Coevolution is a large part of evolution and the patterns of adaptation and speciation may be modified by coevolution processes. The arms races between insects and plants in natural system are one of coevolutionary processes and the mechanistic and predictive processes of the system may be helpful to understand the interaction between host plants and herbivores in agricultural systems. Furthermore, human activities may give direct and/or indirect effects on ecological and evolutionary processes in natural and agricultural ecosystems and have selection power as well as natural selection. Recent studies showed that the fundamental principles of evolution – variation (genetic difference, phenotypic plasticity, epigenetic change, and nongenetic inheritance), selection (directional or fluctuating), connectivity and eco-evolutionary dynamics – are important to understand the interplay between insects and plants. The coevolutionary processes between plants and herbivores were also interpreted by the geographic mosaic theory. The evolutionary effects on ecological dynamics in natural ecosystems were classified four categories: trophic specialization, evolution of defense, interaction outcome and loss of traits in absent of interaction. It was reviewed that it is necessary to consider the ecological response in evolutionary studies as well as evolutionary variation in ecological researches.

• Jeong Joon Ahn(Institute of agricultural science and technology, Andong National University)