[notahacker]

Specifying that as something isn't directly testable, it's better that a bold new theory should actually be the null hypothesis isn't how science works! We've observed a lot of populations with little or no natural light and there is no reason to cherry pick the one or two which actually conform to Ekirch's proposed "standard" form of sleep. I mean, for a start, assuming "pre industrial revolution photoperiods" generally matched the ones in Wehr's study involves pretending that seasons don't exist in most of the places Ekirch's soured material came from!