T-Rex Hunter
A Jack Horner is an unlikely academic: his dyslexia is so bad that he has trouble reading a book. But he can read the imprint of life in sandstone or muddy shale across a distance of 100m years, and it is this gift that has made him curator of palaeontology at Montana State University's Museum of the Rockies, the leader of a multi-million dollar scientific project to expose a complete slice of life 68m years ago, and a consultant to Steven Spielberg and other Hollywood figures.
B His father had a sand and gravel quarry in Montana, and the young Horner was a collector of stones and bones, complete with notes about when and where he found them. "My father had owned a ranch when he was younger, in Montana," he says. "He was enough of a geologist, is a sand and gravel man, to have a pretty good notion that they were dinosaur bones. So when I was eight years old he took me back to the area that had been his ranch, to where he had seen these big old bones. I picked up one. I am pretty sure it was the upper arm bone of a duckbilled dinosaur: it probably wasn't a maiaosaur but closely related to that. I catalogued it, and took good care of it, and then later when I was in high school, excavated my first dinosaur skeleton. It obviously started earlier than eight and I literally have been driven ever since. I feel like I was born this way."
C Horner spent seven years at university but never graduated. "I have a learning disability, I would call it a learning difference – dyslexia, they call it – and I just had a terrible time with English and foreign languages and things like that. For a degree in geology or biology, they required two years of a foreign language. There was no way in the world I could do that. In fact, I didn't really pass English. So I couldn't get a degree, I just wasn't capable of it. But I took all of the courses required and I wrote a thesis and I did all sorts of things. So I have the education, I just don't have the piece of paper," he says.
D In Montana, in those days, everybody had the right to a college education. His grades at high school had been terrible, at university, his advisers recognised that he was having a hard time, and went on helping. The dean who kept readmitting him was to give Horner an honorary doctorate years later. As a young non-graduate, Horner wrote to every museum in the English-speaking world, asking for a job. Los Angeles County Museum and the Royal Ontario Museum in Toronto made offers, but he accepted a post as a technician at Princeton University because of Princeton, New Jersey.
E "We definitely know we are working on a very broad coastal plain with the streams and rivers bordered by conifers and hardwood plants, and the areas in between these rivers were probably fern-covered. There were no grasses at all: just ferns and bushes – an unusual landscape, kind of taking the south-eastern United States – Georgia, Florida – and mixing it with the moors of England and flattening it out," he says. "Triceratops is very common: they are the cows of the Cretaceous, they are everywhere. Duckbilled dinosaurs are relatively common but not as common as triceratops and T rex, for a meat-eating dinosaur, is very common. What we would consider the predator-prey ratio seems really off the scale. What is interesting is the little dromaeosaurs, the ones we know for sure were good predators, we haven't found any of them."
F Which is why he sees T rex, not as the lion of the Cretaceous savannah but its vulture. "Look at the wildebeest that migrate in the Serengeti of Africa, a million individuals lose about 200,000 individuals in that annual migration. There is a tremendous carrion base there. And so you have hyenas, you have tremendous numbers of vultures that are scavenging, you don't have all that many animals that are good predators. If T rex was a top predator, especially considering how big it is, you'd expect it to be extremely rare, much rarer than the little dromaeosaurs, and yet they are everywhere, they are a dime a dozen," he says. A 12-tonne T rex is a lot of vultures, but he doesn't see the monster as clumsy. He insisted his theory and finding, dedicated to further research upon it, of course, he would like to reevaluate if there is any case that additional evidence found or explanation raised by others in the future.
G He examined the leg bones of the T-rex, and compared the length of the thigh bone (upper leg), to the shin bone (lower leg). He found that the thigh bone was equal in length or slightly longer than the shin bone, and much thicker and heavier. Which proves that the animal was built to be a slow walker rather than fast running. On the other hand, the fossils of fast hunting dinosaurs ALWAYS showed that the shin bone was longer than the thigh bone. This same truth can be observed in many animals of today which are designed to run fast: The ostrich, cheetah, etc.
H He also studied the fossil teeth of the T-rex, and compared them with the teeth of the Velociraptor, and put the nail in the coffin of the "hunter T-rex theory". The Velociraptor's teeth were like steak knives: sharp, razor-edged, and capable of tearing through flesh with ease. The T-Rex's teeth were huge, sharp at their tip, but blunt, propelled by enormous jaw muscles, which enabled them to only crush bones.
I With the evidence presented in his documentary, Horner was able to prove that the idea of the T-rex as being a hunting and ruthless killing machine is probably just a myth. In light of the scientific clues he was able to unearth, the T-rex was a slow, sluggish animal which had poor vision, an extraordinary sense of smell, that often reached its "prey" after the real hunters were done feeding, and sometimes it had to scare the hunters away from a corpse. In order to do that, the T-rex had to have been ugly, nasty-looking, and stinky. This is actually true of nearly all scavenger animal. They are usually vile and nasty looking.
