From: Kathleen M. Wong, California Academy of Sciences
Published November 26, 2004 12:00 AM

Earliest Human-Ape Ancestor Found and Other Stories

Earliest Human-Ape Ancestor Found


The earliest common ancestor of modern humans and apes found to date has been unearthed in Spain. At 13 million years old, Pierolapithecus catalunicus appeared just after lesser apes such as gibbons went down a separate evolutionary path from orangutans, gorillas, chimpanzees, and humans. Salvador Moya Sola of Barcelona's Paleontology Institute and colleagues discovered the fossil outside of Barcelona. They pieced together 87 bone fragments from what was probably an adult male weighing approximately 75 pounds. They report in the journal Science that the creature is a blend of features from both earlier primates and modern apes. Its flattened chest, stiff lower spine and wrist structure resembles apes more than monkeys. These features suggest it spent a lot of time climbing upright in trees. On the ground, it probably knuckle-walked like modern chimpanzees. However, it lacked the proportionately larger hands of modern great apes. The location of the fossil supports the increasingly accepted idea that modern great apes evolved primarily in Eurasia.


Ocean Survey Reveals Weird New Species, Long Migrations


The Census of Marine Life, the most comprehensive survey of the world's oceans so far, has released a progress report showing just how little we know about the oceans. The decade-long survey, which began in 2000, involves hundreds of scientists from 70 countries. By trawling ocean waters, the scientists have found a total of 38,000 new species since the study's inception. These included on average about two new fish species a week in 2004, but also thousands of microbes, which make up an estimated 90 percent of the biomass of the oceans. The more colorful discoveries include a striped goby from Guam, and an eight-inch-long purple burrowing worm from the mid-Atlantic. Attaching satellite tags to turtles, tuna, and other migrating creatures has revealed they probably crisscross the vast Pacific basin several times during their lives. Other studies suggest the presence of circulation gyres just 10 kilometers in diameter and thousands of meters below the surface. These seem to contain surprisingly high concentrations of sea life.


Humans Have Altered Half The Amazon


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Nearly half of the Brazilian Amazon is occupied by humans, according to a new study. This figure is three times greater than the 16 percent of the jungle that Brazil's government says is occupied. The environmental group Imazon used satellite data to track altered jungle acreage. They found that the forest is fast succumbing to logging, ranching, farming, and human habitation. The rate of deforestation last year was the second highest recorded, and affected an area larger than New Jersey. The Brazilian Amazon hosts up to a third of all known plant and animal species and contains about ten percent of the world's fresh water. The settled areas include an "arc of deforestation" that stretches across the southern half of the forest. The group called for more nature reserves that would encompass 2/3 of the existing jungle. The world's largest rainforest, the Amazon covers an area even larger than the continental United States.


Fight Global Warming--Save A Sardine


A lack of sardines can push greenhouse gas levels over the oceans out of whack. The new study, published in the journal Ecology Letters, suggests restoring sardine populations could help prevent global warming. The connection lies in the sardines' diet. The fish wolf down mass quantities of phytoplankton, microscopic marine plants. When not consumed, dead phytoplankton sinks to the ocean floor and rots, releasing greenhouse gases. Andrew Bakun of the University of Miami, Florida, and Scarla Weeks of the University of Cape Town, South Africa, studied ocean workings off Namibia, where sardine numbers plummeted in the 1970s due to overfishing. They found that the area produces far more eruptions of noxious greenhouse gases now than before the sardine bust. The gases include the rotten-egg fumes of hydrogen sulfide, a chemical that depletes oxygen from water and is a source of oceanic "dead zones" in places such as the Gulf of Mexico. Methane, a far stronger greenhouse gas than carbon dioxide, is also a byproduct. Global warming should only worsen the problem as currents pull more nutrients to the surface, fueling more plankton blooms.


The Physics Of Walking On Water


Basilisk lizards bear the nickname "Jesus lizards" because they can run on water. Now scientists have deciphered how such a hefty creature maintains its miraculous form of locomotion without sinking. To measure the forces at work during the lizard's two-legged run, Tonia Hsieh of Harvard University added silvery reflective particles to the water in a long, tracklike tank. She then filmed a number of Basiliscus plumifrons racing across the surface. She reports in the Proceedings of the National Academy of Sciences that the lizards are able to generate a perfect balance of lateral and downward forces. When the lizards slap their wide, tassel-toed feet downward, they generate sufficient upward force to avoid sinking. But the lizard also falls forward with every step like a human runner on sand. To avoid falling on its face, the lizard also generates powerful sideways forces with each step, allowing it to maintain an upright posture on the water.


World's Largest Crater Field Found In Egypt


Beneath the shifting sands of the southern Egyptian desert lies the most widespread meteor crater field ever found. The discovery may help scientists refine their understanding of the impact history of other planets. Philippe Paillou of Bordeaux University Observatory, France, and colleagues spotted the circular depressions using orbital imaging radar. The crater field ranges across 1,750 square miles. The structures are up to 260 feet deep, and up to 7.8 miles across. Closer examination of 13 of the craters suggest the field happened relatively recently, about 50 million years ago. The immense size of the field and the distribution of its craters shows it was the result of multiple meteor impacts, not one large meteor that split into many pieces. The site is one of only nine impact fields discovered to date on Earth. Erosion by wind and rain tends to erase crater traces on this planet quickly. By contrast, planets such as Mars are littered with meteor impact evidence. The finding helps validate the use of orbital imaging radar to detect such crater fields on other planets.


Related Links


Earliest Human-Ape Ancestor Found: San Francisco Chronicle / New York Times / news@nature
Ocean Survey Reveals Weird New Species, Long Migrations: Yahoo Daily News (Reuters) / BBC
Humans Have Altered Half The Amazon: Yahoo Daily News (Reuters)
Fight Global Warming--Save A Sardine: New York Times
The Physics Of Walking On Water: BBC
World's Largest Crater Field Found In Egypt: Discovery.com


Source: California Academy of Sciences


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