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Various evolutionary forces may shape the evolution of traits that influence the mating decisions of males and females. Phenotypic traits that males and females use to judge the species identify of potential mates should evolve in a punctuated fashion, changing significantly at the time of speciation but changing little between speciation events. In contrast, traits experiencing sexual selection or sexually antagonistic interactions are generally expected to change continuously over time because of the directional selection pressures imposed on one sex by the actions of the other. To test these hypotheses, we used spherical harmonic representations of the shapes of male mating structures in reconstructions of the evolutionary tempo of these structures across the history of the Enallagma damselfly clade. Our analyses show that the evolution of these structures is completely consistent with a punctuated model of evolutionary change and a constant evolutionary rate throughout the clade's history. In addition, no interpopulation variation in shape was detected across the range of one species. These results indicate that male mating structures in this genus are used primarily for identifying the species of potential mates and experience little or no selection from intraspecific sexual selection or sexual antagonism. The implications of these results for speciation are discussed.

In treating patients with infectious diseases, key knowledge and experience are essential in making appropriate clinical decisions. Medical students in Japan receive limited tuition in clinical pharmacology and microbiology in their undergraduate curriculum. Education and guidance in these fields are not always provided, even during postgraduate training. To help overcome this problem, we have devised a quick medical reference system to support antimicrobial chemotherapy, and this has been operating in our hospital since May 1994. This system is integrated in order to convey the maximal significance of test results by providing detailed information on various kinds of pathogens and antibiotics immediately on every computer display. This is a unique system in Japan, and aims to help doctors provide effective therapy. Using this system, we have succeeded in reducing medical expenditure for antimicrobials by around 10%.

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