Chapter 8 Sociobiology I.Teaching Objective: 1.let the students know the importance of Sociobiology 2.Help the students to master biological basis of social behaviour L.Focal Points and Difficulties in the Chapter(教学重点和难点) 1.Focus The volution of altruism in explained by kin selectionr.Kir selection oceurs when the decrease in an individual's fitness as a result of its altruism is more than compensated for by the inereased fitness of its relatives. 2.Difficulties Reciprocal altruism occurs when an individual pays back a previous act of altruism. Groupse is probably unimportantitheiofnimal behaviour. Methodology Powerpoint presentation will be the main method.Blackboard will be an assistance.Fifteen minutes'discussion will be arranged.Some beautiful diagrams have been prepared for visualization. IV Presentation(课堂讲解，学时分配为2学时左右) Step 1.Warm-up Activity List the main ecological problems both in China and all over the world Let the students have a understanding about importance of discipline of ecology in the chapter. Step 2.The students are required to finish reading the whole text before the class and try to understand the major points of the chapter.The students are supposed to underline the difficult words or structures and raise their questions concerning