Virus or parasite?

It is often remarked that humans differ ecologically from other animals by virtue of the fact that they exploit, destroy and consume their environmental resources, rather than establishing a state of sustainable equilibrium with their environment. In this respect, humans have been compared, perjoratively, with viruses. Viruses invade other cells, consume the resources of those host cells, (their temporary homes), in order to reproduce, and then destroy those host cells and expand outwards to find other cells which they might invade and exploit. The planet Earth is comparable to the host cell of a viral colony. If human technology destroys the living habitat upon the Earth through some combination of, say, global warming or nuclear war, then humans may conclude that their only chances of survival are to leave the Earth and to colonise other planets in the galaxy. If this comes to pass, then humanity would, indeed, be a super-virus.

There is, however, an alternative type of micro-organism which humanity might decide to mimic: the symbiotic parasite. These are micro-organisms which invade other host cells, but rather than destroying those cells, they evolve with the host DNA to establish a mutual dependency. Perhaps the best-known example of this is the mitochondria in our own eucaryotic cells, which were formerly independent aerobic bacteria, but which have invaded our cells, and, by virtue of performing the function of converting oxygen and sugar molecules into useful work, have become entwined with the structure and function of our own eucaryotic cells. They are parasites, but symbiotic parasites. If humans develop into a state of mutually dependent, sustainable equilibrium, (sustainable at least on the time-scales of stellar evolution), with planet Earth, and begin to play a positive role in the various feedback mechanisms which maintain the atmospheric and biotic equilibrium of the Earth, then humans would function as symbiotic parasites.

The question, then, is this: does humanity want to be a super-virus or a super-symbiotic-parasite?