I read about such experiments some time ago. If I remember correctly, after being forced awake for some time, some people stopped being tired and had to be forced to sleep. I also believe there are individual differences, so while some people in the discussion describe their own interesting experience, keep in mind that others might react differently.

Identification of species and their relatedness has not.been done on morphological, but rather molecular basis for quite some time. In molecular terms, they are slightly modified grey wolfs. BTW, dogs are all one species, all very similar even on molecular level, and yet look at their morphology…