Life

by Tim Flannery

  Not all male sexual appurtenances, however, are attractive to humans. It’s hard to discern the seductive powers of the ‘standards’ borne by the standard-wing nightjar. Perhaps the female chooses the males with the largest standard feathers because they represent the greatest handicap to their owner. Although this sounds nonsensical, it makes good evolutionary sense, for the bearers of such ‘handicaps’ are in effect proclaiming, ‘Look at me! I’ve grown into a big strong male even while carrying these cumbersome handicaps, so my genes must be extra good. They will benefit your daughters, who will not bear my handicaps, while your son’s handicaps will attract females as well!’

  Despite our shared genetic heritage, our concept of beauty is largely dependent on the nature of our senses. We can appreciate the beauty of a bird of paradise because, like us, birds are visual creatures. For all their grotesquery, seadevils must be attractive to other seadevils, otherwise there would be none, though just where the attraction lies is beyond my reckoning. Perhaps it is a scent, touch, or movement that makes the male seadevil swoon. Whatever it is, it’s a near-fatal attraction, for the male seadevil is tiny compared with his mate, and when he encounters her he does not seek to copulate, but instead bites her, never to let go. The two grow together, and in some species the male’s head becomes embedded in the body of the female. Nurtured solely by her blood, he becomes nothing but a dependent testicle that is somehow instructed by the female (perhaps through hormones) to release sperm at her command.

  While the need for sex can lead to truly astonishing adaptations, a need for security can also manifest itself in the most intriguing evolutionary strategies. The humble shield-tailed agama lizard has transformed its tail into a knobby door-stopper, while the flamboyant crest of the sail-tailed lizard may help it leap to safety. Vanishing is another form of defence. The bay owls are so good at it that one species, the African bay owl, remained unknown to science until 1951 when a single specimen was found. It was 1996 before another one was sighted. Some fish have elevated vanishing to an art form. The most spectacular disappearing acts are performed by pipefish and seadragons, yet outside their environment they are among the most flamboyant creatures imaginable. Some animals have even been driven to ignominy by their need to hide—witness the screaming Budgett’s frog, which looks like a turd left by a tapir at a waterhole.

  We hope that this book provides an opportunity to consider animals outside the everyday perception of their place, and that of other creatures, in nature. Firstly consider how a dog lives—through its nose: tracking people by scent along a busy street, ‘smelling’ illnesses such as cancer and somehow anticipating earthquakes, yet all the while seeing the world myopically in black and white. To imagine the very different life of the hairy seadevil, however, does lift us into another realm, for not only is its sex life bizarre but its habitat is too. Imagine living at pressures that would crush us in an instant, in a world of impenetrable darkness and frigid cold, where there exists no edges or ends—just an eternity of space.

  When imagining such realms, remain alert, for things are not always what they seem. Even this book has its own trap. One of the creatures depicted here does not exist at all outside the imagination. I wonder if you can discover which one it is?

  The Priest and the Hobbit

  2004

  NOT SO VERY long ago, in a faraway corner of the western Pacific Ocean, there was an enchanted isle, and it was a home to hobbits. Its hills and caves were the haunts of ferocious dragons and enormous rats, and through its forests roamed elephants no larger than ponies. This magical place did not know man, for no human had ever trod its hills. Instead it was a realm of diminutive, almost-human beings whose heads would not have reached your waists. They may have been small, but they were very brave, for they fought the dragons and drove the giant rats from their lairs.

  You could be forgiven for thinking that this all sounds like a fantasy, and until a spectacular discovery in 2004 it was. The mystical-sounding place is the island of Flores in eastern Indonesia, and the hobbit is now officially known as Homo floresiensis. Her existence was announced to the world in October in the prestigious science journal Nature, and the discovery of her skeleton is a finding without parallel, in fact it is so astonishing as to stretch credulity.

  The island of Flores lies east of Java and Bali, in the middle of a long chain of islands known as Nusa Tenggara that stretches, with only short gaps, from Java almost all the way to New Guinea. At the western end of the archipelago, between Bali and Lombok, runs Wallace’s line, a hypothetical boundary first recognised by the nineteenth-century zoologist Alfred Russel Wallace as the place where the faunas of Asia and Australia abut. Bali supports (or at least once did), a rich Asian fauna of monkeys, wild cattle, deer, elephants and tigers. Lombok, however, has a very different and much poorer fauna, including peculiarly Australian species such as honeyeaters and cockatoos.

