Fig. 2

Red Queen dynamics. a Oscillation of eight host genotypes in a sexual population of hosts. b Oscillation of eight parasite genotypes; infection requires that the parasite genotype “matches” the host genotype. c One host genotype, and its matching (infective) parasite genotype. Note that the parasite genotype is about 90 degrees out of phase with the host. Also note that the amplitude of the oscillation is much higher in the parasites population than in the host population. The results were generated using a computer simulation (Lively 2009)