Transcription
It is foreign to think about the variation in species within our very own genus Homo.
Sure, Neanderthals, Denisovans, and Homo erectus are all very different to us, but we often think of ourselves as being very similar. It is very human to think of ourselves above the laws of nature, above the natural processes of evolution. But today, we're going to be discussing a species that will perfectly broadcast evolution's impact on our genus.
On one island, in one country, surrounded by ocean, a species related to us was endemic. Isolated on the island of Flores, in what is now part of the Southeast Asian nation of Indonesia, lived a species of human rather drastically different to most of the others. This was Homo floresiensis, the Man of Flores, or Flores Man. Isolated on the island, away from other genuses of human evolution, was free to run wild on this species. And as a result, this was the smallest of all human species, standing at just marginally over one meter in height. Homo floresiensis has been lovingly dubbed the "real-life Hobbit" after the J.R.R. Tolkien book of the same name. This small species of human was quite unlike anything else in the human fossil record, with perhaps the exception of Homo luzonensis, whose evolution tells a similar story on the island of Luzon in the Philippines.
And today, we will be dissecting what we know about Homo floresiensis. We will be traveling back in time to the Indonesian island of Flores to discover what this strange being looked like, how it lived, how it evolved, and ultimately, how it became extinct. It is a case quite unlike any other, as we witness firsthand the process of evolution in action and how it affected some of our early cousins. Join us as we take a journey through the life of Homo floresiensis, or the "real-life Hobbit."
We're closer to Homo floresiensis than you might think. While it might sound like such a primitive-sounding human species would be lost to the annals of the Middle Pleistocene, it actually only went extinct around 50,000 years ago, having appeared on the scene around 190,000 years ago. It is a relatively short time for such a species to be around on planet Earth, almost a quarter of the time the Neanderthals roamed the icy northern regions throughout the infamous Ice Age. While we might be close to the species on a geological time scale, we still have much to learn about the actual physiology and structure of these small hominins.
Science has known about Homo floresiensis since September of 2003, when a team of joint Australian-Indonesian archaeologists took to Flores' Liang Bua cave with a view of researching the origins of human migration from Asia into Australia, assuming that the Indonesian Islands were used as stepping stones along the way. While the research was underway, one of the archaeologists in the team made a remarkable find: the bones of a human species which must have been just over a meter tall at best. The specimen was named LB1 after the cave it was found in, and multiple further skeletons were subsequently dug up throughout the next 12 months. Around 15 incomplete skeletons in total are known to science. Altogether, one of which was found with a partially preserved skull, giving us a good indication of Homo floresiensis' facial structure. The owner of this skull has since been dubbed the "Little Lady of Flores" and was estimated to be around 30 years of age when she died. Other fossil remains attributed to the species include teeth, arm and leg bones, feet, fingers, hips, and shoulders. The fossils were identified, described, and named by anthropologist Peter Brown in 2004, named Homo floresiensis after the island the primates called home.
The first thing that was noted about the species goes without saying: it was its diminutive size. Not only was Homo floresiensis physically small, it also had less cranial capacity when compared with Homo sapiens. That's not to say it was less intelligent. We'll go into it in more detail later, but advanced tool use and creation of fire has been associated with the species, indicating that it was a smart species indeed. You would have been able to tell our two species apart by looking at the facial regions alone. In fact, Homo floresiensis' teeth were comparatively larger than our teeth. They lacked a protruding chin like the ones possessed by us, and their noses were broader and flatter than ours. The little hominins of Flores were also more robust than we were. Their leg bones were comparatively thicker, and their feet were long and flat with short toes. As a result, Homo floresiensis individuals would have bent their knees further back than we do when walking, forcing them to have low locomotion speeds and an unusual gait, which would have seen them stepping high as opposed to traveling with their feet lowed to the ground. Their arm bones were also oriented differently to ours. Homo floresiensis' elbow joints were not as flexible as ours, and this forced them into an almost constant shrugging position with limited movement of the arm joints. The wrists of these hominins were also more akin to those of early Australopithecine hominins, the ones that first stepped down from the trees on two legs in the Middle Pleistocene. That's not to say that their bodies were less advanced than other human species. They had evolved to suit a specific role on their new island home, and each adaptation would have been a result of evolution to suit that new home.
