, wasps. It doesn't need to kill the predator or threat, just make it let go, run away or never attack again.
When it's for subduing prey or digestion, it needs to be DEADLY so that the prey doesn't injure the one injecting the venom, let the prey run away or at least not run too far. Think Black Widow Spiders or Rattlesnakes.
Venom in Heloderms is probably almost exclusively for defense. The stuff they eat, eggs, baby birds and rodents, etc, isn't likely to run away. It doesn't have much of a history of killing people (some say none), and we would certainly be a "predator" in the heloderms eyes. Those who have been bitten have made it clear... it hurts as bad as something can hurt.
I could come up with guesses why they evolved venom, but they would only be guesses. How about this: The prey they take doesn't run away fast, so any evolutionary pressure to develop fast moving legs would only be for escaping predators. The individuals developing a painful venomous bite expended less energy avoiding being eaten and thus were adapted better for times when food was scarce than were the lizards who had to expend energy running away from predators.
Just thoughts to mull over.
Doug T
>>But for digestion I believe. If it was for defense I would think the would have a better delivery system (hollowed fangs). Correct me if I am wrong but I believe they found the venoum to break down sugars and protiens very effecently, reasearch being done for diabetic control.(link)
>> Also if it was for defense it would be far more harmful and a anti-venoum would be required.
>>Just some facts with thoughts.
>>Robert
>>Monster Drug
