After the Beagle voyage, Darwin filled notebooks with his ideas, and in 1837 sketched a genealogical pedigree, his earliest thoughts on the origin of species.

• 在贝格尔号航行之后，达尔文用他的想法填补笔记簿里的空白，并在1837年绘制了系谱略图，那是他关于物种起源的最初思考。