Evidence Of The 'Lost World': Did Dinosaurs Survive The End Cretaceous Extinctions?

The Lost World, Sir Arthur Conan Doyle's account of an isolated community of dinosaurs that survived the catastrophic extinction event 65 million years ago, has no less appeal now than it did when it was written a century ago. Various Hollywood versions have tried to recreate the lost world of dinosaurs, but today the fiction seems just a little closer to reality.

New scientific evidence suggests that dinosaur bones from the Ojo Alamo Sandstone in the San Juan Basin, USA, date from after the extinction, and that dinosaurs may have survived in a remote area of what is now New Mexico and Colorado for up to half a million years. This controversial new research, published today in the journal Palaeontologia Electronica, is based on detailed chemical investigations of the dinosaur bones, and evidence for the age of the rocks in which they are found.

"The great difficulty with this hypothesis -- that these are the remains of dinosaurs that survived -- is ruling out the possibility that the bones date from before the extinction," says Jim Fassett, author of the research.

"After being killed and deposited in sands and muds, it is possible for bones to be exhumed by rivers and then incorporated into younger rocks" he explains. This is not the usual way in which fossil deposits of this kind form, but it has been shown to explain some other post-extinction dinosaur bones. Fassett has amassed a range of evidence that indicates that these fossils from the Ojo Alamo Sandstone were not exhumed and redeposited and that these dinosaurs really did live after the end Cretaceous extinction event.

The first step must be to demonstrate that the rocks containing the bones are younger than the extinction event. Fassett has analysed the magnetic polarity of the rocks, and the pollen grains they contain, different approaches to finding the age of rocks which, he concludes "independently indicate that they do indeed post-date the extinction".

Fassett also found that "the dinosaur bones from the Ojo Alamo Sandstone have distinctly different concentrations of rare earth metal elements to the bones in the underlying Cretaceous rocks" and this, he argues, "makes it very unlikely that the post-extinction bones were exhumed from the underlying sediments." This is supported by a find of 34 hadrosaur bones together -- "these are not literally an articulated skeleton, but the bones are doubtless from a single animal" -- if the bones had been exhumed by a river, they would have been scattered.

So does this provide conclusive proof that dinosaurs survived the Cretaceous extinctions? According to David Polly, one of the editors of the journal in which the research is published, "this is a controversial conclusion, and many palaeontologists will remain sceptical", but we already know that flying theropod dinosaurs (more generally referred to as birds) and crocodiles survived, so the possibility of pockets of survivors of other types of dinosaur is not quite as far fetched as it might sound.

Finding conclusive evidence, however, is a difficult matter when the crime scene is 65 million years old. "One thing is certain," continues Polly, "if dinosaurs did survive, they were not as widespread as they were before the end of the Cretaceous and did not persist for long." The 'Lost World scenario' of humans and dinosaurs existing at the same time, still belongs firmly in the realms of pure fantasy.

Scientists Discover Largest Orb-weaving Spider

The findings are published in the Oct. 21 issue of the journal PLoS ONE. Matjaž Kuntner, chair of the Institute of Biology of the Slovenian Academy of Sciences and Arts and a Smithsonian research associate, along with Jonathan Coddington, senior scientist and curator of arachnids and myriapods in the Department of Entomology at the Smithsonian's National Museum of Natural History, also reconstructed size evolution in the family Nephilidae to show that this new species, on average, is the largest orb weaver known. Only the females are giants with a body length of 1.5 inches (3.8 centimeters) and a leg span of 4-5 inches (10-12 centimeters); the males are tiny by comparison.

More than 41,000 spider species are known to science with about 400-500 new species added each year. But for some well-known groups, such as the giant golden orb weavers, the last valid described species dates back to the 19th century.

Nephila spiders are renowned for being the largest web-spinning spiders. They make the largest orb webs, which often exceed 3 feet (1 meter) in diameter. They are also model organisms for the study of extreme sexual size dimorphism and sexual biology.

Giant golden orb weavers are common throughout the tropics and subtropics. Thousands of Nephila specimens that have been collected are in natural history museums. Past taxonomists collectively recognized 150 distinct Nephila species, but in his doctoral thesis, Kuntner recognized only 15 species as valid. Linnaeus described the first Nephila species in 1767, and Karsch described the last genuinely new Nephila in 1879. All more recent descriptions turned out to be synonyms.

"It was surprising to find a giant female Nephila from South Africa in the collection of the Plant Protection Research Institute in Pretoria, South Africa, that did not match any described species," said Kuntner, who first examined the specimen in 2000.

Kuntner, Coddington and colleagues launched several expeditions to South Africa specifically to find this species, but all were unsuccessful, suggesting that perhaps the Nephila specimen, first collected in 1978, was a hybrid or perhaps an extinct species. In 2003 a second specimen from Madagascar (in the Naturhistorisches Museum Wien in Vienna, Austria) suggested it was not a hybrid. No additional specimens turned up among more than 2,500 samples from 37 museums. The species seemed extinct. Then a few years ago a South African colleague found a male and two females in Tembe Elephant Park, and it became clear that the specimens were indeed a valid new species.

