Curious Parallels ~ Memetic vs Genetic Pandemics

There are curious parallels between the geographic spread of non-rational ideas and biological parasitism -- or phrased differently -- between memetic and genetic pandemics. Consider two examples from European history -- the expansion of Christianity and the spread of the Great Plague (a.k.a. the Black Death) -- as shown in these two maps... Different timescales, points of origin, and mechanisms for transmission + replication + mutation, of course, but nevertheless parallel phenomena for humanity to apply scientific methods on, to ever more thoroughly understand, and to ultimately prevail over.