Viruses as Evolutionary Tools to
Monitor Population Dynamics
The field of virology is a discipline integral to the medical sciences. The affiliation of virology with population and conservation biology may not be as apparent. Viruses, and in particular virus evolution, may significantly contribute to the understanding of changes in host population structure. The impact of viruses is most notable when infection results in high mortality. Viruses can also exist as persistent or latent infections in a population. Although individual carriers in the population may experience few clinical effects, chronic carriers of a virus enhance the potential for epizootic or zoonotic disease in contact populations. In addition to their role in disease, viruses may also be sensitive genetic indicators of host population structure. In this chapter, we present topics at the interface of virology and population biology, beginning with an evident case where the virus is a pathogen to the host and concluding with a theoretical framework for the use of viral genes as markers of host populations. The focus of this discussion is on wildlife populations, with reference to humans where zoonotic potential exists.
To initiate an infection, a virus must first gain entry to the host by penetrating protective epithelial surfaces such as skin or mucosa. Viral replication can be restricted to these surfaces, or the virus can spread via the blood to other target organs in the body or via neuronal processes to the brain. Following systemic