Lovelock first sketched out his theory in his bestseller, <em>Gaia: A New Look at Life on Earth</em>. People all over the world embraced the theory, and in less than ten years it moved from the margins of scientific research to the mainstream.<br /><br />Lovelock argues that such things as the level of oxygen, the formation of clouds, and the saltiness of the oceans may all be controlled by biological processes. He believes that "living organisms create the optimum conditions for their own existence, and in so doing create the superorganism Gaia." <em>The New York Times Book Review</em> has called his arguments in favor of Gaia "plausible and above all illuminating."