At the beginning of life, a community of early replicons (pieces of genetic information capable of self-replication) existed in proximity to a food source such as a hot spring or hydrothermal vent. This food source also produced lipid-like molecules self-assembling into vesicles that could enclose replicons. Close to the food source replicons thrived, but further away the only non-diluted resources would be inside vesicles. Therefore, evolutionary pressure could push replicons along two paths of development: merging with a vesicle, giving rise to cells; and entering the vesicle, using its resources, multiplying and leaving for another vesicle, giving rise to viruses.
This is one piece of evidence of co-evolution of cells and viruses, that communities of reproducing molecules actually pre-date cells.
here's an HN friendly paper discussing the origin of life via information theory:
https://doi.org/10.1016/j.jtbi.2019.03.009.
https://www.sciencedirect.com/science/article/pii/S002251931...
this paper is the cite for this section of the wikipedia article:
https://en.wikipedia.org/wiki/Viral_evolution
At the beginning of life, a community of early replicons (pieces of genetic information capable of self-replication) existed in proximity to a food source such as a hot spring or hydrothermal vent. This food source also produced lipid-like molecules self-assembling into vesicles that could enclose replicons. Close to the food source replicons thrived, but further away the only non-diluted resources would be inside vesicles. Therefore, evolutionary pressure could push replicons along two paths of development: merging with a vesicle, giving rise to cells; and entering the vesicle, using its resources, multiplying and leaving for another vesicle, giving rise to viruses.