Making sense of the Flores find
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In August 2003, in the Indonesian archipelago, a dig on Flores had plumbed six metres in a limestone cave called Liang Bua, and an extraordinary find was coming to light. "You could tell something was going on," says one of the research team. "There was no eureka moment, but a hush fell over the cave, and people started looking stressed. When they asked for a box, it was a real indication of importance" - they had found something they wanted to remove in one lump of sediment, so they could look at it more carefully later, away from the dig.
This something took three days to extricate. It was a skeleton, so tantalisingly conserved that some of its sections were still joined, and so fragile that it had the consistency of wet blotting paper. The researchers thought it was a pre-modern child; they took it to the hotel where they'd set up a bone room and began to study it.
Between that sticky tropical day and late spring the following year, they measured bones, dated dirt, compared data and literature and artefacts, consulted colleagues, and tried to piece together the how and why of whoever they'd found. Rumours began to circulate: something big had been found in Indonesia, but no one was at liberty to say what.
On 28 October 2004, Mike Morwood and Peter Brown - both then from the University of New England - led a group of Australian and Indonesian collaborators into print. Their findings, published in Nature, announced the discovery of a tiny human, just 1.06 metres tall and with a strange mix of ancient and modern characteristics. Her face and most of her teeth would have looked similar to ours. But her pelvis and jaw resembled those of Lucy, that famous 3.2-million-year-old australopithecine, or pre-human species, found in Ethiopia in 1974. Her skull was tiny, which meant her brain had been too. Extraordinarily, she had died only 18,000 years ago. Her ancestors, prehistoric as they seemed, had existed at the same time as ours; that is, until very recently.
"I'd thought the skeleton would be too old for the range of radiocarbon dating," says Mike Morwood, now at the University of Wollongong. "And the results came back as 18,000!" He laughs. "Peter Brown said, ‘Well, this is going to delay the paper; it's obviously wrong.' Obviously wrong ..." Kira Westaway, a PhD student present at the dig now working at Macquarie University, designed some of the dating methods used to analyse sediment from around the skeleton and other parts of the cave, as well as to verify that 18,000 years. As Westaway remembers it, the usually abstinent Morwood took in the date and walked quietly from the lab, saying, "I'm going to need a drink to think about this."
There was discussion about the smallness of the body and brain, for which the team ruled out several possible causes, including "primordial microcephalic dwarfism". There was discussion, too, about her ancestors, and how she came to be on the island; it was suggested that her stature led back to "the first hominin immigrants [who] may have had a similar body size to H. erectus and early Homo, with subsequent dwarfing" - as was known to occur in populations of other creatures trapped on islands - "or an unknown small-bodied and small-brained hominin [who] may have arrived on Flores". And there was discussion about whether she belonged with us Homo sapiens; Brown initially thought not, but, taking morphology and phylogeny into account, decided she was "best placed in this genus". What was more, she was believed to be the first example of a whole new species of human. The Nature paper designated her Homo floresiensis.
In the search for a name less cumbersome, the skeleton was called Flo by some and the "little lady of Flores" by others. But it was her nickname that sealed her stardom. Short of stature, and found in a very deep hole, she was given the media-friendly tag of hobbit.
The first person I read on the hobbit was Tim Flannery, writing in the Bulletin the next week, telling the story through his understanding of Flores, its stegadons (extinct mini-elephants) and komodo dragons (extant uber-lizards). He discussed island dwarfing, that tendency for some species to shrink under selection when trapped on an island. But most memorably, he raised something that had always puzzled him about lice. Genetic studies of lice indicate that humans "host two species which split more than a million years ago". One has been with us all this time, while the other "appears to have jumped onto human heads about 30,000 years ago". Perhaps, Flannery suggested, the second louse reached us around "the time of first contact between us and the hobbit". "I tend to approach these stories in a biological context," he says now, "to see if they make sense in the context of what we see in nature. The lice were just an example of that."
