This is a
prestigious lectureship instituted in memory of Cam Stevenson, the long-time
Editor of the Canadian Journal of Fisheries and Aquatic Sciences (CJFAS), published by NRC
Press and is conferred upon a young, energetic and creative researcher
at the cutting edge of an aquatic discipline. Each year a Lecturer is selected
by the Journal's Editorial Board. In the Spring of
each year a call for nominations is sent to the Chairs of Zoology and Biology
Ecological speciation: Canadian fishes and the illusion of ubiquity.
Ecological speciation occurs when adaptation to different environments drives the evolution of reproductive isolation. This process is thought to have been very important in the evolution of biological diversity, and Canadian fishes have figured prominently in the theory’s development and widespread acceptance. Indeed, ecological speciation seems so rampant in Canadian fishes (sticklebacks, coregonids, salmonids, osmerids, and centrarchids) that one can get the impression of ubiquity. Eager to ride on the coat-tails of this exciting work, I have used similar methods to investigate ecological speciation in lake/stream stickleback and in Trinidadian guppies. Much to my initial dismay, I have failed to find simple and strong signatures of ecological speciation. Setting aside the possibility of personal incompetence, my failure to duplicate previous results may simply reflect a positive bias in the reporting of ecological speciation. In retrospect, such a bias seems obvious given that essentially all published studies of ecological speciation are confirmatory, whereas many populations in different environments likely show little, if any, hint of incipient speciation. I argue for the merits of further work on populations that show little evidence of ecological speciation, thus enabling analyses along a continuum from zero to complete reproductive isolation. This comparative approach may help inform the conditions that promote and constrain ecological speciation. Of particular importance may be the nature of mating systems, the amount of dispersal, the role of competition, and the genetic basis for adaptation and reproductive isolation.