Popular Science articles about Paleontology And Archaeology

Mystery human fossils put spotlight on China

Fossils from two caves in south-west China have revealed a previously unknown Stone Age people and give a rare glimpse of a recent stage of human evolution with startling implications for the early peopling of Asia. The fossils are of a people with a highly unusual mix of archaic and modern anatomical features and are the youngest of their kind ever found in mainland East Asia.

Dated to just 14,500 to 11,500 years old, these people would have shared the landscape with modern-looking people at a time when China's earliest farming cultures were beginning, says an international team of scientists led by Associate Professor Darren Curnoe, of the University of New South Wales, and Professor Ji Xueping of the Yunnan Institute of Cultural Relics and Archeology.

Details of the discovery are published in the journal PLoS ONE. The team has been cautious about classifying the fossils because of their unusual mosaic of features.

"These new fossils might be of a previously unknown species, one that survived until the very end of the Ice Age around 11,000 years ago," says Professor Curnoe.

"Alternatively, they might represent a very early and previously unknown migration of modern humans out of Africa, a population who may not have contributed genetically to living people."

The remains of at least three individuals were found by Chinese archaeologists at Maludong (or Red Deer Cave), near the city of Mengzi in Yunnan Province during 1989. They remained unstudied until research began in 2008, involving scientists from six Chinese and five Australian institutions.

A Chinese geologist found a fourth partial skeleton in 1979 in a cave near the village of Longlin, in neighbouring Guangxi Zhuang Autonomous Region. It stayed encased in a block of rock until 2009 when the international team removed and reconstructed the fossils.

The skulls and teeth from Maludong and Longlin are very similar to each other and show an unusual mixture of archaic and modern anatomical features, as well as some previously unseen characters.

While Asia today contains more than half of the world's population, scientists still know little about how modern humans evolved there after our ancestors settled Eurasia some 70,000 years ago, notes Professor Curnoe.

The scientists are calling them the "Red-deer Cave people" because they hunted extinct red deer and cooked them in the cave at Maludong.

The Asian landmass is vast and scientific attention on human origins has focussed largely on Europe and Africa: research efforts have been hampered by a lack of fossils in Asia and a poor understanding of the age of those already found.

Until now, no fossils younger than 100,000 years old have been found in mainland East Asia resembling any species other than our own (Homo sapiens). This indicated the region had been empty of our evolutionary cousins when the first modern humans appeared. The new discovery suggests this might not have been the case after all and throws the spotlight once more on Asia.

"Because of the geographical diversity caused by the Qinghai-Tibet plateau, south-west China is well known as a biodiversity hotspot and for its great cultural diversity. That diversity extends well back in time" says Professor Ji.

In the last decade, Asia has produced the 17,000-year-old and highly enigmatic Indonesian Homo floresiensis ("The Hobbit") and evidence for modern human interbreeding with the ancient Denisovans from Siberia.

"The discovery of the red-deer people opens the next chapter in the human evolutionary story -- the Asian chapter -- and it's a story that's just beginning to be told," says Professor Curnoe.

Study suggests link between H. pylori bacteria and blood sugar control in adult Type 2 diabetes

A new study by researchers at NYU Langone Medical Center reveals that the presence of Helicobacter pylori (H. pylori) bacteria is associated with elevated levels of glycosylated hemoglobin (HbA1c), an important biomarker for blood glucose levels and diabetes. The association was even stronger in obese individuals with a higher Body Mass Index (BMI). The results, which suggest the bacteria may play a role in the development of diabetes in adults, are available online in The Journal of Infectious Diseases.

There have been several studies evaluating the effect of the presence of H. pylori on diabetes outcomes, but this is the first to examine the effect on HbA1c, an important, objective biomarker for long-term blood sugar levels, explained Yu Chen, PhD, MPH, associate professor of epidemiology at NYU School of Medicine, part of NYU Langone Medical Center.

"The prevalence of obesity and diabetes is growing at a rapid rate, so the more we know about what factors impact these conditions, the better chance we have for doing something about it," Dr. Chen said. Looking at the effects of H. pylori on HbA1c, and whether the association differs according to BMI status, provided what could be a key piece of information for future treatment of diabetes, she explained.

Type II diabetes causes an estimated 3.8 million adult deaths globally. There have been conflicting reports about the association between H. pylori infection and type II diabetes. To better understand the relationship between H. pylori and the disease, Dr. Chen and Martin J. Blaser, MD, the Frederick H. King Professor of Internal Medicine and professor of microbiology, analyzed data from participants in two National Health and Nutrition Surveys (NHANES III and NHANES 1999-2000) to assess the association between H. pylori and levels of HbA1c.