Fossil files "The Paleobiology Database"
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Are we now living through the sixth extinction as our own activities destroy ecosystems and wipe out diversity? That's the doomsday scenario painted by many ecologists, and they may well be right. The trouble is we don't know for sure because we don't have a clear picture of how life changes between extinction events or what has happened in previous episodes. We don't even know how many species are alive today, let alone the rate at which they are becoming extinct. A new project aims to fill some of the gaps. The Paleobiology Database aspires to be an online repository of information about every fossil ever dug up. It is a huge undertaking that has been described as biodiversity's equivalent of the Human Genome Project. Its organizers hope that by recording the history of biodiversity they will gain an insight into how environmental changes have shaped life on Earth in the past and how they might do so in the future. The database may even indicate whether life can rebound no matter what we throw at it, or whether a human-induced extinction could be without parallel, changing the rules that have applied throughout the rest of the planet's history.
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But already the project is attracting harsh criticism. Some experts believe it to be seriously flawed. They point out that a database is only as good as the data fed into it, and that even if all the current fossil finds were catalogued, they would provide an incomplete inventory of life because we are far from discovering every fossilised species. They say that researchers should get up from their computers and get back into the dirt to dig up new fossils. Others are more sceptical still, arguing that we can never get the full picture because the fossil record is riddled with holes and biases.
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Fans of the Paleobiology Database acknowledge that the fossil record will always be incomplete. But they see value in looking for global patterns that show relative changes in biodiversity. "The fossil record is the best tool we have for understanding how diversity and extinction work in normal times," says John Alroy from the National Center for Ecological Analysis and Synthesis in Santa Barbara. "Having a background extinction estimate gives us a benchmark for understanding the mass extinction that's currently underway. It allows us to say just how bad it is in relative terms."
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To this end, the Paleobiology Database aims to be the most thorough attempt yet to come up with good global diversity curves. Every day between 10 and 15 scientists around the world add information about fossil finds to the database. Since it got up and running in 1998, scientists have entered almost 340,000 specimens, ranging from plants to whales to insects to dinosaurs to sea urchins. Overall totals are updated hourly at www. paleodb.org. Anyone can download data from the public part of the site and play with the numbers to their heart's content. Already, the database has thrown up some surprising results. Looking at the big picture, Alroy and his colleagues believe they have found evidence that biodiversity reached a plateau long ago, contrary to the received wisdom that species numbers have increased continuously between extinction events. "The traditional view is that diversity has gone up and up and up," he says. "Our research is showing that diversity limits were approached many tens of millions of years before the dinosaurs evolved, much less suffered extinction." This suggests that only a certain number of species can live on Earth at a time, filling a prescribed number of niches like spaces in a multi-storey car park. Once it's full, no more new species can squeeze in, until extinctions free up new spaces or something rare and catastrophic adds a new floor to the car park.
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Alroy has also used the database to reassess the accuracy of species names. His findings suggest that irregularities in classification inflate the overall number of species in the fossil record by between 32 and 44 per cent. Single species often end up with several names, he says, due to misidentification or poor communication between taxonomists in different countries. Repetition like this can distort diversity curves. "If you have really bad taxonomy in one short interval, it will look like a diversity spike – a big diversification followed by a big extinction – when all that has happened is a change in the quality of names," says Alroy. For example, his statistical analysis indicated that of the 4861 North American fossil mammal species catalogued in the database, between 24 and 31 per cent will eventually prove to be duplicated.
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Of course, the fossil record is undeniably patchy. Some places and times have left behind more fossil-filled rocks than others. Some have been sampled more thoroughly. And certain kinds of creatures – those with hard parts that lived in oceans, for example – are more likely to leave a record behind, while others, like jellyfish, will always remain a mystery. Alroy has also tried to account for this. He estimates, for example, that only 41 per cent of North American mammals that have ever lived are known from fossils, and he suspects that a similar proportion of fossils are missing from other groups, such as fungi and insects.
G Not everyone is impressed with such mathematical wizardry. Jonathan Adrain from the University of Iowa in Iowa City points out that statistical wrangling has been known to create mass extinctions where none occurred. It is easy to misinterpret data. For example, changes in sea level or inconsistent sampling methods can mimic major changes in biodiversity. Indeed, a recent and thorough examination of the literature on marine bivalve fossils has convinced David Jablonsky from the University of Chicago and his colleagues that their diversity has increased steadily over the past 5 million years.
H With an inventory of all living species, ecologists could start to put the current biodiversity crisis in historical perspective. Although creating such a list would be a task to rival even the Palaeobiology Database, it is exactly what the San Francisco-based ALL Species Foundation hopes to achieve in the next 25 years. The effort is essential, says Harvard biologist Edward O. Wilson, who is alarmed by current rates of extinction. "There is a crisis. We've begun to measure it, and it's very high," Wilson says. "We need this kind of information in much more detail to protect all of biodiversity, not just the ones we know well." Let the counting continue.
