Research Statement

Generally, my research addresses the processes that generate and maintain life-history variation across time and space, and the population genetic consequences of this variation.  Organisms express a diversity of solutions to the evolutionary problem of maximizing fitness in a changing world, and I have always been fascinated by the way life histories (phenology of maturity and reproduction, mating tactics, ontogenetic niche shifts) are able to respond to selection.  However, life history is also a fundamental component of population biology.  A major component of my research has been the use of molecular tools to understand the links between life history and historical demography, genetic diversity, population structure and connectivity, as well as the evolutionary consequences of anthropogenic change (e.g., introduced species, habitat fragmentation). 

More recently I have become interested in the genetic architecture of life history variation in ectotherms, particularly salmonid fishes.  Salmonids occupying dynamic (both short- and long-term) landscapes of temperate river systems often display a high degree of apparent local adaptation in morphological and phenological traits related to life history.  While strong philopatry increases the rate of local adaptation, most salmonid populations are very young in evolutionary terms.  We still do not know the relative contributions of heritable and environmental variation to ecotypic diversity found in salmonid populations, and greater understanding will require the integration of research across all scales of biological organization (from environmental conditions in whole drainages to intrapopulation variation at candidate genes).  This provides the opportunity to conduct collaborative research across disparate fields that seeks answers to fundamental questions in biology (how is biodiversity created and maintained?), while simultaneously addressing issues of societal importance in the Pacific Northwest (how does ecotypic diversity support sustainable salmon populations? How can we conserve and restore salmonid biodiversity?).

Current Research

My current research focuses on questions regarding the evolution of life-history variation in riverine fishes.

Candidate genes in the evolution of anadromy
Anadromous (“steelhead”) and resident forms of the rainbow trout (Oncorhynchus mykiss) are widely regarded as distinct entities.  However, recent use of genetic tools has shown that in the absence of anthropogenic barriers to dispersal and cross-basin transfers, the two forms often constitute a single population.  This does not mean that anadromy is entirely plastic; genomic variation can produce individuals that are more or less likely to adopt the anadromous tactic in a given environment.  Due to the exponential increase in fecundity gained by going to sea and growing large, females are more likely than males to be anadromous.  Rice’s (1989) hypothesis of sexually antagonistic selection predicts that traits with opposing fitness consequences in males versus females are likely to be located on the sex chromosomes.  In collaboration with Dr. Fred Allendorf (University of Montana), I am using microsatellites linked to the non-recombining sex-determining region to test the hypothesis that sex-linked variation in microsatellites sorts with life history in populations of O. mykiss from Kamchatka and Alaska that exhibit both resident and anadromous forms.  We are also exploring natural variation in other autosomal candidate genes and QTL associated with anadromy.

Genetic diversity, population structure, and ecotypic diversity in complex riverscapes
With my river ecologist/geomorphologist colleagues at Flathead Lake Biological Station, I am exploring the link between physical complexity of floodplain river systems and genetic/ecotypic diversity and population structure in salmonid fishes. Unconstrained rivers display a diversity of habitat types due to the dynamic nature of channel position and three-dimensional connectivity across the floodplain.  This habitat diversity in turn supports a diverse and productive riverine ecosystem, which is expected to support high productivity of salmonids, high effective population sizes (Ne), and thus high genetic diversity.  Complexity of habitats also provides greater opportunity for adaptation to local spawning and rearing conditions.  However, habitat dynamism might also lead to greater fluctuations in population size (driving down Ne) and might limit the scale at which populations can locally adapt.  As part of the Salmonid Rivers Observatory Network (SaRON) project supported by the Gordon and Betty Moore Foundation, we are using remote sensing to classify rivers by physical complexity around the Pacific Rim.  We are then comparing genetic diversity, population structure, and ecotypic diversity of rainbow trout/steelhead (Oncorhynchus mykiss) within and among rivers of varying degree of complexity to test hypotheses about the opposing effects of habitat diversity and dynamism on salmonid population structure and diversity.

