|MadSci Network: Virology|
Viruses are found, most of the time, in close harmony with their host. Hundreds of human viruses are asymptomatic, and about 3% of the so- called "junk" DNA of the human genome is of viral origin.
The speed of replication is mainly dependant on the polymerase speed, and I assume this is more or less the same everywhere (note that RNA polymerases are slower than DNA-dependant DNA polymerases).
On the other hand, the speed at which a symptom is shown depends on the virus and the host. You can easily conclude that "good" viruses do not kill their host, as this host maintains them and allows them to multiply. Viruses that are not well adapted to their host tend to destroy the hosts (these are known as diseases) and eventually kill them. This is what happens when a virus "jumps" from one species to another one. These viruses usually never fix in a population, because the chance is high that an infected individual dies before having infected somebody else...
More precisely, the literature seems to be quite poor on this subject, and I would guess the Filoviridae family (Ebola, etc.) to be the winners, as an infected human usually develops haemorrhagic fever within 2 days and dies shortly after...
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