A remarkable discovery indeed, but one that doesn't come without its own problems. At the time it was discovered, Homo floresiensis was unlike any other human species known to science. While the species was named as distinct from Homo sapiens in 2004, multiple theories soon arose that this was a mistake and that these little people of Flores were in fact members of the species Homo sapiens who suffered physical deformities as a result of birth defects. These theories have in turn been argued against, but we will explore them in this section.
The first condition to be proposed from Homo floresiensis skulls was microcephaly, a rare condition when at birth, a baby's head is smaller than expected. This is usually a result of the baby's head failing to develop during the pregnancy, but it can occur after birth if the infant's head stopped growing once it's born. This can also lead to mental development issues going forward in the child's life. This was the theory of American neurologist Jogan Weber, who compared the skull of LB1 with that of a human suffering from microcephaly, concluding that the Homo floresiensis specimen fell within the average size range of Homo sapiens with the condition. It's been a battle back and forth since then, with scientists arguing for and against Weber's theory. The majority of the scientific community do consider Homo floresiensis a separate species, however, and that the skulls are normal-sized for the species with no signs of impairment.
It was also argued in 2007, in a study of the Homo floresiensis bones, that the specimen may have been Homo sapiens suffering from Laron syndrome, a condition that may stem from interbreeding when a human is unable to make use of growth hormones, often causing a shorter stature and a smaller skull. This too is dubious, as no DNA samples have been taken to prove or disprove it. Also suggested, and all but disproved, were congenital iodine deficiency syndrome and Down syndrome, which are both known to cause impairments in physical and mental growth throughout an individual's life. In all cases, subsequent studies have shown that the Homo floresiensis bones in question do not show enough symptoms or characteristics of these conditions for the theories to be accurate.
So, we know what Homo floresiensis looked like and where it was found, but how did it evolve? How did a species descended from hominins almost the size of modern humans get so small in comparison? The answer can be found in its environment: islands. Island dwarfism, or insular dwarfism, is the evolutionary process which took hold in order to produce Homo floresiensis. But how does it work? Our little hominin cousins are actually a prime example. When Homo floresiensis' descendants first arrived in Flores, they were inadvertently trapped there. It is not known for certain exactly how their descendants arrived in Flores. Perhaps they floated over on debris carried by the ocean winds from mainland Asia. Perhaps they even swam island-hopping and bamboo rafts across various parts of Malaysia and Indonesia as they went. Alternatively, it could be that a temporary land bridge sprung up connecting Flores to the area Homo floresiensis' descendants were living, only to disappear and trap a population there.
Over the millennia, the descendants of Homo floresiensis began to change in correspondence to their new environment. On the mainland, a hominid could travel wherever he or she wanted with no natural barriers. Food was in abundance, and the world was theirs to explore. On an island surrounded by the ocean, however, these people became trapped. They could not, for one reason or another, manage to leave the island safely. An island is only so big, and food resources, if you cannot leave it, are limited. Natural selection therefore intervenes, and for those species that manage it, small sizes evolve. Being smaller generally means you don't require as much food to fuel your body, and in turn, that makes you better adapted to dealing with a limited environment. Plenty of modern examples of island dwarfism can be seen across the world. The island of Nosy Hara, off the coast of Madagascar, is full of creatures who are much smaller than their mainland Madagascar counterparts due to island dwarfism. Examples include the Nosy Hara dwarf lemur and the Nosy Hara dwarf chameleon, both of which are but a mere fraction of their usual sizes when found elsewhere. It even happened to the dinosaurs. Europasaurus, a genus of long-necked sauropod dinosaur related to the famous Brachiosaurus, became stranded on islands which are now parts of Lower Saxony in Germany. As a result, these creatures measured six meters long, relatively minute when you take into account that their mainland cousins were pushing 23 meters.
