科学家在分析了哥伦布到达美洲前的狗的脱氧核糖核酸之后发现,在欧亚大陆,是狼变成了最初的狗,随后,这些狗伴随着人类穿过白令海峡到达了美洲。从第一只狗的诞生到现在已有将近4万年的历史。下面,我们来看一看关于狗的有趣数字:!据估计,全世界目前有4亿只狗。!世界上狗的种类有 Scientists analyzed the DNA of Columbus’s dog before it reached the Americas and discovered that in Eurasia it was the wolf that became the first dog. Later, these dogs came to America with humans crossing the Bering Strait. From the birth of the first dog to the present, it has a history of nearly 40,000 years. Let’s take a look at interesting figures about dogs:! It is estimated that there are currently 400 million dogs in the world. There are dog species in the world