In the wake of the Nature paper, all sorts of scientists began considering the hobbit through the lens of their own lice equivalents: specialists in the fields of pre-human and human anatomy, ancient and modern pathology, paleoanthropology, or the environmental drivers of physical evolution, brought their own approaches to bear. Maciej Henneberg, from the University of Adelaide, read the paper alongside another, about a 4000-year-old skull from Crete, whose owner had suffered from microcephaly, an abnormally small head. In an ABC Radio interview the day the Nature paper was released, and in a subsequent opinion piece for Adelaide's Sunday Mail, Henneberg attributed the "peculiar appearance of the skeleton" to that "well-known pathological condition". He expected to maintain this position, he said, "until more skeletons of this new species are discovered". "I simply read the paper, did some statistical analysis and comparison with this other pathological specimen, and announced my views as I honestly held them," he says, almost four years on. "And I thought, That's the end of the story."
It was just the beginning. A series of papers endorsed the Flores skeleton - or LB1, as she was more prosaically known to scientists - as a new species. Dean Falk, from Florida State University, worked on LB1's controversially small brain. As far as science knew, a brain capable of the behaviour attributed to hobbits, like toolmaking and hunting, had to be much bigger than the hobbit's 417 cm3. Our brains, by comparison, are around 1450 cm3. But Falk's endocasts of LB1, moulded from the impression the brain makes inside the skull, appeared "consistent with capabilities for higher cognitive processing". Brodmann's area 10, involved in "processes such as the undertaking of initiatives and the planning of future activities", was particularly prominent.
The original team, including Morwood and Brown, revealed that other bones from the Liang Bua cave - similar to those of the hobbit - covered dates from 95,000 to 12,000 years ago, in the Pleistocene era, while the modern bones found all dated to the more recent Holocene era, which spans the past 10,000 years. Taking this to "further demonstrate that LB1 is not just an aberrant or pathological individual", they suggested that H. floresiensis might not have evolved from that earlier hominin, H. erectus, but from an even earlier ancestor like Lucy.
A collaboration between universities in Australia, Indonesia and the Netherlands found similarities between tools excavated earlier on Flores by Morwood - between 840,000 and 700,000 years old - and those from Liang Bua. Perhaps, they suggested, H. floresiensis had been making these tools all this time. A PhD student, Debbie Argue, realised that she could compare LB1's measurements with her own database on Pleistocene hominins, plus some additional microcephalic humans, a "pygmoid" excavated elsewhere on Flores, and various H. sapiens, including pygmies from the Andaman Islands. She concluded that "LB1 is not a microcephalic human, and it cannot be attributed to any known species. Its attribution to a new species ... is supported."
Dean Falk went back to the brain and concluded that "despite LB1's having brain-shape features that sort it with normal humans rather than microcephalics, other shape features and its small brain size are consistent with its assignment to a separate species." Work on one of the hobbit's shoulders indicated that this joint resembled earlier H. erectus, not H. sapiens, anatomy - further confirming its novel status - while investigation continued into its long, flat feet and extensive collection of tools.
And at the Smithsonian Institute, Matt Tocheri, a PhD student who'd been captivated by the find since its announcement, met Lorraine Cornish, a conservator from London's Natural History Museum, and saw casts that Cornish had made of LB1's wrists. "Whether or not the hobbits were pathological humans or another hominin species, I would have predicted they'd have the same wrist as us," he says. "Australopithecines have a wrist more like chimpanzees, whereas modern humans and Neanderthals have a structurally modified wrist. I expected the hobbit's wrist to look like that of a modern human or Neanderthal, rather than that of an australopithecine."
Instead, one of the bones, the trapezoid, looked "just like the trapezoid you'd see in a chimpanzee, a gorilla, or an orangutan". Which meant that "it was sharing a primitive morphology that disappeared from our lineage at least 800,000 years ago." The "clear implication" of Tocheri's work, said New Scientist in September 2007, was that this "tiny human-like creature ... really was a distinct species". Here, said Tocheri at the time, was "the smoking gun" the hobbit's case had needed.
But against all this stood those who questioned the original work, sometimes thinking - as Henneberg had - that it was just a pathological modern human. Immediately after the Nature paper was published, an online journal called Before Farming published a suite of responses in "an informal, non-peer-reviewed context". Among these, Henneberg expanded his microcephalic explanation in collaboration with Alan Thorne, from the Australian National University - which Morwood and Brown rejected. And Colin Groves, also from the ANU, accepted LB1 as a new species, but suggested an earlier hominin than H. erectus as the hobbit's most obvious ancestor - with which they later concurred.
