Are viruses nature’s perfect machine? Or alive?
|February 26, 2016||Posted by News under Cell biology, News, Origin Of Life|
Machine, argues Josh Bloom at American Council for Science and Health:
I recently wrote that viruses do not come even close to meeting the standards that are generally accepted requirements in defining what “alive” means.
But they do have a huge impact on living organisms, because they are miracles of evolution — microbes that exist solely to reproduce, and do so with perfect efficiency and no waste.
What this “bag of chemicals,” which is about 100-times smaller than a bacterium, does is nothing short of amazing. It is way “smarter” than the cell that it infects. Using nothing more than a very specifically-shaped protein spike to locate and attach itself to the host cell, its own genetic material, and a few enzymes, each of which has a specific function, it turns the cell into a virus factory, letting the cell do all the work. The virus does nothing, except reproduce, courtesy of the cell, which provides the energy and the mechanism for viral replication. This is why viruses are called obligate parasites. They do not function in the absence of a host cell. More.
But is “machine” the right analogy? Machines don’t do anything, absent instructions, and can’t be “smart,” though we sometimes call those who design them smart.
Plus, there is reason to believe that at least some viruses are in fact devolved cells.
There is considerable sympathy these days for the idea that viruses are in fact alive:
Arshan Nasir, who is Caetano-Anollés’ graduate student and also worked on the study, added that “viruses are living. They simply have an atypical mode of living that is slightly different from ours. They are not fully independent. Instead, they move in and out of our bodies, stealing the resources and producing their offspring. In short, we need to broaden how we define life and its associated activities.”
Viruses are challenging to study because the sequences that encode their genomes are subject to rapid change. As a result, the scientists elected to study what are known as “folds”: the structural building blocks of proteins that give proteins their complex, three-dimensional shapes. (Discovery, 2015)
Apart from anything else, this isn’t good news for gene fundamentalism.
Viruses demonstrate a key quality of life forms: They try to stay alive and reproduce. Boulders do not try to avoid becoming gravel. Thoughts?
See also: Devolution: Getting back to the simple life
What can we hope to learn about animal minds?
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How viruses infect cells: