Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Venemous Snake Evolution
Name: Kim R.
Status: educator
Age: 40s
Location: N/A
Country: N/A
Date: Tuesday, May 07, 2002


Question:
I have been asked by a student, "How did the venomous snakes evolve? Why did some snakes become venomous and other not for instance, a garter snake and a rattler." I do know that some are constrictors and did not have the need for a toxic venom, but that does not account for the differences between vipers and a non-poisonous snake.


Replies:
I hope you get a more specific reply from someone who knows more about snakes than I do, but my stock reply to questions of "why" things happen in nature is, "because it works." Evolution is a somewhat random process of mutation and adaptation, and if something happens that works it will then be selected for and enhanced. If a mutation improves survival chances then it will be selected for in future generations, if not, it will disappear.

J. Elliott


Venomous snakes are predators seeking fast moving prey, usually mammals. They have evolved because their niche includes chasing their food. Snakes can not move very fast so the ambush and strike will allow the snake to eventually catch up to the previously faster moving but now dead prey. These snakes use their tongues to sense the heat trail produced by the warm blooded mammal. Garter snakes and the like have it easier in that their prey are slow to move in the first place, such as insects, etc. It would be a waste to be posionous when you don't need it. Evolution has fine tuned all existing organisms, so snakes are the way they are because it works. Natural selection is a powerful force, but effective in developing the best species.

Steve Sample


Click here to return to the Zoology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory