Most biological systems are complex adaptive systems and handle changes quite well. Killing off a few species of mosquitoes or parasites that only live in human

Most biological systems are complex adaptive systems and handle changes quite well. Killing off a few species of mosquitoes or parasites that only live in humans, is unlikely to upset any ecosystem in a major way. Plowing up all of the native grass land in the American Mid-West to grow corn or cutting down the Amazon rain forest to grow soybeans; these are the large scale wholesale destruction of the environment that people should be concerned about.