In the video below, Gershom Zajicek M.D speaks about certain viruses as necessary (obligate) symbionts; meaning we were once infected with a virus that is now in an inseparable relationship with us. The common idea is that viruses are infections, but he argues that they span the spectrum of relationships from destructive, to beneficial and in some cases, necessary for our survival.
Some of these vital viral strings, embedded in our genome provide services such as helping forge the relationship between the uterus and the early stage embryo, the formation of the placenta and so on. Because they offer adaptive advantage they have formed an obligate relationship over time and this is how they get to ride on the wave of relationships we currently call human. One example of the fruits of this relationship is the proto-oncogene which governs cell division. It helps our cells grow and divide in specific and limited ways to form and maintain such things as cells and tissues. In fact, when this process is broken we see cancer.
Among the things Dr. Zajicek proposes is that transposable elements (TEs) and Human Endogenous Retro Viruses (HERVs) are two names for the same phenomenon. Transposable elements are snippets of DNA coding that can communicate one cell to another, or across organisms or species, and changes the way an organism operates. This means they can actively modify biological functions during the lifetime of an organism. This method of evolution may need to be added to the currently understood mechanisms which include , descent, genetic variation, mutation, genetic drift, natural selection, and coevolution.
If HERV’s and TE’s are synonymous, this would have enormous implications not only to evolution, but to many other disciplines such as medicine, ecology and so on. TE’s, for instance, may be in some cases an immune response from one creature to defend against what it perceives to be a pathogen (from its perspective). We would receive this as a disease. There may be vectors, such as bacteria that mediate this process. If we look through this lens, we see the dynamic root of many of our own diseases in the way we relate in the context of the larger biological body of which we are part, and on which we depend for nourishment.
Of course, whether this vision is an ghost due to the lens or a clear image of what is really going on remains to be seen. If we expand the notion Dr. Zajicek proposes on to the larger biological relationship landscape, this would indicate there is an active dynamic and far less than random communication flow by way of meaningful structures, not only within species, but between them. It would mean that species may not be the level at which we should define organisms, but by relationship spanning from antagonistic to obligate. (Necessary). If we were to apply a ven diagram to the biological landscape, we would see many overlaps that violate what we have traditionally considered species. In other words, defining organisms by genetics alone may have blinded us to how the larger, more revealing biological relationship landscape works.
While we have a long way to go to unravel this Gordian knot we call biology, if this proves true, it would explain quite a bit, have enormous predictive capacity, and if applied properly would have a huge impact on our understanding of evolution on many levels beyond the scope of Mendelian (inherited) genetics.