All bacteria and no wolves leads to over multiplication of sheep, mass starvation and population destruction. All wolves and no bacteria leads to intense predation pressure and population destruction. Nature has struck the perfect balance ensuring that the wolf's very strength carries with it its inherent weakness. Paradoxically it is the susceptibility to periodontal disease of the individual carnivore which confers a survival advantage on the species. No particular advantages would accrue to the flock which reduced its numbers dramatically at the onset of a drought.
Human omnivores appear to withstand a level of periodontal disease more readily than carnivores.
As a cooperative species even periodontal disease affected individuals could be of benefit to the survivability of the group. Conventional wisdom has it that the immune system is necessary to protect the host. This is a simple, linear 'cause and effect' concept that takes little account of degree or time within the holistic framework. The 'Cybernetic Hypothesis of Periodontal Disease' allows a range of options depending on degree and time. In a short time, and with minor challenge, the immune system will provide a minor degree of protection sufficient to protect the host genes and therefore the gene pool.