Chromosome Database of Japanese Wild Mammals

Since 1970's, karyosystematics of Japanese mammals have been studies to elucidate the taxonomic and phylogenetic relationships. As a well-phrased remark, Dr. Hitoshi Kihara said in 1946 as follows: ''The history of the earth is recorded in the layers of its crust; the history of all organisms is inscribed in the chromosomes.'' As described in the remark, chromosome study is important for organic evolution at present. Different organisms have different karyotypes, and generally the karyotypes of closely related species are more similar to each other than to those of distantly related species. So, we are able to regard numerous and morphological changes in chromosomes as evident characteristics of the evolutionary process. Much DNA markers have been certainly useful to understand phylogenetic relationship and evolutionary history, but the DNA markers can reveal only 'genic phylogeny and evolution' and are unable to trace the total genome evolution, species evolution and speciation. Thus, studies of karyosystematics and chromosomal evolution are quite important and informative to study natural history of all mammals. This web site 'Chromosome Database of Japanese Wild Mammals' is dedicated to providing information on the chromosome evolution of the mammals in Japan and all cytogeneticists in natural history. The web pages are composed of numerous contributions by Drs. Kimiyuki TSUCHIYA, Takao ONO, Tatsuo OSHIDA and Shin-ichiro KAWADA. Many visitors to this site enjoy reading in depth about scientific works with the cytogenetics in the Japanese wild mammals !!