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
The Clements Checklist of Birds of the World is the official list used by the American Birding Association for birds globally. eBird also uses the "Clements" checklist as the base list for its eBird taxonomy, which in addition to species includes hybrids and other non-species entities reported by birders. The Clements Checklist of Birds of the World The Clements Checklist of Birds of the World is a book by Jim Clements which presents a list of the bird species of the world. The most recent printed version is the sixth edition (2007), which was published by Cornell University Press. Previous editions were published by the author's own imprint,