EXTINCTION OR EVOLUTION OF POPULATIONS AFTER A CHANGE IN THE ENVIRONMENT
The current rates of environmental change experienced by animal populations are higher than have been experienced over much of fossil record. My laboratory investigates the factors that determine whether a population will adapt to a change in the environment without going extinct.
Current Project 1: Invasion Biology: Comparing Scales of Local Genetic Adaptation to Exotic Predators by Prey with High and Low Dispersal Potential (with Karen Rickards and David Hunt)
Environmental change caused by human activities is allowing exotic predators and competitors to extend their geographical ranges into Canada. For example, increased sea surface temperatures during the 1997/98 El Niño allowed larvae of the subtropical lined shore crab to metamorphose on western Canadian shores and prey on four closely-related species of indigenous snails. These temperate snail species have shells that are vulnerable to the specialized shell-breaking appendages of predators from more tropical regions. Consequently, climate-driven range expansion of subtropical predator species may result in range contraction by temperate prey species unless they can quickly evolve thicker armour. This is an excellent system for studying the effect of prey migration on adaptation to subtropical predators. These four intertidal gastropods are ecologically similar but differ considerably in their dispersal potential: two species have a long-lived free-swimming larval stage and two species have lost the free-swimming larval stage and as a result disperse only by crawling. My long term research program assesses the importance of rapid evolution in preventing populations from going extinct after changes in the environment. During this grant cycle, I will test the hypothesis that prey species with high dispersal can only adapt to predatory crabs that invade their entire geographic range. Consequently I predict that rapid evolution may be more important in preventing poorly-dispersing species from going extinct as these have lifetime dispersal distances of a few metres. I have three short-term objectives that will all compare Littorina species with and without a free-swimming larval stage: 1) To compare the minimum spatial scale of genetic adaptation to predators, 2) To compare the length of coastline occupied by a single population, and 3) To compare the amount of phenotypic plasticity in adaptive complex traits known to form clines. I plan to parameterize an extension of our individual-based quantitative genetic model which could also be useful for understanding the effect of dispersal on adaptive population differentiation in other systems. (funded by NSERC Discovery grants Ph.D. position available ).
Past Project 2: Integrating ecological research and hatchery operations for the restoration of the threatened northern abalone Haliotis kamtschatkana (M.Sc. graduates: Matt Lemay and Kaitlyn Read)
My laboratory's part in this research has been to improve outplanting strategies for rebuilding wild Northern abalone populations. Kaitlyn has evaluated the success of past outplanting efforts via non-lethal genetic identification of outplanted individuals in the wild using microsatellites protocols developed by Matt Lemay. Her genotyping suggests that past larval outplanting has been successful. Her work has also shown the importance of habitat-modification and predator control in facilitating the survival of outplanted hatchery-raised animals in the wild. By using a combination of laboratory and field techniques, we have gained important insights into the biology of this species. (past Funding: NSERC Strategic grant: PI: Dr. Louis Gosselin (Thompson Rivers University); co-investigators: Dr. Chris Harley (UBC) and myself for K. Read. Also past AQUANET (PI myself for Matt Lemay).
Aquaculture now produces all the Atlantic salmon consumed by Canadians and a significant amount for export. However, disease is a major constraint affecting the sustainability and profitability of this industry. Foremost is disease in marine farmed stock. Disease has a direct impact on farm income through inventory losses and an indirect impact by influencing consumer demand. Fortunately the rate of genetic improvement for functional traits such as disease resistance can be greatly improved by using a new method of animal breeding called genomic selection. This technique uses five thousand "SNP" genetic markers to determine which of the offspring produced by a disease-resistant family have inherited the disease-resistant alleles.. We are testing whether genomic selection can improve growth rate in saltwater, rapid adaptation to seawater, disease resistance and delay sexual maturity relative to a conventional breeding program currently used at Cooke Aquaculture Inc. in New Brunswick. We are accomplishing this within a three year period using archived fin-clip samples and estimated breeding values (EBVs) from current and past broodstock and their relatives, as well as the performance of their relatives in seawater farm cages. We will predict genetic changes in economically important traits that would accrue from the use of genomic selection, and compare this to current selection programs. Disease resistance is being determined by challenge of post smolts with the salmon louse and ISA by Dr. Brian Glebe's quarantine lab at Department of Fisheries and Oceans Canada’s St. Andrews Biological Station. (Funding: NSERC Strategic grant: PI: myself, co-investigators: Dr. L.R Schaeffer and Dr. P.T. Schulte, collaborators Cooke Aquaculture and Department of Fisheries and Oceans Canada.).
