The paper "The Clock: the Mammalian Suprachiasmatic Nucleus" is a delightful example of an article on biology. The article in review "The Clock the mammalian suprachiasmatic nucleus describes the pacemaker role of the suprachiasmatic nucleus in the mammalian circadian system thus the title correctly points out to the subject of the paper. The purpose of this experiment was to understand the biological clock found in most mammals. This clock is found in the SCN which is the suprachiasmatic nucleus in the hypothalamus part of the brain. The work is based on experiments done on hamsters whose T mutation provided the chance to test the role of the SCN as a pacemaker.
There were several reasons to undergo this experiment such as various pieces of evidence that led to this view. For example what the SCN is the target of and what it is required for, the fact that tissue explants that consist of the SCN keep on expressing circadian rhythms in electrical activity (Sanger et al, 5463) This work is important because it is this activity that regulates the body processes such as body temperature, hormone system, and their production as well as its effect on drug abuse and sexual orientation in humans.
With this study, the scientists used transplants of the SCN in animals whose own nucleus was absent. The results showed that the rhythms matched the period of the donor and not the genotype of the host. So it was proven that the circadian rhythm is determined by the SCN regardless of where the cells came from meaning that the clock does exist in mammals.