Roundup of Recent Science Discoveries, 1999
Ancestor of Mammals Discovered
The fossil skull of a 260-million-year-old sheep-sized animal was found near Williston on the Northern Cape, South Africa. It is the most primitive member yet discovered of a group of plant-eaters on the evolutionary line to mammals. Called Anomodonts, they were the dominant land creatures during the Permian period, long before the dinosaurs appeared on Earth.
The new species was named Anomocephalus africanus, which means “Lawless-headed one of Africa.” The name makes reference to the fact that characteristics common to the Anomodont group were not uniform throughout all its members. Before this discovery, it was thought that Anomodonts and other creatures associated with the group known as therapsids, or mammal-like reptiles, originated in Russia. The new find has reinforced the idea that the distant ancestors of mammals might actually have come from South Africa.
An Antigravity Contraption?
NASA researchers are attempting to validate a controversial gravity modification experiment that Russian scientist Eugene Podklentov conducted several years ago. Podklentov claimed to have shielded objects from Earth's gravitational pull by the use of a ceramic superconductor disc spinning in a magnetic field. He reported that samples of non-conducting and nonmagnetic objects suspended over the rotating disc lost up to 2% of their gravitational pull. Although the gravitational shielding effect of Podklentov's achievement was weak, it is still significant, and its effect may prove to be cumulative for a stack of superconductive discs. If researchers could develop a device that would manipulate gravity waves, it would have a tremendous economic impact on space launches and other forms of transportation.
Fish-Eating Dinosaur Found
A new species of a predatory dinosaur was discovered in the Sahara by an international team led by Paul Sereno of the University of Chicago. The new species, tenerensis, was excavated in the Tenere desert of Niger and named Suchomimus tenerensis (“crocodile mimic from Tenere”). Souchos is Greek for crocodile.
The 100-million-year-old skeleton measures 36 feet in length and is 12 feet at the hip. Its skull has an extremely long and narrow snout with large teeth near its end, similar to that of specialized fish-eating crocodiles. The jaws are studded with over 100 conical teeth that functioned like hooks rather than sliding blades. The huge two-legged creature's powerful forearms were used to snare fish and other prey as it waded in rivers.
Suchomimus belongs to a peculiar group of fish-eating predators called Spinosaurids (Spiny Lizards) that grew to the size of Tyrannosaurus.
A Collision Split Earth and Moon
Analysis of data from the Lunar Prospector spacecraft supports the theory, first proposed in the Apollo era, that the bulk of the Moon was ripped away from early Earth when an object the size of Mars collided with it. Similarities in the mineral composition of Earth and the Moon indicate that they share a common origin. In the past, some had interpreted this finding to indicate that Earth and the Moon had formed separately from the same cloud of rocks and dust. But new data shows that the Moon has a small core that contains less than 4% of the Moon's total mass, whereas Earth's iron core contains approximately 30% of the planet's mass. If Earth and the Moon had simply formed from the same cloud of rocks and dust, the Moon would have a core similar in proportion to Earth's. A more likely synopsis is that a large body struck Earth, forcing an ejection of rocky, iron-poor material from the outer shell into orbit, which collected to form the Moon.
According to researchers at Princess of Wales Hospital, Bridgend, Wales, Lucilia sericata, the larvae of the common greenbottle fly, could help to address the problem of antibiotic resistance. Over the past three years, the clinical use of such maggots has been reintroduced into the UK and elsewhere (to well over 400 centers) with considerable success.
Maggots clean wounds by eating only the dead or dying tissue, thus promoting nature's healing process. (Some other fly species do eat healthy flesh.) The mechanism by which the larvae kill bacteria in wounds are not fully understood, but among the explanations offered are the production of natural antibiotic-like agents, the modification of the pH of the wound, or the ingestion and destruction of bacteria as part of the normal feeding process.
Many patients receive this anachronistic larval treatment as a last resort when conventional treatments, including antibiotics, have failed. The research did conclude. however, that using maggots earlier in combating infection may often avert the need for antibiotics.
“S” Marks the Solar Storm
After analyzing daily images taken by the Japanese Yohkoh (“sunbeam”) spacecraft over a two-year period, NASA-sponsored scientists have discovered that an S-shaped structure called a sigmoid often appears on the Sun in advance of a coronal mass ejection. Coronal mass ejections (CMEs) are violent discharges of electrically charged gas from the Sun's corona, or outer atmosphere, that are as powerful as billions of nuclear explosions.
