Research content

The earth, on which we live, rotates around the sun at a speed of about one revolution per year with its axis tilted. The earth's orbit causes cyclic changes in temperature and day length during the year in Japan, which is located in the mid-latitudes of the northern hemisphere, and gives rise to the seasons. On the other hand, in the tropics near the equator, where seasonal changes are small, ecosystems with extremely diverse organisms and huge biomass are widespread. We are conducting interdisciplinary research that combines seasonal biology and mathematical biology, aiming to clarify how organisms have adapted and evolved in response to these differences in the seasonal variation of the environment, and to predict the future.

Just as we each have differences in hair color, body shape, susceptibility to disease, etc., there is a wide range of individuality (intraspecific diversity) in almost every species on earth. Such diversity is created by differences in DNA sequences and environmental influences and is the source of biological evolution. On the other hand, the regulatory mechanisms of diversity, i.e., what kind of DNA sequence differences are translated and by what molecular mechanisms diversity is created, are largely unknown. To answer this question, we are using the model plant Arabidopsis thaliana and the natural population of the closely related species, Arabidopsis halleri, as models to study the differences in DNA sequences that produce differences in traits among individuals, their importance, and gene functions using various approaches such as genomics, quantitative genetics, and molecular genetics.

The “forms” of living organisms in nature are diverse, but not all forms can appear and exist. Our research aims to quantitatively understand the evolution of such diversity and conservatism in terms of both ultimate and proximate factors. Our research targets and scales are diverse, ranging from intracellular structures to communities of animals, plants, and artifacts. Furthermore, we apply theories and techniques for quantifying and modeling the “forms” created in the process to diverse fields such as agriculture, medicine, materials science, and archaeology, and are developing cross-disciplinary research.