In the PLoS ONE paper, Kuntner and Coddington described N. komaci as a new species, now the largest web-spinning species known, and placed it on the evolutionary tree of Nephila. They then modeled evolution to test if natural selection had affected body size. They found strong evidence that it had, but only in females. Nephila females consistently through time increased in size and, mainly in Africa, a group of giant spiders evolved. Nephila males, in contrast, did not grow larger, but instead remained about five times smaller than their mates. Although males look like "miniatures" next to their mates, the males are actually normal-sized; the females are giants.

The new species was named after Kuntner's best friend Andrej Komac, who died in an accident at the time of these discoveries. "My friend, himself a scientist, encouraged me to tackle this PhD, but did not live to see the discoveries made," said Kuntner. "He was a big inspiration, and a great friend, thus it was logical to name this new species to his memory."

Kuntner and Coddington urge the public to find new populations of N. komaci in Africa or Madagascar, both to facilitate more research on the group, but also because the species seems to be extremely rare. "We fear the species might be endangered, as its only definite habitat is a sand forest in Tembe Elephant Park in KwaZulu-Natal," said Coddington. "Our data suggest that the species is not abundant, its range is restricted and all known localities lie within two endangered biodiversity hotspots: Maputaland and Madagascar."

Satellite Reveals Surprising Cosmic 'Weather' At Edge Of Solar System

The first solar system energetic particle maps show an unexpected landmark occurring at the outer edge of the solar wind bubble surrounding the solar system. Scientists published these maps, based mostly on data collected from NASA's Interstellar Boundary Explorer satellite, in the Oct. 15 issue of Science Express, the advance online version of the journal Science. "Nature is full of surprises, and IBEX has been lucky to discover one of those surprises," said Priscilla Frisch, a senior scientist in astronomy & astrophysics at the University of Chicago. "The sky maps are dominated by a giant ribbon of energetic neutral atoms extending throughout the sky in an arc that is 300 degrees long." Energetic neutral atoms form when hot solar wind ions (charged particles) steal electrons from cool interstellar neutral atoms.

IBEX was launched Oct. 19, 2008, to produce the first all-sky maps of the heliosphere, which reaches far beyond the solar system's most distant planets. Extending more than 100 times farther than the distance from Earth to the sun, the heliosphere marks the region of outer space subjected to the sun's particle emissions.

The new maps show how high-speed cosmic particle streams collide and mix at the edge of the heliosphere, said Frisch, who co-authored three of a set of IBEX articles appearing in this week's Science Express. The outgoing solar wind blows at 900,000 miles an hour, crashing into a 60,000-mile-an-hour "breeze" of incoming interstellar gas.

Revealed in the IBEX data, but not predicted in the theoretical heliosphere simulations of three different research groups, was the ribbon itself, formed where the direction of the interstellar magnetic field draping over the heliosphere is perpendicular to the viewpoint of the sun.

Energetic protons create forces as they move through the magnetic field, and when the protons are bathed in interstellar neutrals, they produce energetic neutral atoms. "We're still trying to understand this unexpected structure, and we believe that the interstellar magnetic forces are associated with the enhanced ENA production at the ribbon," Frisch said.

IBEX shows that energetic neutral atoms are produced toward the north pole of the ecliptic (the plane traced by the orbit of the planets around the sun), as well as toward the heliosphere tail pointed toward the constellations of Taurus and Orion. "The particle energies change between the poles and tail, but surprisingly not in the ribbon compared to adjacent locations," Frisch said.

Your Insurance Premium May Be Affected By Global Warming

The last decade or so have not been a particularly good one for the UK insurance industry. It seems that at least once a year the UK insurance industry gets to feel the bit of a natural disaster somewhere in the world.

In more case than not, environmentalist will then go on record as saying the natural disaster was avoidable, but for the fact that we are subject to ongoing global warming, which we should only expect to get worse. And, the simple fact is that this trend of global climate change may severely affect your insurance premium.

For the 5 year period from 1998 to 2003 (the last on public record), weather related insurance claims in the UK amounted to £6 billion. This figure is almost double that paid out during the 5 period immediately prior to this. In this regard, it doesn't take long to realise that UK insurance companies set their premiums based on what they calculate the chances are of them having to payout under the insurance policy are.

So, if the chances of having to pay out on an insurance policy for weather related damages have risen twice in the last 5 years, then it wouldn't be unfair to assume that weather related claims could double again in the next 5 years. On this basis, the amount of premium you paid 5 years ago will have quadrupled in 5 years time! However, with industry experts suggesting that future weather related insurance claims could leave many UK insurance companies in financial difficulties, you may well find that loss adjustors determine that the risk has increased significantly more than this, and set a premium suitably high to reflect this point.

Unfortunately, the only way that you can reduce your insurance premiums is to give the UK insurance company reason enough for them to believe that it is unlikely (or less likely) that you'll make a claim against the insurance company. Nonetheless, when it comes to house insurance, you can hardly reduce the chance that a natural disaster won't happen; because that's out of your hands. As such, as the policyholder you need to consider alternative ways if you want to make sure that your insurance premiums do not rise dramatically.

