دانلود کتاب عدم تقارن جانبی در حیوانات – تعاملات شکارچی و شکار، پویایی و تکامل

This book reviews recent studies, mainly of ours, on the laterality of fish and other animals. The studies started from a discovery of asymmetric mouth opening of scale-eating cichlids in an African lake, and extended to lateral dimorphism and corresponding behaviors of all the fishes, and now eventually stretches to some aquatic invertebrates. During the studies, we often received queries, such as “Why the fish developed such a character?” and “Could they act more efficiently when they have a symmetric body and unbiased behaviors?” We always answered such as “We don’t know the exact reason at present, but we can only say that they seemed to develop and retain the character as it has been more useful for their life. Incidentally, we suppose that you too have a clear handedness, as either righty or lefty, haven’t you?” The remarkable nature of laterality is such that most people make little account of it, despite the facts that everyone are bound by and also that this dimorphism has been maintained with a certain ratio in every population in every era. Historically, the laterality had been studied mainly on the handedness of human being, as its unique property, and had been related to the cerebral lateralization. A large number of papers, books, and even an international journal specific to the lateral asymmetry had been published. After that, studies on animals have been started on mammals, especially on non-human primates and experimental animals (the rat and mouse), and then spread over companion and/or domestic animals, birds, and then fishes in aquariums. In these studies, however, the laterality has been studied mainly from the viewpoint of the behavioral asymmetry in relation to the brain lateralization, but the morphological asymmetry was rather disregarded except the asymmetry in central nerve structure. These studies have issued mainly from a viewpoint of a characteristic of species, or a property of individual. Whereas, this book, focusing on fish and aquatic invertebrates, addresses the relation of morphological asymmetry to the behavioral laterality clarified mainly by our recent studies. Our studies put emphasis on interspecific interaction, especially predator–prey interaction in community, and pay attention to frequency-dependent selection. We will discuss also the phylogenetic relation of the laterality of fish, as well as its origin and inheritance, to the tetrapod animals, and the relation to that of invertebrates. Although an extensive adjustment of our works to the result of conventional studies remains as a subject in future, we hope that readers can enjoy a new field of the laterality of animals.  “The ratio of scale-eater’s laterality seems to oscillate, but the difference from 0.5 is not significant.” My study on lateral asymmetry was elicited by these words. I (S.T.) first met Prof. Hori at the seminar of Animal Sociology Lab. in Osaka City University, where he talked about scale-eater’s lateral asymmetry. At that time, I got my first job position at the Department of Mathematics in O. C. U. and was studying fractals. Hori’s data of scale-eaters laterality ratio between 1980 and 1990 seemed to oscillate with 5-year period, but the difference from 1:1 ratio is not significant for each year. To show the oscillation, I approached from two directions, statistics and modelling. Though I was not familiar with many statistical methods, I could calculate probabilities. I accumulated laterality ratio data of different years by Fourier transform and showed its significance. This statistical approach is summarized in Chap. 7 of this book. Another approach to prove the oscillation was modelling oscillation mechanism. Incorporating minority advantage of lateral dimorphism in predation and time delay of 2-year growth period into the model of scale-eater replicated its 5-year periodic oscillation of laterality ratio. This population dynamics modelling approach is summarized in Chap. 5. I enjoyed collaboration with Prof. Hori, observing scale-eater’s attack on a goldfish in his laboratory tanks, etc.