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Which hypothesis about the origin of viruses proposes that they descend from free-living cells?
ADevolution, also called regressive
BEscapist, also called progressive
CMolecular systematics comparison
DSelf-replication alongside hosts
Answer & Solution
Correct answer: A. Devolution, also called regressive
1. Three hypotheses compete over where viruses came from.
2. The devolution or regressive hypothesis says viruses evolved from free-living cells that lost their independence.
3. The escapist or progressive hypothesis instead says viruses began as nucleic acids that escaped a host cell.
4. A third idea has viruses self-replicating alongside the cells they depend on.
5. Virus molecular systematics is a field of study rather than an origin hypothesis, so it is not the answer.
_Source: OpenStax Biology (1st ed., CC BY 4.0), Ch 21 "Viruses", section 21.1 Viral Evolution, Morphology, and Classification_
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