Ellis, in Walker's view, scientific evidence demonstrated that environmental and anthropomorphic damage was caused by overpopulation, calling Ellis' view "nonsense." Although the Earth has limited resources, Ellis argues that “there is no carrying capacity.” All living things on earth will suffer because they will die due to the erosion of natural resources, mainly food and water. Modern humans, however, are an exception, as they are innovative. Although Ellis's thesis states that "humans have altered natural environments in ways that increase the carrying capacity of our species," Walker states that "past performance does not guarantee future results." Walker concludes by answering the question posed by Ellis by saying this; fighting overpopulation is: “not just silly, it's dangerous