来自《耶鲁大学开放课程：心理学导论 第10集 第10集》

• 
  
  but also from--the Gray textbook
  或者格雷的教材
• 
  
  and the Norton readings will both--will each provide you
  和诺顿文集 从中你们可以
• 
  
  with enough background to get up to speed.
  汲取到足够的背景知识
• 
  
  But the general idea is that there are three components to natural selection.
  总体来说 自然选择有三个组成部分
• 
  
  There is variation.
  物种之间的差别
• 
  
  And this variation gives rise to different degrees
  这个差别对生存和繁殖
• 
  
  of survival and reproduction
  产生不同影响
• 
  
  and gets passed on from generation to generation
  并一代代传下去
• 
  
  and gives rise to adaptations,
  进而影响对环境的适应
• 
  
  What Darwin described as
  达尔文把这描述为
• 
  
  "that perfection of structure that justly excites our imagination."
  恰好激发我们想象力的完美结构
• 
  
  And the biological world has all sorts of examples.
  生物世界里到处都是这种例子