While studying the #evolution of the order of genes on #chromosomes, I computed numbers such as ”25 changes per megabase per million year”. To be closer to #standard units and use only one #metricsystem #prefix I considered changing it to “800 changes per base per #exasecond”, but it makes no sense because no genome has a length of 1 base and the Universe is younger than 1 exasecond. So maybe “800 attochanges per base per second”?