Question: How does a virus start?

Amal Lavender answered on 24 Feb 2021:

great question and very hard as there is no one single theory on this – The technology and resources we have today cannot confidently test these theories and identify the most plausible explanation for the origin of viruses.
One theory hypothesizes that viruses arose from circular DNA (also called a plasmid) that can replicate independently and move between cells, transferring genetic information from one organism to another
a second theory suggests that viruses could have evolved from more complex free-living organisms, such as bacteria, or cells
lastly a third different hypothesis proposes that viruses existed first, even before cells. In a prehistoric world, viruses might have existed as self-sustaining entities, a sort of ancient machine that could probably reproduce its genetic material. Over time, these prehistoric viruses may have formed complex, organized structures that eventually evolved into cell-like entities.