Determining the first virus on Earth is impossible due to the lack of fossil evidence for viruses. However, the first virus discovered was the Tobacco mosaic virus (TMV).
- In 1892, Dmitri Ivanovsky used a Chamberland filter to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having passed through the filter. This suggested the presence of a pathogen smaller than bacteria, which was later confirmed by Martinus Beijerinck in 1898.
While TMV was the first virus discovered, scientists speculate that viruses existed long before the emergence of life on Earth. There are several hypotheses regarding the origin of viruses, including:
- The regressive, or reduction, hypothesis: This theory suggests viruses are remnants of cellular organisms that have lost complexity over time.
- The virus-first hypothesis: This theory proposes viruses existed before cellular life, possibly as self-replicating molecules.
While the origin of viruses remains a subject of ongoing research, it's clear that they have played a significant role in the evolution of life on Earth.
