Insincere flattery? Understanding the evolution of imperfect deceptive mimicry

Mimicry is the phenotypic resemblance of one organism to another because the resemblance is favored by selection from a signal receiver who perceives the resemblance. We would expect mimics to resemble their models closely, yet the widespread existence of imperfect mimics confounds this expectation, and has led to a profusion of possible explanations for the phenomenon. Despite this, we still lack an understanding of what general evolutionary principles, if any, result in imperfect mimicry. A common approach to this problem is to test and compare several imperfect mimicry hypotheses with the aim of uncovering such general evolutionary principles. We suggest, however, that a better understanding of the hypotheses and clarification of the distinctions or similarities between them is necessary, since each hypothesis makes very different assumptions, requiring different analytical approaches. Therefore, this review aims to focus future studies into imperfect mimicry, and to aid in understanding how to test and compare hypotheses. First, we summarize and characterize hypotheses from the literature based on their types of explanation, subjects, and adaptive landscapes they predict for mimics. Next, we review evidence for the hypotheses, describe desirable characteristics of mimicry complexes for study, and finish by investigating mimicry complexes from past studies.