 Machery and Barrett (2007) argue that Buller has no clear critical target as there is nothing to the idea that there is a research tradition of evolutionary psychology that is distinct from the broader enterprise of the evolutionary understanding of human behavior. They argue that theoretical tenets and methods are shared by many in the biology of human behavior. For example, many are adaptationists. But as we saw above, evolutionary psychologists and behavioral ecologists can both call themselves adaptationist but their particular approach to adaptationism dictates the range of hypotheses that they can generate, the range of traits that can be counted as adaptations and impacts upon the way in which hypotheses are tested. Research traditions can share some broad theoretical commitments and yet still be distinct research traditions. Secondly, they argue against Buller’s view that past environments are not stable enough to produce the kind of psychological adaptations that evolutionary psychologists propose. They take this to be a claim that no adaptations can arise from an evolutionary arms race situation, for example, between predators and prey. But again, I think that the disagreement here is over what counts as an adaptation. Buller does not deny that adaptations— traits that arise as a product of natural selection—arise from all kinds of unstable environments. What he denies is that organ-like, special purpose adaptations are the likely result of such evolutionary scenarios. 