Corey C. Phillis bio photo

Corey C. Phillis

Ecology, Evolution, Migration, and Salmon. Postdoc at the NOAA Fisheries NWFSC

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I am currently a postdoc in the Watershed Program at the Northwest Fisheries Science Center in Seattle , WA.


I am interested in understanding the scales of diversity that are important in ecology. To date, the bulk of theoretical and empirical research on diversity has been focused at the species level, no doubt largely because this is the scale of diversity most readily identifiable and compartmentalized. While this research has greatly advanced our understanding of the relationship between diversity and stability in ecological systems, it seems shortsighted to let the species concept limit our scope of inquiry. The most commonly applied definition of a species (the Biological Species Concept) elevates reproductive isolation as the litmus test, while permitting a great degree of within species diversity (e.g. local adaptation, polyphenisms, life-history diversity) and across species commonality (functional trait redundancy via parallel or convergent evolution). It is the ecological importance and evolutionary origin of these sometimes overlooked scales of diversity that interest me.

Study System

I utilize Pacific salmon (Oncorhynchus spp.) as a study organism because they exhibit a great degree of within species diversity. Anadromy— where individuals breed in freshwater after completing somatic growth and reaching maturity at sea —is an ecologically important life-history common to all Pacific salmon. However, this life history is not fixed in all species within the Pacific salmon. For instance, rainbow trout (below left) will complete their full life-cycle in freshwater; steelhead (below right) will migrate to sea before returning to freshwater to spawn; both are variants of the same species (O. mykiss). Given their wildly divergent life histories, do rainbow trout and steelhead alter freshwater ecosystems differently? Or are these two forms ecologically equivalent?


I use a mix of controlled breeding studies, model simulations, and experimental field manipulations to test the genetic dependence of anadromy, the rate at which it can evolve, and the degree to which ecosystem processes are dependent on the life history form present.


This work has particular application for the restoration and management of populations wherever human-altered landscapes (e.g. dams, thermal regimes, fishing pressure, etc) threaten anadromous salmon migrations and favor the resident life history form.