Lewis Thomas book The Lives of a Cell: Notes of a Biology Watcher
"On Probability and Possibility"
The Lives of a Cell: Notes of a Biology Watcher (1974)
Context: Statistically the probability of any one of us being here is so small that you would think the mere fact of existence would keep us all in a contented dazzlement of surprise. We are alive against the stupendous odds of genetics, infinitely outnumbered by all the alternates who might, except for luck, be in our places.