I looked up that article and read it. Nowhere did they "encourage an increase in population growth." In fact they note that their study "highlights the critical importance of current policies and actions for the long-range future of the world population." You start here: "By what law is (abortion) forbidden? Not natural law, that's for sure." You continue here: "this type of honor system has existed in a natural environment long before humans appeared and especially in different mammalian species. They don't know this but the thought or desire to infringe on another's rights, against which the other has a right to defend themselves, just does not occur." However, it does occur. The idea that animals do not "infringe on another's rights" because of "natural law" or an "honor system" is laughable; a Disney view of reality. Most animals are prey.