Why was "tantrum" trending last week?
recapitulation theory re·ca·pit·u·la·tion theory (rē'kə-pĭch'ə-lā'shən)
See biogenetic law.
postulation, by Ernst Haeckel in 1866, that ontogeny recapitulates phylogeny-i.e., the development of the animal embryo and young traces the evolutionary development of the species. The theory was influential and much-popularized earlier but has been of little significance in elucidating either evolution or embryonic growth.