Ecotypic diversity of sockeye salmon in floodplain systems
Sockeye salmon (Oncorhynchus nerka) are often associated with large, stable nursery lakes that typically comprise the primary unit for population genetic structure. The fine-scale genetic structure of lake-type sockeye salmon is paralleled by fine-scale ecotypic structure – and this complexity in life history/morphological traits appears to confer regional fishery stability via the portfolio effect (see Hilborn et al. 2003, PNAS 100:6564).  Riverine sockeye salmon, however, often exhibit greater genetic diversity within rather than among populations, probably as a consequence of increased straying in a more dynamic floodplain environment.  We are exploring the distribution of genetic and ecotypic diversity in both riverine and lake-type sockeye salmon of the Kuskokwim River system in western Alaska.  We have found that riverine sockeye salmon in this system follow the expected pattern of increased genetic diversity within and decreased genetic divergence between populations.  In on-going research funded by the Arctic-Yukon-Kuskokwim Sustainable Salmon Initiative, we are exploring how ecotypic (life-history and morphological) diversity is arrayed within and among populations of both riverine and lake-type forms in the Kuskokwim drainage. A finding of little divergence in ecotypic traits across the landscape might suggest a more volatile fishery at the regional scale, with individual populations responding to environmental fluctuations in a correlated, rather than complementary, fashion.

Education

• Ph.D. Biology, University of New Mexico, August, 2003
  Dissertation Title: Dominance and Invasive Species: the Roles of Dispersal and Body Size in the Displacement of a Native Fish by an Introduced Congener.
  Advisor: Thomas Turner, Assistant Professor.

• B.S. Fisheries (Magna cum laude), University of Washington, March 1996

Positions Held

• 2007 – present Assistant Research Professor, Flathead Lake Biological Station, The University of Montana
• 2006 - 2007 Postdoctoral Scholar, The University of Montana
• 2003  - 2005 Postgraduate Researcher, University of California, Irvine
• 2003 - 2003 Research Assistant, University of New Mexico
• 2000 - 2002 Environmental Specialist, SWCA Environmental Consultants
• 1997 - 2002 Graduate Teaching Assistant, University of New Mexico
• 1999 - 2000 Research Assistant, University of New Mexico
• 1996 - 1997 Biological Technician (Fisheries), U. S. Forest Service Pacific  Northwest Research Station
• 1996 - 1996 Fisheries Technician, School of Fisheries, University of Washington
• 1994 - 1997 Fisheries Technician, Fisheries Research Institute, University of Washington

2009 - Guest lecturer, The University of Montana

• Advanced Population Genetics (BIOL 595): “Natural selection”
• Research Design (WBIO 540): “Defining population structure using molecular markers”
  

2008 - Co-instructor (with F. W. Allendorf), The University of Montana

• Genetics and Evolution (BIOL223)

2007 - Guest Lecturer, The University of Montana

• Ecosystems Theory (BIOL 595): “Genetics and evolution in landscapes”
• Conservation Ecology (BIOL 452): “Temperature and development in ectotherms: implications for ecotypic diversity”
  

2006 - Teaching Assistant/Guest Lecturer, The University of Montana

• Conservation Genetics (BIOL 480)

1997 - 2002 - Teaching Assistant, University of New Mexico                      

• Ichthyology Laboratory (BIOL 487L)            
• Genetics Problems (BIOL 222)
• Introductory Biology Laboratory (BIOL 122L)
• Human Anatomy and Physiology Laboratory (BIOL 248L)
• Guest Lecturer, General Vertebrate Zoology (BIOL 386)

2007    Polly Gibson, NSF Research Experience for Undergraduates program.
Project: Effects of diet differences on the development of boreal toads (Bufo boreas). (Co-mentored with Dr. Fred Allendorf.)

2006 Megan Phillips, NSF Research Experience for Undergraduates program.
Project: Variation in candidate genes between resident and anadromous Oncorhynchus mykiss. (Co-mentored with Dr. Fred Allendorf.)

