In the eye of the cyclops: The classic case of cospeciation and why paradigms are important

Authors: BROOKS, DANIEL - University Of Nebraska; Hoberg, Eric; BOEGER, WALTER - Universidade Federal Do Parana

Submitted to: Comparative Parasitology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/20/2015
Publication Date: 1/31/2015
Publication URL: http://dx.doi.org/10.1654/4724C.1
Citation: Brooks, D.R., Hoberg, E.P., Boeger, W.A. 2015. In the eye of the cyclops: The classic case of cospeciation and why paradigms are important. Comparative Parasitology. 81(1):1-8.

Interpretive Summary: Most parasitologists and many in the broader zoological community have accepted or promoted the idea that host-parasite associations and their development are strongly linked to coevolution and cospeciation. A generality for association by descent emerged from the initial development of concepts about evolution and the seemingly tight connections demonstrated among hosts and parasites, although exceptions or departures from this orthodoxy have long been noted for insect-plant systems and even among parasites in vertebrates. Adherence to a core paradigm of maximum co-speciation has continued even in the face of considerable empirical evidence to the contrary. We examine the classical model that has been presented for cospeciation and demonstrate that relationships among lice and pocket gophers are explained in a more robust manner by alternating cycles of host switching (shifting to new hosts) and diversification. Further, we demonstrate that the conceptual frameworks used by different groups of researchers regarding the nature of cospeciation have been insufficient. Re-examining what has been dubbed the “classic case of co-speciation” shows that divergent views of co-speciation are subsumed and reconciled within a larger explanatory framework in which association are strongly influenced and determined by processes of host colonization. The implications for parasitologists, disease ecologists wildlife biologists and others in the zoological community are considerable, given the need to have a fundamental understanding of faunal structure, assembly, and distribution along with the historical and evolutionary drivers for diversity in an arena of accelerating environmental change, ecological perturbation and emerging infectious diseases.

Technical Abstract: Scientific disagreements due to empirical problems - not enough data, not enough of the critical type of data, problems in analyzing the data - are generally short-lived and resolved in the next cycle of data production. Those disagreements are thus transitory. Persistent scientific conflicts do not necessarily mean some facts are correct and some are wrong, or that we do not have enough of them. More often it means that the conceptual frameworks used by different groups of researchers are insufficient for resolving apparent conflicts in the data. This seems to be the case with persistent disagreements about the phenomenon of co-speciation. In particular, there has been no framework that allowed us to understand speciation by host switching in which host and parasite lineages were nonetheless of equal ages. That has now changed with the emergence of the Stockholm Paradigm. Re-examining what has been dubbed the “classic case of co-speciation” shows that divergent views of co-speciation are subsumed and reconciled within a larger explanatory framework called the Stockholm Paradigm. The implications are considerable, given the need to have a fundamental understanding of faunal structure, assembly, and distribution along with the historical and evolutionary drivers for diversity in an arena of accelerating environmental change, ecological perturbation and emerging infectious diseases.