hopeful monster

noun Biology.

a hypothetical individual organism that, by means of a fortuitous macromutation permitting an adaptive shift to a new mode of life, becomes the founder of a new type of organism and a vehicle of macroevolution.

Origin of hopeful monster

First recorded in 1933; phrase introduced by German geneticist Richard B. Goldschmidt (1879–1958)
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019