Science News Headlines . Did the chicken descend from the dinosaur? . There's life in the salty desert sands of New Mexico . Do singing birds need an audience? . Does blood become too stale to use even if carefully preserved? . Drug tests for athletes . For these flies, sugar is the stuff of life . Jelly fish boom time: as ocean waters are warming, jelly fish are blooming in large numbers. But perhaps not. The chicken and the dinosaur Scientists have confirmed a close relationship between mastodons (the pre-historic elephant-like animals) and elephants, which is not a surprise. However, they are still piecing together the proof that today's chicken is descended from the mighty Tyrannosaurus rex (T. rex) dinosaur. Recently, scientists have discovered some new evidence for this theory. Scientists gather information about extinct animals (ones that died out a long time ago) by studying their fossil remains. The fossils are mostly the skeletons of the creatures, that have often been well-preserved. There is usually no information about soft flesh or skin which would have decayed long since. So scientists have to make educated guesses about how the animal looked and how its bones were held together. Also, they have to find out how it walked and whether it could climb trees or fly. Such fossil studies have shown that modern birds have similar skeletons to that of the T. rex. So for a long time, scientists thought that birds must be descended from the T. rex. Now, scientists have managed to find bits of protein from connective tissues in a T. rex fossil. This confirms their relationship to birds, including chickens and ostriches. This is the first time that evidence beyond bone has been used to make such a prediction. In fact, this is the first molecular evidence for this relationship. This is because the team from Harvard University in the U.S. has extracted collagen from the muscle of a T. rex and showed that it matched the collagen of chickens. The dinosaur protein was obtained from a fossil found in 2003 in the U.S. It took two years to find that soft tissue was preserved without decay in this specimen. The team hopes to also prove that T. rex lies on the evolutionary tree between alligators and chickens and ostriches. This means that they came after alligators and before chickens. It also appears to fit better into the modern bird family than the reptile family (of alligators and lizards). The salt of life It's hard to believe today, but millions of years ago the dusty New Mexico desert in the U.S. was covered by a shimmering ocean. That ocean water evaporated long ago. But it left behind huge deposits of salt. Some of those salt deposits contain tiny pockets of trapped ancient ocean water. These super salty deposits tell us about a long ago time before even dinosaurs ever walked on Earth. Now, a team of scientists has found the oldest-known biological (living) molecules inside some of those briny salt-water pockets. The team analyzed samples of salt mined deep underground in southeastern New Mexico. They found molecules of cellulose -- the tough, fibre-like molecule that makes up plant cell walls. Algae and some bacteria also make cellulose. Because the molecule is made by living organisms (whether by plants or bacteria), its presence in the salt deposit is evidence that some kind of ancient organism made the cellulose that was trapped inside. The crysalline salt deposits are dated to be 253 million years old. They contained cellulose in a tiny mat-shape made up of very fine threads. Each cellulose fibre is much much smaller than a human hair, with a width of 5-15 nanometers (just the thickness of about 50 atoms). These fibres are shown in the picture, as they appear when seen through a microscope. To identify the cellulose molecules, the scientists removed material from inside the salt-water pockets. They placed the material in a hot solution of two chemicals, sodium hydroxide and sodium borohydride. This harsh solution dissolves all known biological materials except cellulose. The material didn't dissolve, telling the scientists that the material in the salt deposits was most likely cellulose. As an additional step, the researchers also mixed the material with a cellulose-digesting enzyme. This time, the material quickly dissolved. Taken together, these results give strong support to the scientists' conclusion that the salt-water pockets contain cellulose. Buried deep below Earth's surface, the cellulose molecules inside the salt are protected from the sun's harmful ultraviolet radiation and other harsh conditions. Such salt-water pockets might be ideal places for preserving ancient molecules, which are signs of early life. These evidences are hard to find since most biological molecules break down or decay on exposure to the natural elements (wind, water, sunlight). Scientists in a field called astrobiology are especially interested in these old cellulose molecules. Astrobiology is the study of life in the universe. Many astrobiologists focus on finding the best ways to search for life on other planets, aiming to answer questions about life in space -- Does it exist now, and did it ever exist in the past? It's a good question, and one that's hard to answer. After all, where would you start looking on Mars if you wanted to look for signs of life? As it turns out, both Mars and Jupiter's moon Europa once had oceans -- just like the New Mexico desert. Do they have similar salt