According to Emma Kowal of Harvard University, yawning evolved in our hunter-gatherer ancestors to be a highly efficient method of bug-consumption. Her argument is thoroughly and impressively researched, logically presented, undeniably captivating, and hilariously wrong.
Kowal's presentation on yawning as a means of "high throughput entomophagy" (i.e. large-scale bug eating) was awarded second place at the East Coast version of last year's Festival of Bad Ad Hoc Hypotheses (aka BAHFest!). Her presentation was inspired, to say the least:
Inspired by a comic by SMBC's Zach Weiner, BAHFest is "a celebration of well-researched, logically explained, and clearly wrong evolutionary theories." Winners are awarded a sculpture of Darwin shrugging skeptically.
Last year's was the second annual BAHFest. Two more festivals are scheduled for 2015 – one for the East Coast and one for the West. Watch the winning presentation from 2013 – in which MIT researcher Tomer Ullman argues that humanity's early ancestors harnessed the "natural adrenaline boost" brought on by the sound of wailing babies by wearing them into battle – here.