Disease epidemics can be devastating. How can the spread of infectious disease be controlled? It is believed that more genetically diverse host populations have lower prevalence of infectious diseases. This pattern is particularly strong in agricultural systems where diverse mixtures of crops are less susceptible to epidemics than single species (the “monoculture effect”). But how does host genetic diversity affect disease spread? IU professor Curtis M. Lively uses theoretical modelling as an approach to investigate this question in the March 2016 issue of The American Naturalist.
Infection-genetics models: This study examines two theoretical models of infection genetics, namely the matching alleles model (MAM) and the inverse matching alleles model (IMAM), to ask whether the effect of increasing genetic variation on disease spread can be affected by which model underlies the genetic process of infection. Infection genetics models are broad, theoretical frameworks used to describe the interactions between specific host genotypes and parasite genotypes. Genotype is the genetic make-up of an individual. Alleles are the alternative versions of the same gene. For example, an individual with genotype AB is defined by the presence of allele A at one gene and B at another gene while genotype ab is defined by the presence of different alleles at the same genes, a and b. (more…)