· Seamone, B., Boulding, E.G. in press. Aggregation of the Northern Abalone, Haliotis kamtschatkana, with respect to sex and spawning condition. J Shellfish Res XXX:XX.
· Freamo, H., O'Reilly, P., Berg, P.R., Lien, S., Boulding, E.G. 2011. Identification of non-neutral single nucleotide polymorphisms (SNPs) that confirm genetic structure between inner and outer Bay of Fundy metapopulations of Atlantic salmon (Salmo salar). Mol Ecol Res 11 (Suppl. 1), 254-267 (Special Issue: SNP Development in Non-Model Organisms).
· Naish K.A., Boulding, E.G. 2010. Corrigendum for Trinucleotide microsatellite markers for the Zebra Mussel, Dreissena polymorpha, an invasive species in Europe and North America. Mol Ecol Res 11:223-224.
· Pakes, D., Boulding, E.G. 2010. Changes in the selection differential exerted on a marine snail during the ontogeny of a predatory shore crab. J Evol Biol 23: 1613-1622. pdf preprint
· Lee, H.J., Boulding, E.G. 2010. Latitudinal clines in body size, but not in thermal tolerance or heat shock cognate 70 gene (HSC70) in the highly-dispersing intertidal gastropod, Littorina keenae (Gastropoda: Littorinidae). Biol J Linn Soc 100: 494-505. pdf preprint
· Lee, H.J., Boulding, E.G. 2009. Spatial and temporal population genetic structure of four northeastern Pacific littorinid gastropods: the effect of mode of larval development on variation at one mitochondrial and two nuclear DNA markers. Mol Ecol 18: 2165-2184. pdf preprint
· Lemay, M.A., Boulding, E.G. 2009. Microsatellite pedigree analysis reveals high variance in reproductive success and reduced genetic diversity in hatchery-spawned northern abalone. Aquaculture 295: 22-29 pdf preprint
· Boulding, E.G., deWaard J.R., Ang K.P, Hebert P.D.N. 2009. Population genetic structure of the salmon louse, Lepeophtheirus salmonis (Krøyer) on wild and farmed salmonids around the Pacific coast of Canada. Aqua Res 40: 973-979. pdf preprint
· Boulding, E.G. 2008. Genetic diversity, adaptive potential, and population viability in changing environments. pp. 199-219 In: Conservation Biology: Evolution in Action. Edited by Scott Carroll and C. Fox. Oxford University Press. ISBN13: 978-0-19-530679-8. pdf preprint
· Boulding, E.G., M. Culling, B. Glebe, P.R. Berg, S. Lien, and T. Moen. 2008. Conservation genomics of Atlantic salmon: SNPs associated with QTLs for adaptive trait differences in parr from four trans-Atlantic backcrosses. Heredity 101: 381–391. pdf reprint supplemental data
· Zahradnik, T. D., M. A. Lemay and E. G. Boulding. 2008. Choosy males in a littorinid gastropod: male Littorina subrotundata prefer large and virgin females. Journal of Molluscan Studies 74: 245–251. pdf reprint
· Boulding, E. G., T. Hay, M. Holst, S. Kamel, D. Pakes, and A. Tie. 2007. Modeling the genetics and demography of step cline formation: Gastropod populations preyed on by experimentally introduced crabs. Journal of Evolutionary Biology 20:1976–1987. pdf reprint supplemental data
· Lee, H. J., and E.G. Boulding. 2007. Mitochondrial DNA variation in space and time in the northeastern Pacific gastropod, Littorina keenae. Molecular Ecology 16: 3084–310. pdf reprint
· Grey, M., P. G. Lelièvre, and E.G. Boulding. 2007. Naticid gastropod prey selection of shell thickness on the bivalve Protothaca staminea (Conrad, 1837). Veliger 48: 317-322. pdf reprint
· Cassone, B.J., and E. G. Boulding 2006.Genetic structure and phylogeography of the lined shore crab, Pachygrapsus crassipes, along the northeastern and western Pacific coasts. Marine Biology 149:213-226. pdf reprint
· Grey, M., E.G. Boulding, and M. Brookfield. 2006. Estimating multivariate selection gradients in the fossil record: a naticid gastropod case study. Paleobiology, 32:100–108. pdf reprint
· Quinton, V.M., I. McMillan, J.J. Tosh, and E.G. Boulding. 2006. Breeding designs for a small-scale northern abalone hatchery. Conference Proceedings of the 8th World Congress on Genetics Applied to Livestock Production, April 13 to 18, 2006, Brazil. (published online July 2006).