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Hank Green: Let me take you to a place where a race of wee people walked the Earth alongside pygmy elephants and dragons and giant tortoises.  They lived underground, made tools, and lived simple little lives, and they enjoyed smoking their pipes and gossiping about news in the Shire.  Okay, everything except that last part, I'm not talking about Frodo, in fact, I'm not even talking about fiction, I'm talking about actual humans who lived in Southeast Asia as recently as 13,000 years ago.  

Scientists nicknamed them 'hobbits', and their story is one of the most strange and amazing chapters in our evolutionary history, and it's also a good example of the remarkable diversity within the human family, the genus homo.  Officially, they're known as homo floresiensis, named after the Indonesian island of Flores, where their remains were discovered in 2003, and no anthropologist had ever seen anything like them.  Fully grown, they stood a mere one meter tall and weighed about 25kg, no bigger than a modern three year old.  Their brains were the size of grapefruits, by far the smallest of any known hominid, and yet, despite their tiny crania, hobbits lived on Flores for hundreds of thousands of years, stone tools, fire pits, and the remains of the animals they hunted, like dwarf elephants called stegadons, have been dated back more than 800,000 years.  

So, who the frick were they, and how did they get there?  At first, some scientists thought that hobbits were actually modern humans that suffered from microcephaly, a genetic disease that caused abnormally small skulls.  But hobbit skulls show few similarities with modern microcephalics, and it turns out that hobbits have a bunch of features that are way more primitive than modern humans, like their feet were flat like a chimp's, not arched like ours, and they had wrist-bones more like a gorilla's.  So another, and I think cooler, theory is that the hobbits actually descended from another human ancestor, homo erectus, who made it to Flores and then were subjected to a nifty evolutionary trick known as island dwarfism.  Since small islands have limited resources, natural selection favors those who need less of them, so animals that find themselves stranded in a place like Flores may become smaller over time.  In fact, that's what happened to the pygmy elephants that the hobbits hunted, they were just an island dwarf version of the stegadon.  It also helped that the hobbits' only predator was the Komodo dragon, a threat that didn't require being very big or like, a rocket scientist to deal with.  

What finally finished off the hobbits is another mystery, some experts think that there was a volcanic eruption, others suggest that the hobbits hunted their own prey to extinction, others say that they met their match in modern humans.  Our species first showed up in what is now Indonesia around 50,000 years ago, so it could well be that homo sapiens and hobbits met and maybe fought and maybe even other stuff that I don't really want to picture.  But this would at least explain the stories that indigenous people on Flores today still tell about wee, hairy, not very clever men who lived in caves.  Peter Jackson, if you're watching this, please take note, I would like to see this movie.

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