Almost two years later, Henneberg, with collaborators including Thorne and Indonesia's most senior paleoanthropologist, Professor Teuku Jacob, published a paper in the Proceedings of the National Academy of Sciences. LB1 was "drawn from an earlier pygmy H. sapiens population but individually shows signs of a developmental abnormality, including microcephaly", they said. Other remains found in the cave shared LB1's "small body size but not [its] microcephaly".
Two months on, another researcher's publication explained the specimen's characteristics through mutations involving growth hormones and a particular family of genes, while yet another supported the microcephalic-human theory through comparisons between LB1's lower jawbone and a similar one some 3000 years younger. A group of Israeli researchers suggested that the hobbit had suffered Laron syndrome, caused by a growth-hormone-receptor defect "described in several countries in South East Asia". A group of Australians suggested cretinism, noting that this would have led to the hobbit being born "without a thyroid ... leading to severe dwarfism and reduced brain size". And a South African researcher found a cache of other small remains on the Micronesian island of Palau, citing them as further evidence of island dwarfing and thereby undercutting the hobbit's claim to being a distinct species.
Adding drama to an already crowded story was the removal of the bones themselves - theft, said some; cultural misunderstanding, said others - by Indonesia's Professor Jacob. Returned several months later, they were found to be damaged, and Lorraine Cornish was flown from London's Natural History Museum to Jakarta to report on and conserve as much as she could in five days. "Some were in quite a poor condition; some were broken," she explains. "Some moulding had been done, and a lot of moulding compounds were still on the cranium; that was a bit sad, because you can do that sort of thing without damaging a specimen. The pelvis was very badly damaged - I used quite a lot of gap filler there ... and one of the jaws: if you look at high-resolution pictures of it you can see glue's been stuck down the sides where it was broken." Cornish cleaned most of the bones, secured their fragile, friable surfaces, and reboxed the material. She did not see any sign of dental work on the hobbit's teeth: "No ... I'd have noticed something like that." As a conservator, she says, "I don't care what it is. So I'd definitely have said, ‘What's going on here?'"
Earlier this year, Maciej Henneberg suggested a radically different explanation for LB1: he was actually a short male (LB1's sex had long been contested) who had lived on Flores in the 1930s and had seen a dentist. Henneberg claimed he could see evidence of dental work in one of the teeth. "It's still a suspicion," he says. "I'm 95% convinced - but 95, not 100." He called for X-rays, for radiocarbon dating of the bone tissue. The proposed storylines for the hobbit now ran the gamut from revolutionary paleoanthropological find to an early example of a drilled filling.
Before me is a floor tiled with pages about Homo floresiensis: a mosaic of information about wrists, shoulders, tools, microcephaly and dental drills, with dark stripes of varnished board visible in between. It resembles pictures of the Flores skeleton itself: thin lines of pale bone against the black space in which its ribs, its shoulder blades, its vertebrae would sit. The image of a jigsaw often comes up in conversations about paleoanthropology in general, and the hobbit in particular: it's like doing a jigsaw, researchers say, with most of the pieces missing and no picture on the box.
From the sidelines, how can ordinary readers unravel the hobbit's story? Both sides of the debate boast leading academics with illustrious CVs. Both publish in objective, peer-reviewed publications, often associated with the world's most prestigious scientific institutions. Someone says black, someone says white, and even a fleeting knowledge of scientific processes - the rule of parsimony that demands that things connect or behave in the simplest way, or the recognition that science works with hypotheses, necessarily testable and thus necessarily disprovable - does not help. As each finding came out, responses and retaliations came from the opposing side, often in scientific forums and in scientific parlance: "it is premature to conclude ..." "we also note another concern ..." "the conclusions in this paper are not supported." But sometimes they were presented in less traditional arenas and in less neutral language. One professor dismissed a paper as "a rather large and stinky pile of misinformation and wild speculation". "The more I read," said another academic of another publication, "the more I am convinced it is complete nonsense." And sometimes things got far more personal.
