The Genetic Variation of Salmon
Pacific Salmon Hold the Pacific Northwest in Their Genes
North American salmon have survived tens of thousands of years of geological and climatic upheaval, leading them to evolve considerable genetic variation.
It is persistence incarnate: a salmon, fighting against a rushing falls, seeking to regain the waters of its birth. Yet there more to this iconic image than meets the eye. It is, in fact, as illustrative of the species toughness at an evolutionary level as it is the tenacity of any individual fish.
The Nature of Salmon
Like all living things, salmon have a dualistic nature. For any given salmon, there is tucked away in each of its cells a full genetic DNA blueprint of the fish (its genotype.) The fish itself is the expression of the instructions contained within that blueprint, as it interacts with the physical environment (the phenotype.) Thus a salmon’s entire development, physiological processes, and behavior are not only a function of the world it lives in, they are also directly or indirectly controlled by the information encoded in the blueprint hidden within its cells.
All life forms are historical phenomena. A salmon, unique at the molecular level because of its particular DNA, represents a storehouse of information won over generations. Any fish that survives Nature’s obstacle course long enough to spawn, essentially does so because it possesses a combination of characteristics, coded for by their DNA, that favor them and helps it to survive the environmental challenges faced throughout its life. This potentially winning biological heritage is then passed to any offspring for their own match with Nature.
Genetic Heritage
North American salmon’s individual and population gene pools represent an accumulated and retained history of their species for thousands, perhaps even millions of years.
During that time, throughout their range in Alaska and the Pacific Northwest, climates have changed, mountains raised, coastlines migrated, glaciers surged—yet salmon endure. The collective genes of today’s salmon species represent a library holding thousands of years of evolutionary experience—valuable molecular lessons on how to survive in a dynamic world.
References
Alaska Geographic. 1994. Prehistoric Alaska. Vol. 24, no. 4. Alaska Geographic Society, Anchorage, AK.
Brown, Bruce. 1990. Mountain in the Clouds: In Search for the Wild Salmon. University of Washington Press. Seattle, WA.
Frissel, C.A. 1989. Evolution of the Salmonid Fishes: Zoogeography and the Fossil Record. Department of Fisheries and Wildlife, Oregon State University, Corvallis.
Groot, C. and L. Margolis. 1991. Preface. In Pacific Salmon Life Histories. Edited by C. Groot and L. Margolis, pp ix – x. UBC Press, Vancouver, Canada.
Janovy Jr., John. 1996. On Becoming a Biologist. University of Nebraska Press, Lincoln, NE.
Lichatowich, Jim. 1999. Salmon Without Rivers: A History of the Pacific Salmon Crisis. Island Press, Washington D.C.
