Animal genetic resources for food and agriculture crop and livestock species in the early neolithic time period changed our human evolution and lifestyles. This ability to control food production led to major demographic, technological, political and military changes. Consecutively, thousands of years of natural and human selection, genetic drift, inbreeding, and crossbreeding have contributed to the diversification of animal genetic resources and increased the variety of environments and production systems that livestock keeping takes place. Relatively few species have been domesticated; out of the world's 148 non-carnivorous species weighing more than 45 kg, only 15 have been successfully domesticated. The proportion of domesticated birds used for food
Endangered Species Act of 1969 passed prior to the 1969 act, and set up a list of species native to the United States that qualified as endangered. The animals on this list were then afforded certain protections from the National Wildlife Refuge System. For example, the Endangered Species Preservation Act was in part dedicated to raising awareness of endangered species of birds like the peregrine falcon, and to "conserve, protect, restore, and propagate certain species of native fish and wildlife". Despite these protections, however, researchers found that the act was insufficient. This led to the passage of the Endangered Species Conservation Act of 1969. The