The largest explosions in the solar system, CMEs hurl up to 10 billion tons of gas into space at speeds of one to two million miles an hour. The outbursts occur several times in a day, but only those shot toward Earth are dangerous. The solar blasts travel the 93 million miles between the Sun and Earth in about four days and can damage satellites, disrupt communications networks, and cause power outages. The new findings may give space weather forecasters a reliable tool to predict approaching solar storms before they erupt.
It's All in Your Head
A University of Iowa study found new evidence that people may be shy or outgoing because of the way their brains are structured. Researchers at IU used PET scans to study the brain activity of their subjects. The PET scans revealed that introverts have more activity in the frontal lobes of the brain and anterior, or front, thalamus. These areas are activated when a person's brain takes on internal processing such as remembering, problem solving, and planning. Extroverts exhibit more activity in the anterior cingulate gyrus, temporal lobes, and posterior thalamus. These areas are typically thought to be more involved in sensory processing such as listening, watching, or driving.
Differences in cognitive style and sensory-processing relate to characteristics associated with introversion and extroversion. True introverts are quiet, inwardly focused, and reclusive. Extroverts are gregarious, socially active, and sensation seeking. Introverts get more of their stimulation internally, whereas extroverts seek outside sources. These variations in brain activity suggest that a lot of our individual differences have an underlying biological cause.
Brightest Gamma Burst Ever Seen
On Jan. 23, 1999, astronomers saw visible light emitted from a gamma-ray burst. Previously, only the faint, fading afterglow of the event had been detected. Although the catastrophic explosion (called GRB 990123 for the day it occurred) was 9 billion light-years away, the light from it was so bright that observers on Earth could have seen it in the night sky with a pair of binoculars. It was the brightest burst seen so far.
Gamma-ray bursts are brief emissions of high-energy photons traveling to Earth from violent explosions in the deepest reaches of space and typically last a few seconds. The amount of energy released from a gamma-ray burst boggles the mind. Exploding with the power of ten million billion suns, only collisions between objects like super-dense neutron stars and black holes have enough energy potential to create such a cataclysmic event. No one is sure what causes a gamma-ray burst.
Fantastic Inca Mummy Find
In March 1999, an international archeological team found the frozen mummies of two girls and a boy, who had been killed in an Inca sacrificial ritual. Buried about 500 years ago under 5 feet of rock and earth, their remains are in an unprecedented state of preservation and appear as if they just died. CT scans made a few days after the discovery revealed two “perfect mummies” with all their internal organs intact. No cause of death was evident. The American-Peruvian-Argentine-team that made the remarkable find was funded by the National Geographic Society.
The burial platform also contained an elaborate offering to the Inca gods, including some 35 gold, silver, and spondulus shell statues, half of them clothed; moccasins; and exquisite Inca pottery, some of it still containing food. Most of the artifacts are in pristine condition.
The Inca empire once extended 2,500 miles (4,023 kilometers) from Colombia to central Chile, but ended after only nine decades with the Spanish conquest in 1532.
A team of German, Spanish, and American marine scientists studying samples of sediment dredged up off the coast of Walvis Bay, Namibia, discovered the largest bacterium ever seen. Some of the record-size organisms were as large as the period at the end of this sentence (up to 3/4 of a millimeter wide). They feed on sulfide produced in the sea floor and store nitrate from the seawater in a central sac or “anaerobic lung” which they oxidize for energy.
The new bacteria strain shines white because the microscopic sulfur granules stored within them reflect light. Held in strands by a common mucus sheath, they look like a thin string of pearls, which inspired researchers of the Max Planck Institute for Marine Microbiology to name them Thiomargarita namibiensis (Sulfur Pearl of Namibia).
A Washington University anthropologist claims that the characteristics of a 24,500-year-old Neanderthal skeleton of a four-year-old boy show that Neanderthals and early humans cohabited and produced children. If the skeleton is indeed evidence of interbreeding, it contradicts the dominant hypothesis among scientists that Neanderthals were a separate branch of the evolutionary line from early modern humans (Cro-Magnons). According to this theory, early humans were believed to have migrated from Africa and wiped out the Neanderthal population in Europe, either through warfare or because the supposedly more intelligent Cro-Magnons adapted more successfully to their environment.