The only real alternative that is left to policyholders is to increase the minimum payout claim threshold. By the minimum payment payout threshold, what is meant is that you agree not to claim on the insurance unless a minimum amount of damage has been done to your property by the weather. By increasing this sum, you may be able to hold off on the prospect of having dramatic increases in your annual home insurance policy.

The only other alternative left open to you is to picket you government and ask them to take the issue of global warming seriously. If that were to happen, and there was to be less chance of the natural disaster happening, then this would reduce the level of risk of the insurance company having to payout under the policy and this reduction of risk should be reflected in a reduction in your insurance premiums.

Geographic Influence The Spread of HIV

Scientists studying biology and geography may seem worlds apart, but together they have answered a question that has defied explanation about the spread of the HIV-1 epidemic in Africa. Writing in the September issue of AIDS, a research team led by scientists at the University of Florida explained why two subtypes of HIV-1 — the virus that causes acquired immunodeficiency syndrome, or AIDS — held steady at relatively low levels for more than 50 years in west central Africa before erupting as an epidemic in east Africa in the 1970s.

Essentially, the explanation for the HIV explosion — obscured until now — involves the relative ease with which people can travel from city to city in east Africa as opposed to the difficulties faced by people living in the population centers of the Democratic Republic of Congo, the point where HIV emerged from west central Africa in its spread to the east.

Later, as the epidemic raged in the east, cities in the Democratic Republic of Congo — a vast country almost as big as all of Western Europe — remained disconnected and isolated, explaining why the virus affected only about 5 percent of the country's population, a level that has not changed much since the 1950s.

"We live in a world that is more interconnected every day, and we have all seen how pathogens such as HIV or the swine flu virus can arise in a remote area of the planet and quickly become a global threat," said Marco Salemi, an assistant professor of pathology, immunology, and laboratory medicine at the UF College of Medicine and senior author of the study. "Understanding the factors that can lead to a full-scale pandemic is essential to protect our species from emerging dangers."

Investigators used databases, including GenBank from the National Center for Biotechnology Information, as well as actual DNA samples, including samples recently collected in Uganda — the vicinity where HIV entered east Africa — to follow the virus' molecular footprints since its emergence in the 1920s.

"HIV mutates rapidly," said Rebecca Gray, a postdoctoral associate in the department of pathology, immunology and laboratory medicine. "This is a successful strategy for the virus, because it evolves quickly and develops drug resistance. But we can use these changes in the genome to follow it over time and develop a history of its progress."

Researchers wanted to know why, the virus smoldered during the 1950s and `60s, before spreading like wildfire through east Africa in the 1970s.

A fateful piece of the puzzle came in the form of geographic information system data, which uses satellite imagery and painstakingly takes into account the availability and navigability of roads between population centers, transportation modes, elevation, climate, terrain and other factors that influence travel.

"We were able to use geographic data to interpret the genetic data," said Andrew J. Tatem, Ph.D., an assistant professor of geography in the College of Liberal Arts and Sciences and a member of UF's Emerging Pathogens Institute. "Genetic data showed once HIV moved out of the Democratic Republic of Congo, it expanded fast and moved rapidly across Uganda, Kenya and Tanzania, all while staying at low levels in the DRC. What was happening was the virus was circulating at stable levels in the urban centers of the DRC, but these centers were isolated. Once it hit east Africa, connectivity between population centers combined with better quality transportation networks, and higher rates of human movement caused HIV to spread exponentially."

HIV was prevalent in about 15 percent of the population in Kenya in 1997, although it has since dropped to about 7 percent, according to the Kaiser Family Foundation. As of 2007, an estimated 22 million people were living with HIV/AIDS in sub-Saharan Africa. About 1.1 million Americans have HIV or AIDS, and an estimated 5.1 million people in India are HIV-positive. In Eastern Europe, HIV infections more than doubled from 420,000 in 1998 to 1 million in 2001.

"If we can predict the specific routes of an epidemic, we can find the geographic regions more at risk and target these areas with medical intervention and strategies for prevention," Salemi said. "In terms of health-care applications, coupling genetic analysis with geographic information systems can give us a powerful tool to understand the spread of pathogens and contain emerging epidemics."

Working with Maureen M. Goodenow, Ph.D., the Stephany W. Holloway university chair for AIDS research at the UF College of Medicine, UF researchers collaborated with an array of scientists hailing from the National Institute of Allergy and Infectious Diseases, the Rakai Health Sciences Program and Makerere University of Uganda, and the Johns Hopkins University. They refer to the combination of techniques that led to the discovery as "landscape phylodynamics."

"It is the first study that has given us a clear picture of epidemic history of HIV in east Africa, including the geographic routes and the time scale that it occurred," said Oliver Pybus, Ph.D., a researcher in the department of zoology at Oxford University who did not participate in the study. "Genetic analysis of the HIV genome provides the family tree of the virus, combined with spatial analysis of high-resolution data of land use, topology and other factors. There is a huge potential in doing that kind of analysis, but it requires a rare combination of specialists in different fields to come together."