  Today the only native mammals on Flores are rats. Their ancestors must have reached the island long ago, perhaps on rafts of vegetation washed out to sea during floods. In the absence of competitors the rats have made Flores their own, diversifying spectacularly. One of the most imposing is Pappagomys amandavillei. The best part of a metre long, it is a monstrous relative of the house rat, and it even smells like one. Fossils attest to the fact that many of the islands of Nusa Tenggara once swarmed with similar giant rats, but today Pappagomys is the only survivor, the other islands having lost their giant rats thousands of years ago.

  Another remarkable Floresian survivor is the Komodo dragon. This giant monitor lizard—almost three metres long and over 100 kilograms in weight—is the world’s largest. Once it was also found throughout Nusa Tenggara, but today it survives only in eastern Flores and on nearby Komodo Island, east of Flores.

  Until Dutch archaeologist Father Theodore Verhoeven began to investigate Flores’ past, rats and dragons were thought to be the only large land animals ever to have inhabited the island. Then, in 1965, Verhoeven excavated a large pit in a cave known as Liang Bua, which is located in a mountain area of eastern Flores. He was intrigued to discover the remains of a kind of elephant known as a Stegodon. Although Stegodons are entirely extinct today, they were once common throughout South-East Asia, and the Floresian one was rather special, for it was an island dwarf, a descendant of normal-sized elephants that had drifted to the island and which, in adapting to the limited resources available there, had shrunk to the size of ponies.

  Father Verhoeven’s pioneering investigations indicated that, of the great diversity of species inhabiting South-East Asia, just two types of land mammals—rats and elephants—had made the sea-crossings required to reach Flores. It may seem odd that only the largest and smallest of Asia’s mammals were successful, but this pattern is common in the world’s islands, many of which once supported rats and elephants that had reached them from adjacent mainlands. It may also seem odd that, having arrived, these very large and very small creatures began to converge in size—the rats growing larger and the elephants shrinking. But again this pattern is widespread and is due to selection for the appropriate body size to exploit an island’s limited resources. On Flores the process was so advanced that we can guess that it had been in progress for a million years or more.

  Both the elephants and rats presumably fell prey to the island’s Komodo dragons. The ancestral homeland of the Komodos is Australia, and until 50,000 years ago an enormous Komodo relative that may have reached five metres in length lived there. In the absence of predators such as tigers, dwarfed descendants of this monster spread throughout most of Nusa Tenggara, becoming established on myriad islands from Australia to its eastern limit of Komodo Island.

  Father Verhoeven made one further discovery in Liang Bua that saw archaeologists return to the cave again and again. Along with the elephant teeth, he unearthed an assortment of stone tools, indicating that toolmakers must have reached the island. But who were they?

  Between 1978 and 1989 R.P. Soejono, an Indonesia
n archaeologist, excavated ten more pits at Liang Bua but discovered nothing substantial to identify the toolmaker. Then, in 2001 a team of Australians led by Dr Mike Morwood joined Soejono. They expanded four of his excavations, including the only one lying adjacent to the eastern wall of the cave. It was here, in early 2004, at a depth of nearly six metres, that the toolmaker herself was finally found.

  She was unearthed in the final fortnight of the dig. The Australians had already left and the Indonesians were working alone. When they found the skeleton it was as soft as tissue paper, and the delicate work of uncovering, drying and hardening it was painstaking. When she was finally clear of the earth, however, it was evident that the skeleton was female and surprisingly complete—lacking only the arms—providing ample proof of the appearance of its owner.

  In life she would have weighed around sixteen kilograms and stood just ninety-five centimetres tall. She was entirely upright in her stance, but her forehead was low and the brain below was no larger than that of a chimp, which is not entirely a fair comparison as her body is so tiny compared with that of chimps. A thick ridge of bone protected her eyes, and she had no chin, all of which made it abundantly clear that she was not human.