Conversely, island gigantism can also take place. Essentially, this is the reverse of what happened to Homo floresiensis. Instead of having large animals shrink, small animals grow large, often if there is an abundance of food available to them on that island that is not being exploited by a species which is already part of that ecosystem. Modern examples include Galapagos giant tortoises, the Philippine eagle, and the New Caledonian giant gecko. Whereas on the extinct roster, we have giant moas, sloth lemurs, and dodos.
Similar to other species of hominin that had spread themselves across the planet by the end of the Pleistocene, Homo floresiensis was no stranger to tools and technology. They were not of the standard of some of the later members of the Hominidae, such as sapiens and neanderthalensis, but they did the job that the diminutive island men required them to do: help them feed. Some of the tools harnessed by the early people of Flores include stone flakes and blades, perforation tools, and points. These tools date back to around 102,000 years ago and were likely used to slice and stab at small to medium-sized mammals that were hunted by Homo floresiensis. Furthermore, research that has been carried out on the polish and residue on some of the stone tools from Flores indicate that these people were using some of the blades and cutting devices to shape wood, which may have pointed to them being able to use spears or traps. These would have been basic, there's no doubt about that, but they would have been able to effectively wound the animals. Homo floresiensis preferred to hunt for the troop to close in with their spears and blades.
We also have concrete evidence that Homo floresiensis was able to use and control fire. Animal bones from the region indicate signs of burning, which seems as though they were cooked or at least held over a fire to make the meat more palatable. Like other early humans, it is within reason that Homo floresiensis perhaps knew how to at least transport fire or to make the most of it when hunting in the field. It wasn't just meat that these diminutive hominins were feeding on in the jungles of Flores, however. Evidence points to these early people cooking both meat and plant matter, and wear on the teeth of the collected specimens could be there as a result of the individuals chewing tough, fibrous plant matter. It is also sensible to speculate that as they traversed their island homes, they would have picked up a range of fruits to complement their potentially diverse diets. Still, despite the fact that this species came to be relatively late on in the Pleistocene, there is little reason to believe that they had harnessed a complex language. Lack of evidence points to these island dwellers having developed their vocal tracts to the point where they could hold a decent conversation. Instead, it is possible that they made a series of word-like sounds, including grunts, whoops, shouts, screams, and chitters.
Today, Flores is one of the Lesser Sunda Islands, located in southern Indonesia, and in the grand scheme of things, it isn't huge. It's about 15,000 square kilometers, an area, a very thin, snaking landmass. Being an island, the habitats vary. Volcanoes and mountains jut out from the center of the island, surrounded by tropical forests which reach the beaches. Amidst these forests were clearings and caves, many of which would have been utilized by Homo floresiensis as it wandered about its daily business. Sandy beaches, warm seas, and coral reefs surround the island, and the island is positively blooming with flowers and greenery. It sounds like a lush paradise, a perfect spot for an early hominin to find itself stranded for several hundred thousand years, and at first sight, it probably was.
Homo floresiensis were not alone on Flores, and due to the effects of island gigantism, they were not the tall predators. Our little cousins lived in the shadows of a deadly reptilian hunter that would have no doubt made a meal out of them given the chance: the infamous Komodo dragon. As the largest lizard in the world, this apex predator can reach around three meters in length in extreme circumstances and can easily pose a threat to even the most prepared members of our own species. It still lives on the islands surrounding Flores to this day, where it utilizes a rather grisly method of hunting, combining its sharp teeth with a venomous bite. All it takes for these huge monitor lizards to kill their prey is one snap. Hunting parties of dragons will, in modern times, hunt large hoofed animals and then simply wait for the venom and bleeding to take effect, patiently standing by while the victim suffers a grisly, untimely death. Conflict between Homo floresiensis and the Komodo dragons is certain to have taken place in the jungles and clearings of Flores, and unless the little hominids were lucky, it may not have ended well for them. Often, fortunately, the primates would have been able to climb, in dire circumstances, out of the reach of the venomous teeth and 70 kilograms worth of muscle.
