Several controversies still surround the time the chicken was domesticated. Recent molecular evidence obtained from a whole-genome study published in 2020 reveals that the chicken was domesticated 8,000 years ago. Though, it was previously thought to have been domesticated in Southern China in 6000 BC based on paleoclimatic assumptions which has now raised doubts from another study that question whether those birds were the ancestors of chickens today. The majority of the world's domestic chickens may be traced to the Harappan culture of the Indus Valley. Eventually, the chicken moved to the Tarim basin of central Asia. It reached Europe (Romania, Turkey, Greece, Ukraine) about 3000 BC.