We reached the conclusion in an earlier post that viruses are obligate intracellular parasites. These three somewhat confusing words mean they can only ensure their survival by living and replicating inside host cells. If we could stop COVID-19 spreading between people the virus causing the disease could die out. Today we move on to an overview of the evolution of viruses.
Three Theories Suggesting Where Viruses Came From
We are delving into advanced biological science, and can only provide an overview here. The first of the three theories suggests viruses are clusters of genetic elements that progressively learned to move between cells.
However, the second hypothesis for the evolution of viruses sees things differently. It holds viruses are leftover bits from cellular organisms that regressed to their current state. Both these theories assume the viruses arrived after their hosts.
But there is also a third theory. This argues that viruses existed before their host cells arrived, or co-evolved in parallel with them. In fact, some supporters of this theory suggest viruses may have been the first organisms able to replicate themselves.
None of These Fully Explain the Evolution of Viruses
We’ll be reporting on these three theories in more detail in future posts. However, at this stage we should like to note that none of them explain the origin of viruses completely. For if they did, their evolution would not attract the interest it does.
The idea viruses evolved over time is attractive, because it fits well with the theory of the evolution of the species. However, the thought that viruses were the beginning of life as we know it is even more intriguing. Although as we said there is no single hypothesis that answers all our questions simultaneously.
Previous Posts
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How the Virus Jumped from Animals to People
Preview Image: A Virus Replication Cycle
