Table 7.1.

Some representative rates of virus evolution in nature.

Virus or organism	Range of values
RNA viruses (riboviruses)	10−2 to 10−5
Retroviruses	10−1 to 10−5
Single-stranded DNA viruses	10−3 to 10−4
Double-stranded DNA viruses	10−7 to 10−8
Cellular genes of host organisms	10−8 to 10−9

Values are expressed as substitutions per nucleotide and year. The range of values is based on several studies. Values depend on the virus or organism under study, the genomic region analyzed, and several factors discussed in the text.