This has been particularly useful for the phylogeny of microorganisms, to which the species concept does not apply and which are too morphologically simple to be classified based on phenotypic traits.

• 这对微生物的系统发生史特别有用，因为物种概念在微生物中并不适用，微生物的形态过于简单以致于不能依表型性状进行分类。