previrus
A previrus is a theoretical intermediate stage in the origin of life, specifically in the development of viruses. The concept proposes that viruses did not originate as independent entities but rather evolved from components of cells that escaped or were released. In this model, genetic material, possibly DNA or RNA, along with some basic protein components, would have become encapsulated within a lipid membrane derived from a host cell. This encapsulated entity would then exist in a state prior to the full development of a replicative cycle, relying heavily on host cell machinery for any form of propagation.
The previrus hypothesis suggests that such entities would have gradually acquired the ability to infect other