  Indeed, her skeleton bore unmistakable similarities to that of Homo ergaster, an ancient ancestor of ours that flourished in Africa around 1.8 million years ago. Ergaster was the first hominid to leave Africa, and as evidenced by the famous Java Man fossils, had reached South-East Asia at least a million years ago. What we did not know before the finds at Liang Bua was that ergaster had joined those elite migrators the elephants and rats, and had reached Flores.

  Sufficient finds have been made at Liang Bua to allow for the reconstruction of parts of the hobbits’ lifestyle. They made a number of stone tools, among them wicked-looking stone points that may have been hafted on a stick. An abundance of newborn pygmy stegodon teeth in the cave suggests that the hobbits hunted newborn elephants, perhaps using spears. Abundant bones also indicate that they hunted the giant rats, which from nose to tail tip were almost as long as the hobbits were tall. Whatever else their use, I’m sure that the hobbits’ spears were employed to keep Komodo dragons at bay, for these fearsome ambush predators weighed ten times as much as the hobbits, and surely would have eaten them whenever they could.

  There is no evidence that our lady hobbit was laid to rest with any ceremony. Instead her body appears to have been abandoned on the cave floor, perhaps in a pool. Although there is charcoal in the cave sediments, there is no evidence of the systematic use of fire, so perhaps the hobbits enjoyed their baby elephant steaks raw. And the hobbits are such distant relatives of ours that it would be surprising if they talked, though surely they had some efficient means of communication.

  So how did the hobbits meet their end? Perhaps the most astonishing thing about the discovery is how recently the hobbits lived. Until at least 18,000 years ago Flores was well populated with hobbits, and they may have persisted until even more recently. Modern humans began to spread through Nusa Tenggara around 50,000 years ago and, as they moved from Java towards Australia, Flores lay right in their path. The ancestors of Australia’s Aborigines must have met hobbits. They may have overlapped, at least regionally, for 30,000 years; yet there is no evidence of modern humans at Liang Bua. Perhaps people found the mountains of Flores, with their tiny hominids and Komodo dragons, just too spooky and moved on. Whatever the case, a profound mystery exists here, for if modern humans did not kill off the hobbits, then what did?

  The discovery of the Floresian hobbit suddenly clarifies a great deal in biology that was, up until now, mysterious. Genetic studies of head lice, for example, indicate that humans host two species that split more than a million years ago. One of the species evolved on our ancestors, while the other, which is found only in the Americas, must have evolved on a Homo ergaster or Homo erectus-like creature. The astonishing thing is that this louse species appears to have jumped onto human heads around 30,000 years ago. With the exception of the hobbit, Homo ergaster was by then long gone, so perhaps the lice date the time of first contact between us and the hobbit.

  The hobbit helps explain why Flores alone in the great constellation of islands of Nusa Tenggara kept its giant rats and Komodo dragon. On Flores, and Flores only, the rats and dragons had a million years to adapt to the presence of a human-like predator. Presumably, unlike their more naive relatives on other islands, they learned just enough from the experience to avoid extinction when fully modern humans arrived.

  The hobbit also teaches us about ourselves. On reflection, the fact that over a million years ago Homo ergaster joined those few elite mammals that could cross water makes humanity’s spread around the globe during the past 50,000 years somehow less surprising. And the hobbit reminds us that we are like any other species in that, when isolated on islands, evolution will fit our bodies to the opportunities the size of our ‘world’ offers. Thus the hobbit tells us that we are not unique; nor were we, until 18,000 years ago, alone.

  Captain Cook’s Kangaroo

  2004

  IF YOU EVER see a fresh kangaroo carcass lying beside the road it is well worth stopping to take a closer look. There is not an ounce of fat or wasted muscle on their perfectly proportioned frames, and even in death their grace and beauty—which extends from the tips of the slender limbs to their long and curved eyelashes—is sublime. But what kind of kangaroo are you looking at? This is not an easy question to answer, for the larger kangaroos belong to a group of around twenty species that are classified into three genera or subgenera, depending on whom you ask. They are Macropus (the grey kangaroos, whose name means ‘big foot’), Osphranter (a name of obscure origin, for the red kangaroo and euros) and Notamacropus, a name given by Lyn Dawson and me to a dozen or so stripe-faced wallabies, which means ‘striped kangaroo’, but that is also a joke, for we wanted to emphasise that these creatures were ‘not a Macropus’, the genus in which they were once classified.

