考研英语是一门需要长时间积累的学科，对于备战2015考研的学子们来说，在此阶段，同学们应该主攻单词和语法，坚持每天1-2篇的英语阅读以此来培养语感。

　　The role of natural selection in evolution was formulated only a little more than a hundred years ago，and the selective role of the environment in shaping and maintaining the behavior of the individual is only beginning to be recognized and studied.

　　词汇突破：
　　in evolution 在演化中
　　formulated 阐述;表述;解释;论证
　　shaping 形成(造就)
　　maintaining 保持，维护
　　recognized 认可，承认

　　主干识别：这里是两个并列句：
　　1. The role of natural selection was formulated.
　　2. The selective role of the environment is only beginning to be recognized and studied.

　　其他成分：only a little more than a hundred years ago 状语
　　in shaping and maintaining the behavior of the individual 状语

　　参考译文：自然选择在进化中的作用仅在一百多年前才得以阐明，而环境在塑造和保持个体行为时的选择作用则刚刚开始被认识和研究。

　　特别提示：被动语态的处理是翻译中的一个重要的知识点，多关注。