They say these guys have existed since the beginning of life on Earth. As far back as there's a plant or animal record, there are viruses. Life has adapted, changed, grown... and still the virus plagues it. It has been re-inventing itself over and over again in order to outwit, outlast and outplay its victims. They started as humble messengers, genetic strands that carried hereditary information from newly developed life to its offspring. As life transformed and become more complex, viruses lost their primary function when cells took over their role.
But the virus didn't take so well to being fired, and like any disgruntled ex-employee, began a millennia-spanning march to destroy that which it no longer served. They became unstoppable parasites, infecting rather than exchanging genes with their hosts; proscribing each cell with their own genetic formula. They developed the ability to jump from species to species by changing their genetic material to fit the host they infected.
The virus of today is highly complex and nearly impossible to control or contain. Over the past million+ years, they've developed a level of survivalism and efficiency that is astounding to behold... even to comprehend... even as we suffer from their success, its impossible not to admire them. We keep studying, keep trying to find new ways to defeat them, and they continue to calmly mutate around every new thing we throw at them.
Alive or dead? So far there has been no known form of life on Earth that is not susceptible to deadly viruses. They are small enough to hide between light waves, too small to be seen by anything but an electron microscope. It can lie dormant for long periods of time, indefinitely in some cases. It is not technically a life form, but you can ask the question: is the virus the most successful organism in the history of our planet?
We have been struggling with the deadliest, worst viruses since the beginning of humanity itself. Whether you've suffered from the common cold
or something more rare and gut wrenching, you've definitely come into contact with a human virus. The names of viruses on this list should strike fear into your very heart. Just thank the starts that you've never caught on of these dangerous, deadly strains.
(PS. Before you head to the comments section in a huff, the Black Death was not a virus, it was bacterial.)