Doubts about a unified cognitive theory of taxonomic knowledge and its memic status

The evidence for a panhuman, cognitively rooted, essence-based concept of basic natural kind and for certain prototypical phenomenal forms is increasingly compelling, but there remain doubts as to whether these two elements combine with a principle of taxonomy to form a unified, domain-specific theory in the way Atran claims. The appropriateness of the notion of meme can also be questioned, as can the assertion that humans are always grouped in ethnobiological classifications in unambiguous contrast to other animals.