Hey there every peoples!
If you do any kind of search for information on evolution you eventually come across the raging debate surrounding our own origins. Never mind the countless myths and stories cultures have created to explain it (or the one fundies constantly try to foist on everyone else), science has plenty to debate on its own. The evolution of humans is probably one of the most difficult subjects to track in modern science. It seems that almost every bone we manage to tease out of the earth causes us to rewrite the history of early man. One anthropologist characterized the rapidly changing face of human evolution best when she said “I never give the same lecture twice”. And once in a great while a find comes along that so profoundly shakes our family tree that scientists all but draw lines in the sand. Enter “The Hobbit”.
In 2004, a team of paleoanthropologists began excavating in Liang Bua cave on the small Indonesian island of Flores. They were searching for the remains of Homo erectus, an early human ancestor known from other islands in the region. As the team dug through the layers of sediment they found the bones of giants rats, komodo dragons, and dwarf stegodons (ancient relatives of elephants). They also found many stone tools such as awls and scrappers, signs they were looking in the right place. Eventually they came across the skeleton of a small female. Due to the damp conditions it was preserved in, the skeleton had to spend a day drying. Afterwards, when the scientists were able to examine the specimen in better detail, they could not have imagined what they found.
Liang Bua cave, where remains of "The Hobbit" were uncovered. image from Wikipedia
The skeleton was not from a child as originally thought. At a mere 3 feet tall, they scientists had discovered a tiny human who bore a suite of primitive characteristics, including a brain no bigger than a chimpanzee’s. The scientists named her as a new species: Homo floresiensis. As to be expected this set off a firestorm in the press and the scientific community. Critics were quick to try and find an alternative explanation. Some dubbed the specimen as a diseased or malformed child while the tools were created by normal modern humans. Others labeled it as a pygmy modern human, which are known from the Congo. Indeed, an adult human the size of a six year old with a small brain capable of making complex tools was very hard to swallow. The debate only got more intense when remains from seven more individuals, including a complete second jawbone, were found. Could the whole population have been diseased? The controversy grew further still when the remains were dated: the stone tools associated with the diminutive humans were dated to 95,000 years ago; much more provocatively, the bones of the small woman were dated to just 18,000 years ago. Considering modern humans are thought to have reached the region by 45,000 years ago. The skeleton, nicknamed “The Hobbit” for her likeness to J.R.R Tolken’s race of hairy footed midgets, produced 2 of the most profound implications for humankind imaginable: not only was Homo capable of such diminutive size, but also that we shared the planet with another species of human so recently.
Skeleton of LB1, dubbed "The Hobbit". Image from Anthropology.net
“The Hobbit” is believed to be an example of what is known as the “island rule”. This concept states that when stranded on an island, some animals tend to shrink as a result of limited space and resources. The rule also states that other animals, with a lack of competitors or predators, will grow larger. This was already seen in the animals found alongside “the Hobbit”: on the mainland, Stegodons were the size of modern elephants, but within the confines of the small island of Flores, had shrunk to the size of a cow. An ancestral monitor species arrived in Indonesia and finding no large mammalian predators to compete with grew into the iconic Komodo dragon (same with the giant rats on Flores). This phenomenon is found throughout the world: giant bunnies in the Mediterranean, flightless birds in the Indian Ocean, and even dwarf mammoths off the coast of California (more on that in a future post). But we have always thought that we were above the rule. We thought we were far too clever and inventive to play by nature’s rules any more. If we found ourselves in a new environment, we came up with new technology to cope. Homo floresiensis suggested that even the mighty Homo had to evolve to fit its new world. As you can imagine, this notion only dumped gas on the firestorm of debate surrounding “The Hobbit” and her implications for human evolution.
The chief criticism was that “The Hobbit” was a diseased child suffering a condition called microcephale. Microcephale causes the afflicted person to have stunted growth, resulting in a small stature and more specifically a shrunken head. Since microcephale is hereditary it was contended that this could account for the other individuals. But scans of “The Hobbit’s” skull challenged this interpretation. The scan revealed a brain not like modern humans. Not only was it small, but it possessed many primitive features found in earlier human species. Also the frontal and temporal lobes were very different than those of microcephalic modern humans. The brain scan also showed that Homo floresiensis was not a pygmy since pygmies have full sized brains despite their small stature. Finally analysis of “The Hobbit’s” wrist bones also showed primitive features associated with earlier human species like Australopithecines. Homo floresiensis, it seems, was able to stand up to everything thrown at it.
Skull of Homo floresiensis compared with a microcephalic modern human. Image from Wikipedia
But if Homo floresiensis wasn’t a modern human, what was it? It was originally thought to be a descendant of Homo erectus, a well known human species thought to have reached this part of the world around 1 million years ago. Since Flores was an island even back then, it has been suggested that Homo erectus may have had some kind of primitive water craft. While experimental archaeology has shown that such a craft could be built with H. erectus technology, the idea is still controversial. “The Hobbit’s” primitive features throw a wrench into this idea. They suggest an ancestor older than erectus. Homo erectus was long thought to be the first human out of Africa. Scientists thought that everything before, even the tool making Homo habilis, were too primitive to have made the journey. This idea was shattered in 2002 when fossils at the site of Dmanisi in the Republic of Georgia turned up a species much more primitive than erectus. Originally classified as a subspecies of erectus, the creature has since been given its own species, homo georgicus. Could this creature have been the ancestor of “The Hobbit”? Only future research will tell.
Controversy continues to swirl around Homo floresiensis. Thought to have died out 13,000 years ago (possibly due to a volcanic eruption), some think “The Hobbit” may have survived into historic times. The natives of the island have stories of a creature called “Ebu Gogo” who sounds eerily similar to Homo floresiensis. According to island lore, a race of miniature human-like creatures with poor language who lived in caves. The villagers would leave out plate of food for the creatures, who would eat everything, even the plates which are made from dried pumpkins. In fact “Ebu Gogo” means “grandmother who eats anything”. One tale even tells of “Ebu Gogo” snatching a girl and taking her back to their cave and consuming her. This enraged the villigers who killed all the creatures in the cave in vengeance. Is this story based on an actual event or is it little more than tribal folklore? We may never know.
Reconstruction of Homo floresiensis with a giant rat. Image from National Geographic
Despite all the controversy “The Hobbit” continues to fire the imagination. Scientists are now combing other regions of the island in the hopes of uncovering more about this most fascinating and enigmatic branch of our family tree. And speculation has even emerged that there could be other species of dwarf humans waiting to be discovered on other islands. But “The Hobbit” has a very important lesson to teach. She teaches us that humans are not above nature. We are a part of nature. We respond to nature just as nature responds to us. I think Homo floresiensis is one of the most powerful symbols of our connection to nature. She reminds us that humans adapt to nature like any other creature we share this planet with. I hope the scientists succeed in their search and are able to tell us more about “The Hobbit”, perhaps the greatest surprise and wonder the evolution of humans will ever produce.
Till next time!