Some animals, like groundhogs, bats or bumblebee queens, skip the season altogether by hibernating. They nestle down in the fall and get ready for a season of inactivity by dropping their body temperature, metabolism, and breathing and heart rates. This allows them to conserve energy—their body fat, as long as they have enough of it, provides them the energy to survive until spring.
So it intrigued me to learn about hibernating humans. Humans! They were a different species from us Homo sapiens (Neanderthals? Homo heidelbergensis? That part’s still being worked out), and they lived over 400 thousand years ago in northern Spain.
The fossilized bones of these ancient humans show patterns similar to those on bones of other hibernating animals. (Like those of the cave bear they found close by!) It appears that bone growth was interrupted each year while these early humans slept the winter away in caves. The fossils also indicate that they were hard-hit by diseases common to hibernating animals, such as kidney disease and bone deformations.
But it’s always been assumed that humans CAN’T hibernate. We’re too big, we need too much food, and we evolved in hot climates that wouldn’t require us to sleep for months at a time. And unlike hibernators, our bodies tend to stop working if they get too cold or stay still for months. And really, why would we bother? Humans have enjoyed fire and hunted large game for millions of years, so we don’t really need to hibernate, especially in an area as gorgeous as Spain. Right?
|The hibernating fat-tailed dwarf lemur shares 98% of our human genes. Its fat tail provides energy while it’s zonked out.|
All of this makes me appreciate how fascinating hibernation really is, was, and could be. But also, I’m now feeling awfully grateful that we don’t need to do it ourselves!