Retroviruses emerged by transforming “jumping genes” into infectious agents, mastering the ability to rewrite a host’s permanent genetic code.

Appearing as complex eukaryotes diversified, Retroviruses evolved by equipping mobile genetic elements (retrotransposons) with “stolen” structural proteins. Using the enzyme reverse transcriptase, they flip the flow of information from RNA back into DNA, allowing them to stitch themselves permanently into the host’s genome and hide for generations.