|Panspermia is an ancient idea that supports the existence of life throughout the Universe. Panspermia proposes that life that can survive the effects of space get distributed in all habitable and non-habitable planets by meteoroids, asteroids and planetoids across the Universe. Extremophilic micro-organisms known to survive and thrive in extreme conditions on earth also pose a possibility of existing in other parts of universe delivered by comets or asteroids. Viruses, being simple organisms, are also capable of such survival and journeys across space. Viruses are known to be mobile genetic elements and install new genes into their host cells supporting the evolutionary mechanism. The origin of life on earth has for long been debated. This is probably one of the biggest puzzles in biology and science which is yet to be fully understood. Panspermia is a highly controversial theory that proposes the theory of origin of life on earth hypothesizing the arrival of life on earth from outer space. Extremophilic microorganisms capable of surviving in extreme conditions have been proposed to travel far into space unaffected by means of cometary materials and subsequently been proposed to flourish in a distant planet that harbours favourable conditions. Viruses which are a simple form of life are hypothesized to be potential candidates for space travel. The theory of panspermia have been supported by examples of different viruses, their predicted origin and spread on the earth as well as ability to carry out horizontal gene transfer to answer questions of origin of life on earth and its subsequent evolution to higher forms. This article will attempt to address the understandings of the theory of panspermia and the roles of viruses in supporting this theory.
Koushik Chattopadhyay, The Role of Viruses and Viral Infections in the Theory of Panspermia