Keyword: Ecology and evolution
My recent research includes detecting genetic and phenotypic variations of a common toad (Bufo gargarizans) along elevational gradients, establishing associations between them, and understanding how these variations may have contributed to the adaptation process. I am also studying the Phrynocephalus lizards, particularly their signal evolution, special adaptation to high-elevation environment (5000m), and population genetics and speciation. I also plan to return to one of my favorite research topics, the evolution of unisexuality in the Caucasian rock lizards (Darevskia).Learn More
We address questions about how biodiversity arises in single populations of fishes composed of alternate ecotypes that live in different lake habitats. We study the factors that regulate the formation of specialized ecotypes and have expanded theory by evaluating the role of phenotypic plasticity in adaptive divergence. Experience with fish resource polymorphism since 1993 uniquely positions us to investigate how different ecotypes evolve and may be converted into new species. We also study the effects of commercial fishing on natural populations. This work is important because diversity within populations is rarely considered in the contexts of ecological function, management and conservation, or its capacity to buffer populations from adverse effects of environmental change.Learn More
A current focus of our coalescent-based work is the development of models to support inferring historical processes that shape an ecological community, from genes to ecosystem processes. These models have applications across the domains of life, from microbial communities to grasslands. A corollary to this work is theory in support of the interpretation of metagenomic data. In the area of polyploid population genetics, our work is currently focusing on models of multilocus selection, with potential application to understanding the evolution of recombination rates and diploidization.Learn More
Research in the Crease lab uses freshwater crustaceans in the genus Daphnia as a model organism to study evolution of the ribosomal (r)DNA multigene family, and of the DNA transposon, Pokey, which inserts in a specific region of the Daphnia rDNA repeat as well as other genomic locations. Current projects involve comparing rates of evolution in ribosomal proteins that bind to conserved and variable regions of rRNA genes, determining the impact of breeding system (cyclic or obligate parthenogenesis) on the evolution of rDNA and Pokey transposons, determining the relationship between rDNA copy number and Pokey distribution, and measuring rates of Pokey transposition inside and outside of rDNA.Learn More
My research program investigates the ecological and evolutionary processes operating in plant populations, both wild and domesticated. Much of our work is conducted through the lens of plant reproductive systems, which control the quantity and quality of sperm and eggs, patterns of mating, and ultimately the transmission of genetic variation from one generation to the next. Current research projects include: 1) mating system variation and evolution, 2) polyploid speciation, 3) genetic and phenotypic consequences of whole genome duplication; 4) biology of small populations, and 5) impacts of hybridization between introduced species and endangered congeners. We work on a variety of study systems, including Arabidopsis, apple, strawberry, fireweed, American chestnut, and mulberry.Learn More
In the next 5 years, I will shift my research strategy by consolidating 4 streams of my past research: temporal dynamics, host-symbiont interactions, small mammal metacommunity dynamics, and DNA-based species identification and bioinformatics. I will focus on a study system that combines my past strengths in metacommunity ecology at multiple scales, but will apply them to a novel system: microbial metacommunities nested within a matrix of metacommunity of different host species.Learn More
In eastern Canada, the lumpfish and a North American wrasse, the cunner, significantly reduce adult lice densities on salmon living in marine sea cages. My group's work has the following objectives: 1) determine the best size-class of cunners to use in commercial sea cages; 2) examine variation in lice-cleaning performance among cunners and among lumpfish from different stocks; 3) assess heritable variation in lice eating behaviour; 4) Conduct lice challenges of pedigreed salmon with and without the lice cleaner fish present.
3) Increased sea surface temperatures have allowed larval shore crab to invade western Canadian shores and prey on indigenous snail species. We are identifying genomic changes correlated with adaptation to predators in a 25 year field experiment near Bamfield, BC.