The child's skeleton was found on a hillside in the Lapedo Valley north of Lisbon, Portugal, in December 1998. It possesses characteristics of both species, such as the stocky trunk and sturdy leg bones of Neanderthals and the prominent jaw and small teeth of modern humans. Radiocarbon dating of the skeleton in 1999 confirmed that the child lived 4,000 years after the arrival of early modern humans (Cro-Magnons) on the Iberian Peninsula where Neanderthals already resided—offering possible evidence that the two groups intermixed, interbred, and produced offspring over several millennia. If this extensive interbreeding did occur, then Neanderthals may not have been a separate species after all. Neanderthals may have disappeared not because they were wiped out from war, but because their traits may have eventually been “bred out.” This would also mean that their human descendants—us—carry a little bit of Neanderthal in our gene pool.
A Freakish Frog Mystery
Since 1995, alarming sightings of large numbers of frogs born with extra limbs, missing eyes, and other bizarre abnormalities have been reported more and more often, raising public fears that these ecologically sensitive amphibians are bellwethers of some larger environmental catastrophe. Speculation about the causes of the frog abnormalities included pesticides, chemical pollution, or DNA damage to frog embryos as a result of too much ultraviolet radiation passing through the thinning ozone layer.
Now researchers have partially answered this puzzle. In April 1999, two studies released by scientists from Hartwick College and the Stanford Center for Conservation Biology provided strong evidence that some of the weird disfigurements are caused by small parasitic flatworms called Riberoria trematodes. These creatures burrow into the hindquarters of tadpoles where they physically rearrange the limb bud cells and thereby interfere with limb development. Although parasite infections appear to be the direct cause of multiple limb deformities, other kinds of abnormalities, including missing or malformed limbs and eyes, may be caused by something other than parasites, and more research is needed before scientists can draw any conclusions.
Rethinking Long-Necked Dinosaurs
The popular conception of giant long-necked dinosaurs eating leaves from treetops like giraffes is probably more fiction than fact according to the latest research. Scientists at Northern Illinois University and the University of Oregon used specially developed computer software to study the bone structure and simulate the neck mobility of Diplodocus and Apatosaurus (formerly known as Brontosaurus). These two long-necked, long-tailed, plant-eating sauropods lived about 120 million years ago during the Jurassic period. Sauropods grew over 130 feet (40 m) long and weighed up to 100 tons. They were the largest animals ever to live on land.
The researchers determined that the necks of both creatures were significantly less limber than traditionally assumed. Diplodocus could barely lift its head higher than its back and Apatosaurs had only a little more flexibility. The study infers that the dinosaurs held their necks horizontally or even curved downward a lot of the time while feeding on water plants, ferns, or low shrubs, and couldn't lift their heads to the vertical position.
Another Menacing Asteroid
Remember the short-lived doomsday asteroid scare of 1997 that turned out to be false? Now there's another one heading our way. Astronomers are cautiously observing the orbits of a potentially hazardous asteroid discovered in January 1999. Researchers at the Minor Planet Center (MPC) have calculated that near-Earth asteroid 1999 AN 10 will pass within 24,000 miles (39,000 kilometers) of Earth in 2027, with the potential for even closer approaches in 2044 and 2048. Six more close flybys of the kilometer-wide rock have been identified, and while astronomers cannot predict all future approaches for more than a few decades after any close encounter, they say that AN 10's orbit will remain dangerously close to the orbit of Earth for the next 600 years. But there's no need to panic. Astronomers advise that its chances of colliding with Earth are very small.
The Mother Lobe of Genius
When Albert Einstein died in 1955 at the age of 76, his brain was removed and preserved for scientific study. Recently, Prof. Sandra F. Witelson and her colleagues at McMaster University, Canada, compared anatomical measurements of Einstein's brain with a control group of men and women whose brains were of normal intelligence, and reported their findings in June 1999.
In general, Einstein's brain was similar to other brains except for one area called the inferior parietal region, which was 15% wider than those of the other brains studied. The inferior parietal lobe is important for processing visual and spatial cognition, mathematical thought, and imagery of movement. The unusual development of this lobe may have been a contributing factor to his genius.
In addition, Einstein's brain was unique in that it did not have a groove, called a sulcus, that normally runs through part of this area. The absence of the groove may have increased his mental power by allowing more neurons in this area to establish connections between each other and work together more easily.