Evolution
All extant rabies viruses appear to have evolved within the last 1500 years. Consequently, the emergence of rabies may have been contemporaneous with the extreme weather events of 535–536 and/or the eruption of Krakatoa.
There are seven genotypes of rabies virus. In Eurasia cases are due to three of these - genotype 1 (classical rabies) and to a lesser extent genotypes 5 and 6 (European bat lyssaviruses type-1 and -2). Genotype 1 evolved in Europe in the 17th century and spread to Asia, Africa and the Americas as a result of European exploration and colonization.
Read more about this topic: Rabies Virus
Famous quotes containing the word evolution:
“By contrast with history, evolution is an unconscious process. Another, and perhaps a better way of putting it would be to say that evolution is a natural process, history a human one.... Insofar as we treat man as a part of nature—for instance in a biological survey of evolution—we are precisely not treating him as a historical being. As a historically developing being, he is set over against nature, both as a knower and as a doer.”
—Owen Barfield (b. 1898)
“Analyze theory-building how we will, we all must start in the middle. Our conceptual firsts are middle-sized, middle-distanced objects, and our introduction to them and to everything comes midway in the cultural evolution of the race.”
—Willard Van Orman Quine (b. 1908)
“The more specific idea of evolution now reached is—a change from an indefinite, incoherent homogeneity to a definite, coherent heterogeneity, accompanying the dissipation of motion and integration of matter.”
—Herbert Spencer (1820–1903)