The bones studied were unearthed in Shaanxi, China and date to 3,500 BC Scientists found ancient felines descended from the Asian leopard cat This suggests domestication in Asia occurred separately to that in Egypt However, the western cat replaced the leopard cat sometime after the end of the Neolithic age, possibly because of the opening of the Silk Road There are thought to be 500 million domestic cats worldwide, all descended from a form of wildcat native to north Africa