The theory of punctuated equilibrium, proposed by Niles Eldredge and myself, is not, as so often misunderstood, a radical claim for truly sudden chan… - Stephen Jay Gould

Evolving life must experience a vast range of possibilities, based on environmental histories so unpredictable that no realized route - the pathway to consciousness in the form of Homo sapiens or Little Green Men, for example - can be construed as a highway to heaven, but must be viewed as a tortuous track rutted with uncountable obstacles and festooned with innumerable alternative branches. Any reasonably precise repetition of our earthly route on another planet therefore becomes wildly improbable even in a trillion cases.

Flies can eat toads! (Although astonishment may be lessened in noting that the tiny toads are much smaller than enormous fly larvae.) Unusually large insects and maximally small vertebrates have also been featured in the few other recorded cases of such reversals - frogs, small birds, even a mouse, consumed by praying mantids, for example.

When we seek a textbook case for the proper operation of science, the correction of certain error offers far more promise than the establishment of probable truth. Confirmed hunches, of course, are more upbeat than discredited hypotheses. Since the worst traditions of “popular” writing falsely equate instruction with sweetness and light, our promotional literature abounds with insipid tales in the heroic mode, although tough stories of disappointment and loss give deeper insight into a methodology that the celebrated philosopher Karl Popper once labeled as “conjecture and refutation.”