Personality and Appearance
When Charles Darwin applied to be the "energetic young man" that Robert Fitzroy, the Beagle's captain, sought as his gentleman companion, he was almost let down by a woeful shortcoming that was as plain as the nose on his face. Fitzroy believed in physiognomy—the idea that you can tell a person's character from their appearance. As Darwin's daughter Henrietta later recalled, Fitzroy had "made up his mind that no man with such a nose could have energy". This was hardly the case. Fortunately, the rest of Darwin's visage compensated for his sluggardly proboscis: "His brow saved him."
The idea that a person's character can be glimpsed in their face dates back to the ancient Greeks. It was most famously popularised in the late 18th century by the Swiss poet Johann Lavater, whose ideas became a talking point in intellectual circles. In Darwin's day, they were more or less taken as given. It was only after the subject became associated with phrenology, which fell into disrepute in the late 19th century, that physiognomy was written off as pseudoscience.
First impressions are highly influential, despite the well-worn admonition not to judge a book by its cover. Within a tenth of a second of seeing an unfamiliar face we have already made a judgement about its owner's character—caring, trustworthy, aggressive, extrovert, competent and so on. Once that snap judgement has formed, it is surprisingly hard to budge. People also act on these snap judgements. Politicians with competent-looking faces have a greater chance of being elected, and CEOs who look dominant are more likely to run a profitable company. There is also a well-established "attractiveness halo". People seen as good-looking not only get the most valentines but are also judged to be more outgoing, socially competent, powerful, intelligent and healthy.
In 1966, psychologists at the University of Michigan asked 84 undergraduates who had never met before to rate each other on five personality traits, based entirely on appearance, as they sat for 15 minutes in silence. For three traits—extroversion, conscientiousness and openness—the observers' rapid judgements matched real personality scores significantly more often than chance. More recently, researchers have re-examined the link between appearance and personality, notably Anthony Little of the University of Stirling and David Perrett of the University of St Andrews, both in the UK. They pointed out that the Michigan studies were not tightly controlled for confounding factors. But when Little and Perrett re-ran the experiment using mugshots rather than live subjects, they also found a link between facial appearance and personality—though only for extroversion and conscientiousness. Little and Perrett claimed that they only found a correlation at the extremes of personality.
Justin Carre and Cheryl McCormick of Brock University in Ontario, Canada studied 90 ice-hockey players. They found that a wider face in which the cheekbone-to-cheekbone distance was unusually large relative to the distance between brow and upper lip was linked in a statistically significant way with the number of penalty minutes a player was given for violent acts including slashing, elbowing, checking from behind and fighting. The kernel of truth idea isn't the only explanation on offer for our readiness to make facial judgements. Leslie Zebrowitz, a psychologist at Brandeis University in Waltham, Massachusetts, says that in many cases snap judgements are not accurate. The snap judgement, she says, is often an "overgeneralisation" of a more fundamental response. A classic example of overgeneralisation can be seen in predators' response to eye spots, the conspicuous circular markings seen on some moths, butterflies and fish. These act as a deterrent to predators because they mimic the eyes of other creatures that the potential predators might see as a threat.
Another researcher who leans towards overgeneralisation is Alexander Todorov. With Princeton colleague Nikolaas Oosterhof, he recently put forward a theory which he says explains our snap judgements of faces in terms of how threatening they appear. Todorov and Oosterhof asked people for their gut reactions to pictures of emotionally neutral faces, sifted through all the responses, and boiled them down to two underlying factors: how trustworthy the face looks, and how dominant. Todorov and Oosterhof conclude that personality judgements based on people's faces are an overgeneralisation of our evolved ability to infer emotions from facial expressions, and hence a person's intention to cause us harm and their ability to carry it out. Todorov, however, stresses that overgeneralisation does not rule out the idea that there is sometimes a kernel of truth in these assessments of personality.
So if there is a kernel of truth, where does it come from? Perrett has a hunch that the link arises when our prejudices about faces turn into self-fulfilling prophecies—an idea that was investigated by other researchers back in 1977. Our expectations can lead us to influence people to behave in ways that confirm those expectations: consistently treat someone as untrustworthy and they end up behaving that way. This effect sometimes works the other way round, however, especially for those who look cute. The Nobel prize-winning ethologist Konrad Lorenz once suggested that baby-faced features evoke a nurturing response. Support for this has come from work by Zebrowitz, who has found that baby-faced boys and men stimulate an emotional centre of the brain, the amygdala, in a similar way. But there's a twist. Babyfaced men are, on average, better educated, more assertive and apt to win more military medals than their mature-looking counterparts. They are also more likely to be criminals; think Al Capone. Similarly, Zebrowitz found baby-faced boys to be quarrelsome and hostile, and more likely to be academic highfliers. She calls this the "self-defeating prophecy effect": a man with a baby face strives to confound expectations and ends up overcompensating.
There is another theory that recalls the old parental warning not to pull faces because they might freeze that way. According to this theory, our personality moulds the way our faces look. It is supported by a study two decades ago which found that angry old people tend to look cross even when asked to strike a neutral expression. A lifetime of scowling, grumpiness and grimaces seemed to have left its mark.
