Virology Image of viruses

Evolution is a complex process. Of course, we saw how viruses underwent antigenic changes, mutated their genomes and acquired new hosts, etc. But we did not observe any large-scale "changes in the way they are", because we knew about viruses only about 125 years. By changing them I think you mean either

1. A very significant change in the structure,

2. Acquisition of metabolism

3. Ability to live independently

4. Become a positive force in your host's life cycle, rather than causing disease. (This may have happened when retroviruses immunosuppressed placental mammals, allowing the embryo to be retained.)

Obviously, if viruses were driving these changes, we would most certainly say that they "evolved."

 If you do regular testing on HIV patients who are not taking their medications reliably enough, you can see the virus develop into a resistant strain.

@ekaterina-gribacheva ok, i got it)