请你把中文翻译成为英文
这个发现的解释是渡鸦在加利福尼亚州已住上了最少二百万年，并在冰河时期与牠在欧洲及亚洲的亲属分开。
One explanation for these genetic findings is that common ravens settled in California at least two million years ago and became separated from their relatives in Europe and Asia during an ice age.