More mosquitoes, hungry birds of prey, mass extinction of amphibians. It's possible, says Dr. Andrew Blaustein, an Oregon State University zoology Professor who is watching frog populations morph.  Some growing up to 14 extra legs because of a parasite propelled by pollution. He believes a sixth mass extinction event could be in the works, due to pollution.  The same parasite, the flat-worm, is dangerous for humans and other animals as well. Blaustein says the parasite appears to thrive in polluted waters.