Careful sequence comparisons have shown that one cow gene for a ribonuclease enzyme was a pseudogene for much of its history but appears to have been reactivated during recent evolutionary time.

• 在仔细比对序列之后，科学家发现牛的某个核糖核酸酶基因，在漫长的演化中一直是个伪基因，直到最近才重新活化。科学家还发现，个体间的伪基因有些微的差异。