The genome starts piling on mutations that mean nothing; that's how they date the branches of the genome, by looking at the number of neutral mutations.

基因积累了许多无意义的突变,这就是他们如何鉴定基因分支的年代,看中性突变的数量就行了

耶鲁公开课 - 金融市场课程节选

I'd like to go by climbing a birch tree, And climb black branches up a snow-white trunk toward heaven, till the tree could bear no more, But dipped its top and set me down again.

我真想去爬白桦树，沿着雪白的树干，爬上乌黑的树枝，爬向那天心，直到树身再支撑不住，树梢碰着地，把我放下来。

耶鲁公开课 - 现代诗歌课程节选