sentences:  One theory of how the European Eyach virus is proposed to have come about in Europe is by the migration of lagomorphs from North America over fifty million years ago.Since then, the virus took on some differences, and is now considered its own species of virus.European Eyach virus was isolated in 1976 from "Ixodes ricinus" ticks in Europe and in 1981 from the same species along with "Ixodes ventalloi" in 1981.