Peer-Reviewed Publications

• McPhee, MV and TF Turner.  Genealogical diversity suggests multiple introductions of white sucker (Catostomus commersonii) into the Rio Grande, New Mexico. Southwestern Naturalist, in press.
• McPhee, MV, MS Zimmerman, TD Beacham, BR Beckman, JB Olsen, LW Seeb, and WD Templin. A hierarchical framework to identify influences on Pacific salmon population abundance and structure in the Arctic-Yukon-Kuskokwim region. Sustainability of the Arctic-Yukon-Kuskokwim salmon fisheries: what do we know about salmon ecology, management, and fisheries? American Fisheries Society Symposium, in press.
• Utter, FM, MV McPhee, and FW Allendorf.  The role of population genetics in the management of Arctic-Yukon-Kuskokwim salmon populations. Sustainability of the Arctic-Yukon-Kuskokwim salmon fisheries: what do we know about salmon ecology, management, and fisheries? American Fisheries Society Symposium, in press.
• Stephenson, JJ, MR Campbell, JE Hess, C Kozfkay, AP Matala, MV McPhee, P Moran, SR Narum, MM Paquin, O Schlei, MP Small, DM Van Doornik, and JK Wenburg. 2008. A centralized model for creating shared, standardized, microsatellite data that simplifies inter-laboratory collaboration. Conservation Genetics: DOI 10.1007/s10592-008-9729-4.
• Turner TF, TE Dowling, MV McPhee, C Secor, RE Broughton, and JR Gold.  2008. Polymorphic microsatellite primers for the endangered sucker, Xyrauchen texanus (Catostomidae), are useful for hybridization studies of other catostomids.   Conservation Genetics: DOI 10.1007/s10592-008-9563-8.
• McPhee, MV, MJ Osborne, and TF Turner.  2008. Genetic diversity, population structure and   demographic history of the Rio Grande sucker, Catostomus (Pantosteus) plebeius, in New Mexico.  Copeia 2008:191-199.
• McPhee, MV, F Utter, JA Stanford, KV Kuzishchin, KA Savvaitova, DS Pavlov, and FW Allendorf. 2007. Population structure and partial anadromy in Oncorhynchus mykiss from Kamchatka: relevance for conservation strategies around the Pacific Rim.  Ecology of Freshwater Fish 16: 539-547.
• Kanda, N, M Goto, H Kato, MV McPhee, and LA Pastene.  2007. Population genetic structure of Bryde’s whales (Balaenoptera brydei) at the international oceanic and trans-equatorial levels. Conservation Genetics 8: 853-864.
• McPhee, MV.  2007. Age, growth and life history comparisons between the native Rio Grande sucker (Catostomus plebeius) and the invasive white sucker (Catostomus commersoni) in the Rio Grande, New Mexico.  Southwestern Naturalist 52: 15-25.
• Moyer, GM, TF Turner, MV McPhee, and KO Winemiller. 2005. Historical demography, selection, and coalescence of mitochondrial and nuclear genes in Prochilodus species of northern South America. Evolution 59: 599-610.
• McPhee, MV and TF Turner. 2004. No genetic evidence for hybridization between Rio Grande sucker, Catostomus plebeius, and the introduced white sucker, Catostomus commersoni, in the Upper Rio Grande of New Mexico. Environmental Biology of Fishes 71: 85-93.
• Turner, TF, MV McPhee, P Campbell, and KO Winemiller.  2004. Phylogeography and intraspecific genetic variation of prochilodontid fishes (Characiformes) endemic to rivers of northern South America. Journal of Fish Biology 64: 186-201.
• McPhee, MV and TP Quinn. 1998. Factors affecting the duration of nest defense and reproductive lifespan of female sockeye salmon, Oncorhynchus nerka. Environmental Biology of Fishes 51: 369-375.
• Quinn, TP and MV McPhee. 1998. Effects of senescence and density on the aggression of adult female sockeye salmon. Journal of Fish Biology 52: 1295-1300.

• McPhee, MV (2003) Population genetic structure and diversity in populations of Rio Grande sucker (Catostomus plebeius) in three neighboring streams on the Ladder Ranch, Sierra County, New Mexico. Report to Turner Ranch Properties, LLC.
• Turner, TF, MV McPhee, D Alò, and WH Brandenburg (2003) Determination of occurrence of hybridization of San Juan River razorback sucker through genetic screening of larval fishes. Report to the Bureau of Reclamation, Albuquerque, NM.