The relationship between science and the media can be uneasy. Scientists are often anxious that journalists will sensationalise their work; journalists will often simplify science for a general readership. Journalism also likes the idea of objectivity, but this can mean overplaying one side in an attempt to present what it assumes should be an equally weighted, two-sided story. "Climate science is a good example," says Tocheri. "You had a wealth of scientific evidence and a majority of the area's experts in agreement - but you will still always have a few die-hards. Now, in some debates, their unreasonableness proves worthwhile and they end up being correct. It's part of what makes the scientific process work. But it can be frustrating when they're not really paying attention to the current evidence at hand." In the case of the hobbit, says Mike Morwood, there is "a whole body of evidence. To flippantly dismiss the published evidence, and all the associated evidence, that's not scientific. You can't just pull one thing out and talk about it. And so the criticisms never worried me. I always regarded them as of historical interest."
Two people who have been following the hobbit's story are the Australian film-maker Simon Nasht, whose early hobbit broadcasts led to a full-length documentary, now in post-production, and the prolific blogger John Hawks, an assistant professor of anthropology at the University of Wisconsin, Madison. "I think the general public's impression is: The hobbit? That funny thing? Wasn't it a crippled dwarf?" Nasht says. "But I think the clincher for the species' advocates was Matt Tocheri's wrist paper - most of the sceptics have been silent since then."
Attracting around 5000 readers a day, John Hawks' blog has tracked this story since it began: "I ran down the hall with the paper and said, ‘This looks like an australopithecine and it's only 18,000 years old - what a shocking thing.'" He's tried to sit on the fence ever since, analysing each piece of work as it came forward: when Peter Brown rebutted Maciej Henneberg's claims about the hobbit's dentistry on his own website, he sent Hawks the link for his. "I don't think either side is approaching it wrongly," Hawks says. "I understand they have different assumptions, but I think they're both equally scientific, and I want to explain why that is." Still, he "can see the scenario that would lead to a species of hominids with small brains on an island, where a lot of the critics can't wrap their mind around the idea that humans could shrink their brains". As Hawks sees it, the disagreements often come down to "philosophical differences about how historical hypotheses about the past should be tested and approached ... we weren't there 18,000 years ago; we can't get in a time machine. So we have to decide how we evaluate the evidence we have. And people approach that process in very different ways."
The arguments are about more than this one skeleton. If the hobbit has the ancient pedigree its discoverers suspect it of having, and is in East Asia, then a lot of larger ideas about how and where humans evolved might well require rethinking. If the hobbit was capable of things like toolmaking, then what we regard as modern behaviour is in doubt, too. For one thing, says Paul Taçon, from Griffith University, who wrote an early paper on the matter, we'd need to reassess our understanding of human potential and creativity "in relation to brain size and structure"; for another, it might emphasise the point that "there's a lot of our brain we don't actually use."
"H. floresiensis indicates that the first species out of Africa was probably not H. erectus," says Morwood. "It was probably a species that was small-bodied and small-brained, with primitive body proportions. And the only hominin species out of Africa with primitive body proportions is H. floresiensis." And, Tocheri says, it never hurts to get people thinking about human evolution: "Even in the scientific community, people often don't want to talk about evolution in humans." Natural selection might have presented various scenarios for other animals' evolution, but humans often prefer to think that one evolutionary line led us to where we are now.
One thing to remember, Hawks says, is if "you find a new species, it might be years and years before you find another example and can test your new ideas." In Australasian Science last March, Colin Groves wrote of the "long and inglorious tradition of raspberries directed at new and important discoveries in hominin fossils". ("Raspberries," he says, "yes, I do think that's the word.") Finds of specimens now accepted as Neanderthal, an earlier species of Homo, were "greeted with scornful, patronising, often openly rude comments, and ironically many of the detractors interpreted them as mere pathologies". But then there was the Piltdown Man hoax - a specimen presented as a new species in 1912 that turned out to be made from medieval human, orangutan, chimpanzee, elephant and hippopotamus bits and pieces.
The fragmentary, spare points of reference on which these subjects hang are nowhere more clear than in Henneberg's observation that "only 210 skulls of our human ancestors have been found worldwide, dating back at least 15,000 years." "All the evidence paleoanthropology works with," Simon Nasht says, "you could probably fit in the back of a truck." This makes not only the finds themselves important, but also the traction and consideration they get, and this can be influenced by their name. Although universally adopted, the hobbit moniker was not universally admired. Peter Brown wasn't keen, Morwood confesses, although he calmed down from "apoplectic" when the team decided not to call LB1 Homo hobbitus. Richard Dawkins published a "heartfelt plea" in London's Times: "Please, let's not call these wonderful little creatures hobbits." Such a fictional epithet, he feared, might "diminish the wonder of this sensational discovery".
