*yawn*...
see, i'm a good test subject because i avoid the sun most of the year. i can rule out vitamin d and light-sensitivity by pointing out i don't get much less sun in the winter.
these guys hibernate:
http://blogs.scientificamerican.com/brainwaves/2012/06/18/the-mysterious-brain-of-the-fat-tailed-dwarf-lemur-the-worlds-only-hibernating-primate/
...which suggests to me that hibernation is probably something our distant, pre-primate ancestors actually did do. further, we're more related to lemurs than might be obvious by looking at us side by side. we probably do have dormant "hibernation genes" that could be switched on in a lab.
did they get switched on at some point in the last ice age? and is it why vikings, siberians, natives and other descendants of northern ice age people get sleepy in the winter?
http://mentalfloss.com/article/30616/could-humans-hibernate
"For instance, a gene called PDK-4 becomes more active during squirrel hibernation, controlling their cardiac function and allowing them to sleep for extended periods. Most of these "hibernation genes" are highly conserved in species that don't hibernate - humans also possess the PDK-4 gene, for instance. Taken together, the evolutionary profiles of hibernation suggests that we humans may well still carry the genetic mechanisms needed to hibernate."
http://io9.com/5857754/your-hibernation-pod-is-ready
i was actually thinking of tarsiers, who (believe it or not) are our closest non-simian relatives:
