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Published on: September 27, 2014
Defining life: the virus viewpoint.
1CNRS UMR 8621 Institut de Génétique et Microbiologie, Univ Paris-Sud, 91405 Orsay Cedex, France. forterre@pasteur.fr
Summary
Viruses are increasingly recognized as living entities, playing a key role in evolution. This study proposes defining life as an historical process encompassing both cellular and viral organisms.
Area of Science:
- Virology
- Evolutionary Biology
- Astrobiology
Background:
- Historically, viruses were not considered alive, excluding them from origin of life discussions.
- Recent discoveries highlight viruses' significant role in the evolution of cellular organisms.
- A distinction is now made between viruses and virions, viewing viruses as complex entities.
Purpose of the Study:
- To propose a new definition of life that includes viruses.
- To redefine the concept of an organism to encompass viral entities.
- To discuss the origin of life based on this expanded definition.
Main Methods:
- Conceptual analysis of existing definitions of life and viruses.
- Integration of recent virological and evolutionary findings.
- Proposal of new definitions for life and organism.
Main Results:
- Viruses are viewed as living entities that create novel virus-producing organisms when infecting cells.
- Life is defined as the historical process of ribosome-encoding (cellular) and capsid-encoding (viral) organisms and their ancestors.
- An organism is defined as integrated molecular or cellular organs producing individuals that evolve via natural selection.
Conclusions:
- The proposed definitions provide a framework for including viruses in discussions about life's origins and evolution.
- The origin of life on Earth is linked to the establishment of the first organism fitting the new definition.
- This perspective reframes viruses as fundamental players in the history of life.
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