Saturday, 5 September 2020

Virus Intelligence

Can a virus have intelligence?

The new Coronavirus is a respiratory virus which spreads primarily through droplets generated when an infected person coughs or sneezes, or through droplets of saliva or discharge from the nose. Coronavirus can cause more severe symptoms in people with weakened immune systems, older people, and those with long term conditions like diabetes, cancer and chronic lung disease.

Viruses have ways to enter the human body [through the nasal passages, mouth, skin or via injection]. Many have evolved defenses to help them evade the immune system. Viruses that cause infection in humans hold a 'key' that allows them to unlock normal molecules [called viral receptors] on a human cell surface and slip inside. Once in, viruses commandeer the cell’s nucleic acid and protein-making machinery, so that more copies of the virus can be made.

For about 100 years, the scientific community has repeatedly changed its collective mind over what viruses are. First seen as poisons, then as life-forms, then biological chemicals, viruses today are thought of as being in a gray area between living and nonliving: they cannot replicate on their own but can do so in truly living cells and can also affect the behavior of their hosts profoundly. The categorization of viruses as nonliving during much of the modern era of biological science has had an unintended consequence. it has led most researchers to ignore viruses in the study of evolution. However, scientists are beginning to appreciate viruses as fundamental players in the history of life.

But viruses directly exchange genetic information with living organisms, that is, within the web of life itself. A possible surprise to most physicians, and perhaps to most evolutionary biologists as well, is that most known viruses are persistent and innocuous, not pathogenic. They take up residence in cells, where they may remain dormant for long periods or take advantage of the cells’ replication apparatus to reproduce at a slow and steady rate. These viruses have developed many clever ways to avoid detection by the host immune system, essentially every step in the immune process can be altered or controlled by various genes found in one virus or another.

Part of this comes from the ability of viruses to shuffle genes with as much deft as some genetic engineers. Viruses can pick up pieces of cellular genes or incorporate their genes into the cell’s genome. That means that evolution occurs all the time in viruses. It is a very dynamic process.

Are viruses alive? This is actually a really hard question to answer. Viruses are much simpler than other organisms that we definitely consider alive. Viruses must also use a host cell [and all its complex machinery] in order to replicate. This means that a virus cannot replicate without a host. Viruses are the ultimate freeloaders, they sneak into our cells, eat our food and rely on our homeostasis [their favourite temperature just happens to be body temperature!]

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