Another less likely carnivore was also present on Flores at the time of the Flores Man. Sadly, it is now extinct, lost to the void of natural history, but in life, it was surely spectacular. Leptoptilus robustus was its name, a stork under the spell of island gigantism, the size of an adult Homo sapien at nearly two meters tall. Remains of this stork have been unearthed in the Liang Bua cave alongside specimens of Homo floresiensis. While one species hunted the other, they were certainly close neighbors. As a member of the Leptoptilus genus, this stork has three extant relatives: Africa's Marabou stork and Asia's lesser and greater adjutants. Scientists have been able to infer that due to the close proximity to these living birds in the stork family tree, that the giant stork of Flores likely looked very similar, only bigger and probably meaner too. Although its modern cousins are mainly carrion feeders, they are known to take live prey. Fish, insects, amphibians, baby crocodiles, and even flamingos are readily taken by these odd-looking avians. A handful of scientists have theorized that the giant Flores stork may have been capable of taking Homo floresiensis individuals, potentially young or sick members of the troop. If so, it was a dangerous world for these pint-sized primates.
Island gigantism also extended to some of the much more unlikely residents of Flores: rats, much larger than the brown or black rats that can be found in the Northern Hemisphere. These rodents, over half a meter in length, still exist on the island today. It's not just giant rats that would have shared the forests with Homo floresiensis, however. A colorful array of birds, reptiles, amphibians, and insects would have fluttered, leapt, and buzzed through the undergrowth, some of which were likely picked off by the hominins as easy meals. Today, the island is still very much a naturalist's wonderland, rife with the luminous plumages of flowerpeckers, hanging parrots, sunbirds, pittas, and hornbills.
Perhaps the strangest creature to share the forest with Homo floresiensis was what our little cousins actually ended up hunting. Several species of the genus Stegodon, an animal very closely related to elephants that in other parts of the world were growing to some of the largest mammals of their time. However, this is a tropical island, and nothing is what it seems when it comes to evolution and prehistory. The Stegodon species on Flores were comparative dwarves to their continental species. In fact, they would have probably only grown up to your shoulder, and that's an upper estimate. Some of these species were more akin to the sizes of donkeys and goats than elephants. In yet another strikingly bizarre occurrence of island evolution, it was in fact Stegodon bones that were found in Liang Bua cave with evidence of burn marks, implying that these little proboscideans were being hunted, butchered, cooked, and eaten by the dwarf hominins of Flores. This was a world where dragons and giant birds ate people who in turn ate elephants.
As you have most likely realized, there are no other species of human being alive on planet Earth today. Homo sapiens is the only one to remain, and Homo floresiensis is unfortunately a thing of the past. But why? Surely, secluded on our little island paradise, these primates could have thrived away from the turmoil and chaos of the mainland. As with all things in nature, it isn't that simple. Two main theories are running as to why Homo floresiensis disappeared from the jungles of Indonesia, and as it usually happens, Homo sapiens interference is listed as one of them.
Theories have been considered which note the fact that Homo floresiensis disappeared just as Homo sapiens arrived in Flores. Perhaps when the two species met, the island dwellers did not welcome the intrusion. Alternatively, perhaps the early humans didn't recognize Homo floresiensis as humans, wiping them out so they could live on Flores. Of course, it needn't have been violent at all. It might have just been a case of tough competition. As sapiens moved in, perhaps floresiensis just couldn't keep up. Humans, as we know, are destructive, and being larger required more food than the original inhabitants of Flores. As the humans hunted the Stegodon relied upon by the island dwellers, maybe they couldn't cope with the loss of food and died out as a result.
