In closing his 1859 abstract, On the Origin of Species, Charles Darwin wrote one of the most poetic passages in the history of science. “There is grandeur in this view of life, with its several powers, having been originally breathed into a few forms or into one;” Darwin wrote, “and that, whilst this planet has gone cycling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved.” Beautiful. And in this cherished passage, there’s one phrase that always jumps out at me.

What did Darwin mean when he mentioned “endless forms”? Sometimes I wonder if Darwin meant to