There is some uncertainty about what exactly the Bible means when it talks of "kinds." Creationist Brian Nelson claimed "While the Bible allows that new varieties may have arisen since the creative days, it denies that any new species have arisen." However, Russell Mixter, another creationist writer, said that "One should not insist that "kind" means species. The word "kind" as used in the Bible may apply to any animal which may be distinguished in any way from another, or it may be applied to a large group of species distinguishable from another group ... there is plenty of room for differences of opinion on what are the kinds of Genesis."