Progress in the coadaptation and coevolution between plants and herbivores
植物与草食动物之间的协同适应及进化

Many evolutionary biologists, ecologists, and geneticists etc. are focusing on the biological phenomenon derived from evolutionary relationships and past interactions-the coadaptation and coevolution between plants and herbivores in the natural world. It was assumed that this phenomenon or problem would be the study endpoint (crossing point) of many biological science branches such as evolution, ecology, and genetics etc. though unifying all branches under an evolutionary theme is still difficult. The purpose of this paper is to bring together some prevailing knowledge and ideas about the coadaptation and coevolution between plants and herbivores, and also comment on the theoretical meaning and constraints of this field. Coevolution is defined as evolutionary changes in one or more species in response to changes in other species in the communities or ecosystems. The author explained that coevolution could be given a good understanding as the predator-prey relationships and organism-habitat (environment) relationships in a broader sense. In this field, the substantially observed or studied biological objects with coevolution relationships are classified into the five systems: insect pollination system, induced response system of plant by insect, seed dispersal system, and large herbivore foraging-plant response system. The central contents of the coadaptation and coevolution between plants and herbivores are to determine and compare phenotypic plasticity and elucidate the coadaptation and coevolution mechanisms. Phenotypic plasticity is described as morphological, physiological or ecological plasticity by evolutionary biologists. Development plasticity was also put forward. Variations in phenotypic plasticity could be explained from genetic differentiation of species. Recent decade has seen intense interests in the study of plant-herbivore coevolution mechanisms including the induced plant responses to herbivores such as most insects, the foraging behavior strategies of herbivores on heterogeneous habitats such as food and landscape, compensation or overcompensation growth of plants responding to herbivore foraging, and changes in the fitness and ecological costs (including investments of resistance, tolerance, growth and reproduction) of plants and animals. The foraging behavior framework includes foraging theories such as Rule of Thumb, Marginal Value Theorem, and Optimal Foraging Theory. The author discussed the key limitations to the study of coadaptation and coevolution between plants and herbivores such as the parameters describing effective fitness of plants and animals.