Equivalency states that some patterns which may influence other patterns dramatically may have recognisable equivalents in other universes – predominantly the Herewhere (U2), Elsewhere (U1) and the Neverwhere (U0).
Examples
Humanoids looking almost identical are known to exist across all three universes on some level – but they are not monophyletic and have subtle but striking genetic and physiological differences and can rapidly be identified based on their microbiota flora which are dramatically different (which can pose enormous risks to those who lack antibodies to certain diseases or conditions).
As a consequence, certain objects are statistically very likely to happen should humans exist long enough (fire, language, writing, architecture, engineering, sunglasses, chewing-gum, computers and pizza to name a few). These are however, consequences of human existence and are convergent developments and probably are not caused by memetic equivalency.
Persons with the same name are anticipated to exist, caused directly by memetic equivalency. While not identical twins, they are thought to be very similar in some ways and very different in others, though the first person of equivalency has not yet been met.