Can you help me with the source of this quotation: "ontogeny recapitulates phylogeny?"
Ontogeny and phylogeny
It was Ernst Haeckel (1834–1919), German biologist and philosopher.
The phrase will probably live forever, because it neatly summarizes just about everything that the average high school graduate (including this writer) knows about human embryology and evolution; namely, that at some stage in its development the human embryo has both a clearly defined tail, indicative of our descent from the apes, and something resembling gills, indicative of our earlier descent from the fishes. Whether there is any truth in Haeckel's dictum beyond this rather broad relationship between individual development and species evolution, seems open to question.
But what do more knowledgeable people have to say?