中文摘要：西奥多·德莱塞将社会达尔文主义成功地运用到了《嘉莉妹妹》中，通过人物的描写真实地反映了19世纪末20世纪初的美国社会。《嘉莉妹妹》这本书中可以明显地看出社会达尔文主义思想。本文一共分为五个章节。第一章的内容为文献综述、研究意义以及社会达尔文主义的介绍。第二章介绍自然选择在书中的体现。在自然选择的过程中，环境因素和个人因素会影响自然选择的结果。第三章介绍社会达尔文主义中适者生存的观点。在赫斯特伍德和嘉莉身上都体现了适者生存的观点。强者比弱者更容易生存，但不意味着弱者会灭亡。弱者和强者是相对的，弱者可以通过努力变成强者。第四章介绍道德进化，分析嘉莉为了生存所做出的行为，说明人类道德进化的过程中会受到外界因素的影响，但总体往好的方向发展。最后一章，简要总结前面的内容。本文通过分析社会达尔文主义在书中的体现,从而探讨嘉莉如何在大城市生存。

关键词：西奥多·德莱塞；《嘉莉妹妹》；社会达尔文主义；生存；适应

Abstract

Theodore Dreiser successfully applies social Darwinism to Sister Carrie, which truly reflects the reality of American society in the end of the 19th century and the beginning of the 20th century. Social Darwinism can be seen obviously in Sister Carrie. This paper is divided into five chapters. The content of the first chapter includes literature review, research significance and the introduction of social Darwinism. The second chapter introduces the embodiment of natural selection in the book. In the process of natural selection, environmental factors and personal factors will affect the results of natural selection. The third chapter introduces survival of the fittest in social Darwinism. Both Hurstwood and Carrie embody the idea of survival of the fittest. It is easier for the strong to survive than the weak, but it does not mean that the weak will perish. The weak and the strong are relative. The weak can become the strong through efforts. The fourth chapter introduces the evolution of morality, analyzes Carrie's behavior in order to survive, and shows that the process of human moral evolution will be affected by external factors, but it will develop in a good direction. The last chapter is a brief summary of the previous content. By analyzing the embodiment of social Darwinism in the book, this paper discusses how Carrie survives in the big city.

Key words: Theodore Dreiser; Sister Carrie; social Darwinism; survival; adaptation