The concept of punctuated equilibrium was, to some, a radical new idea when it was first proposed by Stephen Jay Gould and Niles Eldredge in 1972. Now it is widely recognized as a useful model for ...

Gould's hopeful monsters were the homeotic mutants of Drosophila melanogaster, notorious for their transformed body parts—wing to haltere, antenna to leg. Although the essay lacks the trademark ...