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Viruses: Between Living and Inert
by Biol. Oscar S. Aranda Mena |
These particles are able to infect and kill any living organism on our planet, so the need to understand them is vital to our future. Defining VirusesViruses do not fall into any biological classification, since they are not made up of a complete cell, but they do possess genetic material like that of other animal or plant cells. Moreover, its structure has certain qualities that are remarkably similar to the mineral kingdom. Thus viruses exist somewhere between the inert and the living but are considered to be biological entities, because they do contain genetic information that can replicate and evolve. The word virus, in ancient Latin, was used to define excreta and natural fluids. It has since evolved to define an extremely small infectious agent that, until the 1930s, remained invisible to the human eye. After being isolated, it was discovered that viruses are larger than a molecule; a little larger than a single protein, and can even seep through typical ceramic filters. Living Parasites Although they possess a "package" of genetic information (DNA or RNA), a virus, alone, cannot live or grow. It needs a living cell as a host; it then seizes all its enzymes and biological machinery, using that cell to reproduce and auto-generate new capsules containing its own genetic information. Then it must be ready to emerge from the host to start a new cycle of infection in an uninfected cell. Virus Origins? Their origins are uncertain, because there have left no fossil record. One theory is more consistent with "co-evolution", where the virus evolved in tandem with life forms as "parasitic cells", which lost many of its components and that were originated in water, air and land; adapted to a particular way of life, so now there are very different and highly specialized viruses, capable of targeting a specific cell. The Virus Weakness After infecting a host cell, a virus is identified by the proteins that surround it and the host body is able to generate antibodies to detect and remove it, so its life cycle is very short, leaving the host in just a few days, but not before releasing innumerable replicas to attack other new cells. The Success of the Virus Viruses are an example of evolution at its best. Evolution is a gradual change in the structure of an organism to adapt to its environment over time, either by natural selection or mutation. A mutation is a random drastic change in its basic structure, which creates a new stable form and endless descendants. "New" viruses are regularly listed, which have altered the proteins that form the outer shell previously formed by the host its antibodies can no longer recognize it. This new, unknown virus is thus undetectable by potential hosts that are unable to defend themselves against this new invasion. The influenza virus is known to mutate frequently. Mankind has been unable to create an effective vaccine against colds or influenza, because, despite being very similar to one another, each "strain" of new virus proteins is different, having many variants so it has so far been impossible to create an effective vaccine for every variant. We are therefore often infected by the cold virus. The Present and the Future Many of the epidemics and pandemics in history have been caused by viruses such as smallpox and influenza in all their variations, Scientists are now preparing to face a newly emerging virus, that is fast becoming more aggressive and resistant. Climate change and overpopulation have favored the evolution of new viruses and bacteria, and many see them as nature attempting to control of the human population, seeking a balance. So we must pause and consider whether or not there are already too many people, or whether a more austere and ordered life-style would allow us to better deal with a future that threatens to be very complicated for everyone. We hope that advances in science will allow us to understand that the danger facing the planet is not from viruses but from ourselves. |
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