The wolf is the best domesticated animal among all animals raised by humans - all dogs originated from wolves. Savolainen et al. analyzed the maternal inheritance mitochondrial DNA of 654 dogs from Asia, Europe, Africa, and the Arctic Americas. They found that all dogs could be divided into five groups, with 95% of dogs belonging to three major groups that could be traced back to specific female wolves. Tracing further back, it leads to a wolf that lived 40,000 years ago. Genetic diversity in East Asia, such as China, Thailand, Cambodia, Tibet, South Korea, and Japan, is higher than in Europe, West Africa, and the Arctic North America, indicating that dogs in East Asia are the oldest population. Previously, researchers believed that the Middle East was the center for the domestication of plants and animals. Savolainen stated that most earlier guesses focused on the Middle East but were based only on a few archaeological findings, which also indicated the domestication of other animals there.