This one from 2010, sent in by a reader. From John Horgan at Scientific American:
Early in his career, the philosopher Karl Popper ,, called evolution via natural selection “almost a tautology” and “not a testable scientific theory but a metaphysical research program.” Attacked for these criticisms, Popper took them back (in approx 1978). But when I interviewed him in 1992, he blurted out that he still found Darwin’s theory dissatisfying. “One ought to look for alternatives!” Popper exclaimed, banging his kitchen table.
Popper was forced to back down from public expression, of course, because one cannot doubt Darwin and still be Big Cool. Stupidity is much safer and more popular. But life goes on and so does doubt.
See also: Karl Popper never really retracted his skeptical view of Darwinism
Scientific American Science writer John Horgan still doubts cosmic inflation …