"Obesity is an established risk factor for diabetes and it is known that high BMI is associated with elevated HbA1c. Separately, the presence of H. pylori is also associated with elevated HbA1c," said Dr. Blaser, who has studied the bacteria for more than 20 years. "We hypothesized that having both high BMI and the presence of H. pylori would have a synergistic effect, increasing HbA1c even more than the sum of the individual effect of either risk factor alone. We now know that this is true."

H. pylori lives in the mucous layer lining the stomach where it persists for decades. It is acquired usually before the age of 10, and is transmitted mainly in families. Dr. Blaser's previous studies have confirmed the bacterium's link to stomach cancer and elucidated genes associated with its virulence, particularly a gene called cagA.

Regarding H. pylori's association with elevated HbA1c, Drs. Chen and Blaser believe the bacterium may affect the levels of two stomach hormones that help regulate blood glucose, and they suggest that eradicating H. pylori using antibiotics in some older obese individuals could be beneficial.

More research will be needed to evaluate the health effects of H. pylori and its eradication among different age groups and in relation to obesity status, the authors noted.

"If future studies confirm our finding, it may be beneficial for individuals at risk for diabetes to be tested for the presence of H. pylori and, depending on the individual's risk factor profile" Dr. Chen.

In an accompanying editorial in The Journal of Infectious Diseases, Dani Cohen, PhD, of Tel Aviv University in Israel, pointed out that while previous studies have addressed the association between type II diabetes and H. pylori in small samples, this study analyzed two independent large national samples of the general population. Dr. Cohen agreed with the study authors, suggesting that adults infected with H. pylori with higher BMI levels, even if asymptomatic, may need anti-H. pylori therapy to control or prevent type II diabetes. If the study findings are confirmed, Dr. Cohen wrote, they "could have important clinical and public health implications."

Popular Science articles about Earth and Climate

Past in monsoon changes linked to major shifts in Indian civilizations
A fundamental shift in the Indian monsoon has occurred over the last few millennia, from a steady humid monsoon that favored lush vegetation to extended periods of drought, reports a new study led by researchers at the Woods Hole Oceanographic Institution (WHOI). The study has implications for our understanding of the monsoon’s response to climate change. The Indian peninsula sustains over a billion people, yet it lies at the same latitude as the Sahara Desert. Without a monsoon, most of India would be dry and uninhabitable. The ability to predict the timing and amount of the next year’s monsoon is vital, yet even our knowledge of the monsoon’s past variability remains incomplete.

One key to this understanding lies in the core monsoon zone (CMZ) – a region in the central part of India that is a very sensitive indicator of the monsoon throughout the India peninsula.

“If you know what’s happening there, you know more or less what’s happening in the rest of India,” said Camilo Ponton, a student in the MIT-WHOI Joint Program in Oceanography and lead author of the study recently published in Geophysical Research Letters entitled "Holocene Aridification of India". “Our biggest problem has been a lack of evidence from this region to extend the short, existing records.”

The study was designed by WHOI geologist Liviu Giosan and geochemist Tim Eglinton, now at ETH in Zurich, and makes use of a sediment core collected by the National Gas Hydrate Program of India in 2006. Sailing around India aboard the drilling vessel JOIDES Resolution for several months, Giosan enlisted colleagues from India and US to help with the project. Extracted from a “sweet spot” in the Bay of Bengal where the Godavari River drains the central Indian peninsula and over which monsoon winds carry most of the precipitation, the core has provided the basis for a 10,000-year reconstruction of climate in the Indian peninsula’s CMZ .

“We are fortunate to have this core from close to the river mouth, where it accumulates sediment very fast,” said Ponton. “Every centimeter of sediment contains 10 to 20 years’ worth of information. So it gives us the advantage of high temporal resolution to address the problems.”

When put together, the research tells the story of growing aridity in India, enables valuable insights into the impact of the monsoon on past cultures, and points scientists toward a way to model future monsoons.

To assemble the 10,000-year record, the team looked to both what the land and the ocean could tell them. Contained within the sediment core’s layers are microscopic compounds from the trees, grasses, and shrubs that lived in the region and remnants of plankton fossils from the ocean.

“The geochemical analyses of the leaf waxes tell a simple story,” said Giosan. “About 10,000 years ago to about 4500 ago, the Godavari River drained mostly terrain that had humidity-loving plants. Stepwise changes starting at around 4,000 years ago and again after 1,700 years ago changed the flora toward aridity-adapted plants. That tells us that central India – the core monsoon zone – became drier.”

