Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
C H A P T E R 13 Interspecific Interactions Because organisms depend on each other for food and other biotic factors, they inevitably interact with each other. Although the most intense relationships exist between members of the same species. | I Text Linzey Vertebrate Biology The McGraw-Hill Companies 2003 13. Interspecific Interactions CHAPTER 13 Interspecific Interactions INTRODUCTION Because organisms depend on each other for food and other biotic factors they inevitably interact with each other. Although the most intense relationships exist between members of the same species individuals do not live apart from members of other species. Living in close association different species may compete for a shared resource such as food space or moisture. These interactions can be classified into several categories competition symbiosis commensalism mutualism parasitism predation and human interactions. In competition both species are affected adversely in commensalism one species benefits and the other is unaffected in mutualism species benefit each other in parasitism and predation one species benefits and the other is harmed. Human interactions may benefit both species only one species or possibly either species. COMPETITION The concept of interspecific competition is one of the cornerstones of evolutionary ecology. Darwin based his idea of natural selection on competition the struggle to survive. Whenever different species occupy the same place at the same time there will likely be competition for common resources such as food water or space that are in limited supply. Such interspecific competition consumes both time and energy. Stress caused by such competition may decrease growth and birth rates and or increase the death rate if intense competition can slow or even halt population growth and cause the population to decline. If ecological requirements of two species are similar but not identical selection pressure will tend to cause the species to diverge from each other through morphological physiological and or behavioral specializations. However if two species have identical ecological requirements they will not be able to coexist because of competition for limited resources. Competition is difficult
