下面小编跟大家一起了解考研英语长难句系列分享，希望对大家的学习有所帮助、
　　The grand mediocrity of today -- everyone being the same in survival and number of offspring -- means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes.
　　译文：今天这种每个人的生存机会和子女数量都相同的极其显著的平均化，意味着与部落相比，自然选择在印度社会中、上层中已经失去了80%的效力。
　　难句类型：结构复杂
　　解释：句子的主干是The grand mediocrity of today means that…（主句） the natural selection…（宾语从句），破折号之间是伴随状语；主句和从句中都没有进一步的从句，因此整句话相对来说不难理解。
　　意群训练：The grand mediocrity of today -- everyone being the same in survival and number of offspring -- means that natural selection has lost 80% of its power in upper-middle-class India compared to the tribes.