Alternatively, there is a chance that the little hominins were victims of their own environment. Flores is a volcanic island with one main active volcano, Kelimutu. Evidence of volcanic eruptions show that the mountain could have choked the island in the Pleistocene, wiping out the large inhabitants of Flores, either directly or indirectly through wiping out food sources. Either way, the little people of Flores are lost to time, and all we have is their bones.
The world over, a myriad of myths abound regarding stories of wild man or apeman who secretly hide themselves in the forested regions of the world. Often, prehistoric species are blamed or attributed to these stories, often with little concrete evidence, but the stories are interesting to say the least. Homo floresiensis is no different. However, as you can imagine, though they aren't going to be the subject of a Bigfoot-like story, nor are they the explanation for the Yeti of the Himalayas. No, Homo floresiensis has been looped into Indonesian folklore in the myth of the Abu Gogo. Yeah, the people of Flores have long spoken of little human-like creatures that scamper around the island's jungles. They have named these creatures the Abu Gogo, "Abu" translating to grandparent, and "Gogo" translating to "one who eats anything" in the native Nage language of the central region of Flores. Stories originating from the island, presumably passed down over generations, describe the Abu Gogo as quick-moving humanoids just over a meter in height. Their faces and noses are broad and flat, their bodies are hairy, and they are allegedly capable of producing whisper-like chattering noises, repeating what is said to them in parrot fashion. Sounds familiar, doesn't it?
One of the most well-known stories concerning the Abu Gogo describes how villagers in the 18th century grew tired of the creatures stealing from their sediments and attacking their children. When they could take no more, it was time to hatch a plan. In a Southeast Asian spin on the story of the Trojan Horse, the villagers showered the Abu Gogo with gifts in order to convince them to stop the rains, specifically palm fiber, which could help the little humanoids craft clothes. Only there was a sinister catch. As soon as the Abu Gogo carried the palm fiber off into the cave, the villagers tossed in a firebrand after them, igniting the easily flammable gifts and the creatures carrying them. The story goes that almost all of the Abu Gogo were killed in the retaliative attack, but one pair managed to escape the blaze, and the Abu Gogo are rumored to reside deep within the forests of Flores to this day.
It's an elaborate and entertaining tale, but how much of it is true? The stories of the Abu Gogo pre-date the discovery of Homo floresiensis, for starters. These tales supposedly span generations, whereas science has only known about the existence of Homo floresiensis for 20 years. So, it was then that when ethnologist Gregory Forth suggested in 2008 that there may be a hint of truth in the Abu Gogo legends and that the stories actually describe ancient encounters between our own species and Homo floresiensis, the cryptozoology community went wild. A quick search of the species will lead you to its connections to folklore before too long, but could that really be true? Were there truly surviving populations of this small hominin roaming around the forests of Flores in the 18th century, stealing food and human children from villages? Most scientists don't seem to think so. The lack of bones younger than 50,000 years old is what sways it. There's just simply no way that such a notable species could go unnoticed on a densely populated island for so many years without scientific record or detection. For now, it looks as though the Abu Gogo will remain a myth until we've got scientific proof of an extinct hominin from the late Pleistocene creeping through the jungles of Flores.
Homo floresiensis can also consider itself a pop culture reference. "Hobbit" is actually the most common nickname for these hominins, based on the fictional race of short humanoids in the book by the same name. When the bones were dug up, some of its discoverers actually suggested calling the creature Homo habilis. So there you have it: an island stranger than fiction, lost to time. A world where our ancient cousins fled from the largest extant lizards in the world. A world where said ancient cousins hunted elephants the size of donkeys. A world where it was a common sight to wander down to the lakeside to drink, only to be met face to face with a stork taller than a man. Islands provide evolution with a blank canvas to run riot over, and the results often cough up some of the most remarkable ecosystems on Earth. So the next time you sit down to watch your favorite fantasy epic, spare a thought for your long-lost cousins, the tiny island-dwelling Homo floresiensis of ancient Indonesia.