Analyses of the plankton fossils support the story reconstructed from plant remains and reveal a record of unprecedented spikes and troughs in the Bay of Bengal’s salinity – becoming saltier during drought periods and fresher when water from the monsoon filled the river and rained into the Bay. Similar drought periods have been documented in shorter records from tree rings and cave stalagmites within India lending further support to this interpretation.

With a picture emerging of changes in the ancient flora of India, Giosan tapped archaeobotanist Dorian Fuller’s interest.

“What the new paleo-climatic information makes clear is that the shift towards more arid conditions around 4,000 years ago corresponds to the time when agricultural populations expanded and settled village life began,” says Fuller of the Institute of Archaeology, University College London. “Arid-adapted food production is an old cultural tradition in the region, with cultivation of drought-tolerant millets and soil-restoring bean species. There may be lessons to learn here, as these drought-tolerant agricultural traditions have eroded over the past century, with shift towards more water and chemical intensive forms of modern agriculture.”

Together, the geological record and the archaeological evidence tell a story of the possible fate of India’s earliest civilizations. Cultural changes occurred across the Indian subcontinent as the climate became more arid after ~4,000 years. In the already dry Indus basin, the urban Harappan civilization failed to adapt to even harsher conditions and slowly collapsed. But aridity favored an increase in sophistication in the central and south India where tropical forest decreased in extent and people began to settle and do more agriculture. Human resourcefulness proved again crucial in the rapid proliferation of rain-collecting water tanks across the Indian peninsula, just as the long series of droughts settled in over the last 1,700 years.

What can this record tell us about future Indian monsoons? According to Ponton, “How the monsoon will behave in the future is highly controversial. Our research provides clues for modeling and that could help determine whether the monsoon will increase or decrease with global warming.”

The study found that the type of monsoon and its droughts are a function of the Northern Hemisphere’s incoming solar radiation – or “insolation.” Every year, the band of heavy rain known as the Inter-Tropical Convergence Zone, or ITCZ, moves north over India.

“We found that when the Asian continent is least heated by the sun, the northward movement of the rain appears to hesitate between the Equator and Asia, bringing less rain to the north,” said Giosan. “The fact that long droughts have not occurred over the last 100 years or so, as humans started to heat up the planet, but did occur earlier, suggest that we changed the entire monsoon game, and may have inadvertently made it more stable!”

Popular Science articles about Astronomy & Space

A half-billion stars and galaxies from NASA's WISE mission revealed -- many for first time
NASA unveiled a new atlas and catalog of the entire infrared sky today showing more than a half billion stars, galaxies and other objects captured by the Wide-field Infrared Survey Explorer (WISE) mission. "Today, WISE delivers the fruit of 14 years of effort to the astronomical community," said Edward Wright, WISE principal investigator at UCLA, who first began working on the mission with other team members in 1998.

WISE launched Dec. 14, 2009, and mapped the entire sky in 2010 with vastly better sensitivity than its predecessors. It collected more than 2.7 million images taken at four infrared wavelengths of light, capturing everything from nearby asteroids to distant galaxies. Since then, the team has been processing more than 15 trillion bytes of returned data. A preliminary release of WISE data, covering the first half of the sky surveyed, was made last April.

The WISE catalog of the entire sky meets the mission's fundamental objective. The individual WISE exposures have been combined into an atlas of more than 18,000 images covering the sky and a catalog listing the infrared properties of more than 560 million individual objects found in the images. Most of the objects are stars and galaxies, with roughly equal numbers of each. Many of them have never been seen before.

WISE observations have led to numerous discoveries, including the elusive, coolest class of stars. Astronomers hunted for these failed stars, called "Y-dwarfs," for more than a decade. Because they have been cooling since their formation, they don't shine in visible light and could not be spotted until WISE mapped the sky with its infrared vision.

WISE also took a poll of near-Earth asteroids, finding there are significantly fewer mid-size objects than previously thought. It also determined NASA has found more than 90 percent of the largest near-Earth asteroids.

Other discoveries were unexpected. WISE found the first known "Trojan" asteroid to share the same orbital path around the sun as Earth. One of the images released today shows a surprising view of an "echo" of infrared light surrounding an exploded star. The echo was etched in the clouds of gas and dust when the flash of light from the supernova explosion heated surrounding clouds. At least 100 papers on the results from the WISE survey already have been published. More discoveries are expected now that astronomers have access to the whole sky as seen by the spacecraft.

"With the release of the all-sky catalog and atlas, WISE joins the pantheon of great sky surveys that have led to many remarkable discoveries about the universe," said Roc Cutri, who leads the WISE data processing and archiving effort at the Infrared and Processing Analysis Center at the California Institute of Technology in Pasadena. "It will be exciting and rewarding to see the innovative ways the science and educational communities will use WISE in their studies now that they have the data at their fingertips."

NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif., manages and operates WISE for NASA's Science Mission Directorate in Washington. The mission was competitively selected under NASA's Explorers Program, which is managed by NASA's Goddard Space Flight Center in Greenbelt, Md. The science instrument was built by the Space Dynamics Laboratory in Logan, Utah, and the spacecraft was built by Ball Aerospace and Technologies Corp., in Boulder, Colo. Science operations, data processing and archiving take place at the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena. Caltech manages JPL for NASA.

Giant squids' giant eyes: The better to see hungry whales with

It's no surprise that giant and colossal squid are big, but it's their eyes that are the real standouts when it comes to size, with diameters measuring two or three times that of any other animal. Now, researchers reporting online on March 15 in Current Biology, a Cell Press publication, have used complex computations to explain those massive peepers. Giant squids' 10-inch eyes allow them to see very large and hungry sperm whales from a distance in the pitch darkness of their deep-sea home. According to the researchers' calculations, animals living underwater would have no use for such large eyes if the goal were to see an average object, such as prey smaller than themselves. That's why even the eyes of large whales aren't much more than 3.5 inches across.

"For seeing in dim light, a large eye is better than a small eye, simply because it picks up more light," said Dan-Eric Nilsson of Lund University. "But for animals that live in the sea or in lakes, the optical properties of water will severely restrict how far away things can be seen.

"Through complex computations we have found that for animals living in water, it does not pay to make eyes much bigger than an orange. Making eyes larger than that will only marginally improve vision, but eyes are expensive to build and maintain."

For Nilsson's team, that begged the question of why giant squid bother with their giant eyes. Using a mathematical model of underwater vision, they tested the benefits of very large eyes for a broad range of tasks under various light conditions. Those efforts showed that very large eyes aren't much better than smaller ones unless one wants to see something that is itself very big, like a whale.

Giant squid may also be unique in that they are powerful enough to escape a sperm whale once they've spotted one, Nilsson says. But how can giant squid see a sperm whale at depths beyond daylight's reach?

"The answer is bioluminescence -- light produced by small gelatinous animals when they are disturbed by the whale moving through the water," Nilsson says. "It is well known that bioluminescence can reveal submarines at night, and diving sperm whales will become visible for the same reason."

The findings may also explain the large eyes of prehistoric ichthyosaurs, giant marine reptiles that looked something like dolphins, the researchers say. Although ichthyosaurs lived long before whales came along, they would have had to contend with giant predatory pliosaurs.

Teenagers scoop science awards

A trio of Britain's brightest youngsters have scooped top honours in science and engineering at the 2012 National Science & Engineering Competition.

Two Cardiff teenagers were voted Young Engineers of the Year for creating a portable device to monitor when mothers are about to go into labour. A third teenager from West Kirby carried off the title of UK Young Scientist of the Year for pioneering work to target specific cancer cells.

The trio, all aged 17, were chosen from a line up of among 360 talented youngsters all with potentially world-beating ideas.

They were singled out by a panel of world-class judges which included Dr Maggie Aderin-Pocock, Nobel Prize-winning biochemist Sir Tim Hunt, and the Science Museum's inventor in residence Mark Champkins.

Wasim Miah and Jessica Jones, from St David's College, Cardiff, South Wales, were named Young Engineers of the Year. The pair impressed with a mechanical and electrical device called the Contraction Optical Monitoring System, which measures foetal contraction intensity. It provides mothers-to-be with a simple indication of when they are about to go into labour, avoiding the traditional mad dash to hospital.

"This is such a massive honour. It feels so strange and I can't believe that we've actually won," a jubilant Jessica said. "The competition was so fierce. I can't believe I'm the first girl to win the UK Young Engineer of the Year, it makes the achievement all the more amazing."

Co-winner Wasim added: "This is absolutely brilliant but we're both still shell shocked. We didn't even tell anyone that we'd entered the competition because we didn't think we would be nominated. We thought we would get some useful contacts to help develop the project so to win is an amazing bonus."

Kirtana Vallabhaneni said she was overwhelmed at being crowned UK Young Scientist of the Year. She has been involved in groundbreaking work helping to identify the harmful cells that cause pancreatic cancer. The aim of the project is to isolate cells in the pancreas that can be targeted with chemotherapy rather than subjecting the whole body to the treatment.

"Everything that I've worked for over the last year has come together. I'm so happy," she said.

The finals took place at The Big Bang UK Young Scientists & Engineers Fair, the country's largest celebration of science and engineering for young people, at The NEC, Birmingham, and prizes were awarded by Minister for Universities and Science David Willetts.