According to Karl Popper, a theory is scientific if, and only if, it could be shown false by observations. Richard Lewontin and Stephen Jay Gould criticize adaptationism in evolutionary biology when they write,
"We would not object so strenuously to the adaptationist program if its invocation, in any particular case, could lead in principle to its rejection for want of evidence." (Sober 2006, 86)
Given their critique of adaptationism, is evolutionary theory scientific in Popper's sense?