3 leading hypotheses for the evolutionary ORIGINS of VIRUSES:  (1) VIRUS-FIRST HYPOTHESIS -           is the notion that viruses came into existence before cells,           somehow assembling themselves directly from that primeval           cookery. (2) ESCAPE HYPOTHESIS -           suggests that genes or stretches of genes leaked out of           primordial cells, became encapsulated with protein capsids,           and went rogue, finding new niche as parasites.  (3) REDUCTION HYPOTHESIS -         reduction hypothesis suggests that viruses originated when         some cells downsized under competitive pressure (it being         easier to replicate if you’re small and simple), shedding genes         until they were reduced to such minimalism that only by         parasitizing cells could they reproduce.

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