Humans like to think of themselves as self-determined individuals who make their own decisions about their fate. Even when humans lose control over their minds, in anesthesia or under the influence of hallucinogenic or psychotic drugs, they think of it as a consequence of their own choosing.
But the idea of human self-determination grossly overstates the scientific data. Overwhelmingly, each of us is the subject of competing influences.
Of course, as Jean-Paul Sartre, a famous existentialist, once stated: "You can always make something out of what you are made into." Just don't be overly optimistic about the extent to which you are the master of your destiny.
The competing forces that, every second of your life, pull you in one direction or another, are multiple: your genes and your upbringing, the zeitgeist and your peers, and the condition of the biosphere in your environment.
But wait a moment! We are not yet done curtailing your freedom of choice.
Because there is not just one human biosphere—the external one. Each of us is also a biosphere in our own right.
Each of us is host to a greater number of viruses and bacteria than there are humans walking planet Earth.
And it's not that our symbiotic bacteria are in our guts just to help us digest our food. They are there for their own agenda.
Sure, there are also fungi, protozoa, and other organisms commonly called parasites. But let's just focus on viruses first.
Viruses have a very fast evolutionary pace indeed. They can go through many generations in a matter of hours. They multiply rapidly. Viruses go viral, so to speak.
And they adapt to us, their hosts, faster than we adapt to them.
It is generally not in the interest of viruses to kill their hosts. Lethality is probably just a stage in their evolution.
Do we adapt to viruses, or do viruses adapt to us? The fact is that old viruses (those that have been around us for a long time), like herpesviruses, often don't kill, and can accommodate themselves in a human host for decades.
Newer viruses, like HIV, are often more virulent.
Viruses optimize to exist in the largest possible number, and for as long as possible.
For this purpose, viruses modify a large range of behaviors in their hosts.
It's no coincidence that rabies-infected dogs salivate excessively and bite randomly. These are symptoms and behaviors induced by the virus to give it an avenue to propagate.
And when we sneeze while carrying an influenza virus, it is not just a random reflex; it is a series of physiological modifications induced by the virus to facilitate its spread.
And how about herpesviruses that spread by genital contact? Such viruses have a vital interest in a host's sexual promiscuity, even into old age.
So, could a herpes strain be a good cure for low libido and erectile dysfunction?
You can bet on it. And it won't stop there.
Humans will farm viruses as treatments for all kinds of maladies, and if there ever are medications that expand the human life span to hundreds of years, viruses and viral vectors will have a crucial role to play.
