History
There are several distinct strains of the virus, some are pathogenic and some are not. The most common are a European strain and a North American strain.
Genetic research into the ISA virus shows that the European and North American strains of the virus diverged from each other sometime around 1900. This research points out that starting in 1879 when rainbow trout were first brought to Europe from North America, there were many transfers of fish across the Atlantic ocean which may have carried the ISA virus. Some species were introduced to Europe from North America, and some species were introduced to North America from Europe. Given that the virus did not evolve into two separate strains until around 1900, and given how many transfers of fish there were, according to this research, "At present it is therefore not possible to suggest a geographical origin of the ISA virus."
Another study suggests that this virus was introduced into Norway between 1932 and 1959 and that the original strain was the European subtype found in North America. The strains found in Chile were transmitted from Norway between 1995 and 2007.
Read more about this topic: Infectious Salmon Anemia Virus
Famous quotes containing the word history:
“Regarding History as the slaughter-bench at which the happiness of peoples, the wisdom of States, and the virtue of individuals have been victimized—the question involuntarily arises—to what principle, to what final aim these enormous sacrifices have been offered.”
—Georg Wilhelm Friedrich Hegel (1770–1831)
“the future is simply nothing at all. Nothing has happened to the present by becoming past except that fresh slices of existence have been added to the total history of the world. The past is thus as real as the present.”
—Charlie Dunbar Broad (1887–1971)
“What has history to do with me? Mine is the first and only world! I want to report how I find the world. What others have told me about the world is a very small and incidental part of my experience. I have to judge the world, to measure things.”
—Ludwig Wittgenstein (1889–1951)