Beintema J J
J Mol Evol. 1977 Aug 5;9(4):363-6. doi: 10.1007/BF01796099.
Investigation of 17 insulin sequences from a bony fish, a bird, and 5 mammalian species showed that guinea pig and coypu insulin, that have a strongly divergent primary and quarternary structure, are not the result of gene duplication in an ancient vertebrate or invertebrate ancestor but they they diverged from the other mammals after divergence of the mammals from the other vertebrates. After this divergence both insulins underwent evolution at a highly increased rate.
对一条硬骨鱼、一只鸟和5种哺乳动物的17种胰岛素序列进行研究后发现，豚鼠和河狸鼠的胰岛素在一级结构和四级结构上差异很大，它们并非古代脊椎动物或无脊椎动物祖先基因复制的结果，而是在哺乳动物与其他脊椎动物分化之后，从其他哺乳动物中分化出来的。在这次分化之后，这两种胰岛素都以极高的速率进行进化。