  For now we will concentrate on the larger kinds—the splendid, desert-dwelling red kangaroo, the euros of the rocky ranges, and the grey kangaroos of Australia’s better-watered south and east. Does your victim of the internal combustion engine have silken fur, a thick white tail and white on the sides of its muzzle? If so it is the grandest of them all, the red kangaroo, which incidentally is not always red, but sometimes grey or red-grey. If the creature has a nose like a dog, your deceased friend is a euro. If, however, it is greyish with dark tips on its tail, hands and feet, and long, straight claws on its toes, it is a grey kangaroo. But you have only just begun your identification. In travelling from Melbourne to Perth, for example, you are likely to encounter two distinctive species of grey kangaroos, while if you travel Australia’s north you may stumble upon as many as three euro species.

  The eastern grey (Macropus giganteus) can be seen in pastures and forests from Cooktown to Tasmania, while the western grey (Macropus fuliginosus, which can be divided into three distinct subspecies) is found from Perth to western New South Wales. In the 1980s I was fortunate enough to meet the man who announced that eastern and western greys were different. Today John Kirsch teaches biology at the University of Wisconsin in Madison, but in the mid-1960s he was an American studying in Australia on a Fulbright Scholarship. John, a ‘confirmed bachelor’ who lives with his dog a little way out of town, describes Madison as ‘The faggot buckle in America’s Bible belt’, a statement others may dispute, but that seemed accurate enough to me. He kindly invited me to stay with him when I visited, and was busy straining rice through an old sock (newly washed, I hoped) when we got onto the subject of grey kangaroos. The kangaroo shooters John spoke to had long recognised two kinds of greys, as had many pastoralists; eastern greys are a clear grey colour and lack a distinctive odour, while western greys are chocolate-coloured and, if male, reek of curry. This rather unexpected odour is produced from a gland on the chest, and were sixteen western greys inhabitants of the subcontinent it may well have led to their early
extinction. But to many Australian nostrils the odour is overwhelming. Roo shooters call the large males ‘stinkers’, and avoid them when they can, and Aborigines such as the Adnymathanha of South Australia prefer other food if it is available. (It is possible that the western grey only entered Adnymathanha country in the Flinders Ranges after European pastoralists dug stock wells.)

  John’s principal method of providing scientific proof involved injecting blood serum from western grey kangaroos into eastern greys and vice versa, as well as injecting serum from both into possums and rabbits. The subsequent intensity of the immune response revealed how close the relationship between the creatures is. In a process known as electrophoresis, he also examined how long it took for various blood chemicals to pass through agar gel when an electric current was applied. As I listened to John I wondered at the readiness with which Australians accept the word of scientists, especially foreign experts, yet so often mistrust their own experiences and observations.

  John’s results were later confirmed by experiments that revealed that the two grey kangaroos had different breeding cycles and were thus unlikely to mate in the wild. Furthermore, hybrids bred in captivity had very limited fertility—rather like the sterile mule that results from a horse–donkey cross—the ultimate test of the distinctness of a species.

  In truth, confusion has surrounded grey kangaroos since the time of James Cook. The first encounter between a man of science and the marsupial was the result of a terrifying accident—a holing of the Endeavour when it ran onto a coral shoal. In desperate need of repairs, the stricken vessel reached the mouth of the Endeavour River in Far North Queensland on 15 June 1770. Judging from the journal of Joseph Banks, the ship’s naturalist, within a week or two everyone but he had seen the amazing kangaroo. It was a frustrating misfortune, for the descriptions of sailors were often hard to fathom; one told a breathless tale of a beast ‘about as large and much like a one gallon keg, as black as the devil, and had two horns on his head. It went but slowly but I dared not touch it.’ Substitute the ‘horns’ for long pointed ears and you have a description of a black flying fox—though it is doubtful whether Banks ever got to the heart of this nautical account.