As Morwood, the archaeologist, sensed, a good nickname was one thing, but it was important that LB1 be designated Homo, like us. "If we called it Sundanthropus" - an entirely new genus that Brown initially suggested - "people would say, ‘This is just a weird little thing, curious, but a side branch of evolution, so we don't care.' In fact, it reflects back on the greater complexity of what might have been happening in Africa." Einstein made the larger point neatly: "We still do not know one-thousandth of one per cent of what nature has revealed to us."
The bones of LB1 lie in their box in Jakarta's National Research Centre for Archaeology. "So small," says Lorraine Cornish, "and kind of insignificant - until you look at them closely. Then you feel a sense of awe: this material, in the ground so long, dug up, and now so controversial." Whoever these bones belonged to, and whatever journeys led their owner - or their ancestors - to Flores, the journey they've made since re-emerging in 2003 has surely been more extraordinary. All that paper on my floor is only a sliver of the archive: Mike Morwood lists initial interest from 7000 newspapers and 98,000 websites, and the repository continues to grow. His book The Discovery of the Hobbit, written with an exuberant dash of adventure, was published in 2007; Maciej Henneberg's fiercely critical Hobbit Trap was published in April this year. The Journal of Human Evolution has a suite of papers analysing Homo floresiensis on the way; available online from September, they'll be published together in 2009. And Simon Nasht's documentary will screen in Australia, America, Canada, France, Germany and Japan later this year.
New techniques have been devised; new projects have been imagined and initiated. "It energised science and debates," says Henneberg. "It's been an organising force for research." Now, teams are heading back to Liang Bua, and to sites in Sulawesi, Timor, other parts of Flores, and beyond. And Debbie Argue and Colin Groves, from the ANU, hope to start hunting the hobbit's ancestor. It's gratifying, Groves says, to work on something so engaging: "Nobody's interested in my palm civets, for instance, so it's nice to find you're part of a bigger conversation."
Some say only more skulls can quell any doubts about H. floresiensis; some say ancient DNA would do it. Analysis of skeletal fragments by the Max Planck Institute, in Leipzig, revealed only modern DNA, which scientific practice reads as implying not that the hobbit was, after all, a modern specimen, but that the sample had been contaminated. Still the sceptics shake their heads, and everyone waits to see if someone else can get a different result. And from the anthropological end of the spectrum comes another suggestion. "Lots of people want to believe," Paul Taçon says, "and I think belief plays a large role in this debate. All of us, no matter where we're from, have ancestral stories or myths about little beings, and many people just wanted to believe that it was true, that these other creatures existed while our ancestors were around."
Mike Morwood sits in his room at the University of Wollongong, his desk covered with the paperwork of files, funding applications, maps. With his long pulled-back hair and energetic manner, he has, as some have noted, a touch of Indiana Jones about him. To talk with him about H. floresiensis is to be swept along on a wave of passion and enthusiasm - not only for her, but for all the things she is leading him to, directly or indirectly. "The next thing," he says, "the next thing we find - that's where it's at." He flicks through photographs of LB1's anatomy, talking about the scope of the original research in Flores and the vastly expanded scale he's thinking on now. "OK. The Kimberley: there are some doozey sites there. Irian Jaya, Sulawesi, Moluku, Timor ... imagine having that large an area ..." He opens an image of the Liang Bua cave, a glorious cathedral. "It's an amazing, amazing site. I remember after we got the Nature paper published, Peter Brown said, ‘Thank goodness that's over - now I can get back to my real research.'" Morwood laughs, and clicks the image closed. "Think again, Peter."
Ashley Hay won last year’s Bragg UNSW Prize for Science Writing. Her last novel, The Railwayman’s Wife, won the Foundation for Australian Literary Studies’ Colin Roderick Award and the People’s Choice category in the NSW Premier’s Literary Awards. Her new novel, A Hundred Small Lessons, will be published this April. She lives in Brisbane.