deposits? No one knows for sure. But if planets and moons do, they might give scientists a good target to look for signs of past life. Listening to Birdsong A male zebra finch (shown in the picture) changes his song when singing to a female in ways that people can barely detect. But the female finch can tell the difference, according to a new study. In fact, the study also indicates that the female prefers the song and special trills when the male sings especially for her. Scientists had noticed slight variations in the songs of male zebra finches based on whether they were singing alone or whether there was a female (and potential mate) nearby. With an audience, the males increased the pace of their songs and controlled the notes they used. The new study focussed attention on the listening females, which have not been well studied in the past. The scientists, who study the ecology and evolution of animal behavior, set up a long cage with a sound speaker at each end. One broadcast the sound of a male zebra finch singing to himself, like someone singing in the shower. The other speaker broadcast a male performing for a female audience, as if he was giving a concert. Female birds were placed between the two speakers. Some of the birds had mates, others didn't. The females shifted around a bit, and then most of them hopped over to sit beside just one speaker. All the birds that made a clear choice liked songs meant for a female audience, even if they'd never met the male. Mated females also had a chance to listen to two different performance songs, one from an unknown male, and one from their mate. They spent more time listening to the concert version of their mates' songs. This suggests that after a while, females learn to recognize---and prefer---the songs of their mates. Scientists then studied the brains of the females. They found certain areas of the brain perked up when the birds listened to the concert songs. These brain areas may be involved in recognizing and evaluating the songs, and storing the memories of them. This research deals with the field called directed communication, when the communicator, or sender, focuses the message for a specific audience. One example is the way moms speak to their babies. Mothers around the world use the same sort of high-pitched sing-song chatter, and the babies respond best to those sounds. Songbirds are one of the only other species known to learn their communication, in this case their songs. Studying how they communicate and respond might help us learn more about our own communication. Blood Goes Stale -- and Fairly Quickly After an accident, an ambulance arrives and rushes a patient to the hospital. Doctors realize the patient has lost too much blood and needs a donation of stored blood, called a transfusion. That blood comes from people who have voluntarily donated their own for emergencies or surgeries, so it's ready when needed. But how long can blood be safely stored before it's no longer any good? Today, the government says hospitals can hold it for 42 days before it's considered too old. The average age of blood used in transfusions is about 15 days. But new research shows even 15-day-old blood might be past its prime. Blood performs a crucial role in our bodies. The red blood cells in blood transport oxygen to cells. In fact, blood not only carries nutrients to cells but also carries away waste from those cells. Previous research has shown that blood changes while it is in storage. But no studies had tested whether these changes affect the people who receive the blood. In a new study, scientists in the U.S. examined hospital records of 6,002 people who received a transfusion of red blood cells after heart surgery. Almost half of the patients had been given new blood, less than 14 days old, and a little more than half had received blood older than 2 weeks. The scientists tracked the health records of the patients to check for any other differences. Scientists found significant differences in the recovery rate of the two sets of people: the people who received fresh blood recovered better. This could be because of the ageing factor so that the chemical that allows for oxygen exchange may no longer be efficient. In addition, it was found that the shape of the blood cells itself had changed. This could also cause the difference, by making it difficult for the flattened blood cells to pass through smaller capillaries. The scientists caution that more studies are necessary before we can tell for sure how long blood can be stored. But surely studies such as this one will help those patients receive the healthiest blood possible. Foul Play? The International Olympics are coming up soon. Cricket fever has just passed. All over the world, athletes are participating in increasingly competitive games and sports. Drug testing in sports has become a serious matter. Athletes train hard to build muscle and body strength. But some resort to cheating. They can do this by abusing drugs called steroids to build extra muscle. This practice is not only unhealthy, but it also gives an athlete an unfair advantage. That's why most professional sports test for it and ban players who are guilty of using these drugs. New studies show that some athletes who use body-enhancing drugs may have a specific gene variation. This variation is such that even if they take banned drugs, it will not show up in the tests! On the other hand, athletes who have not taken the drugs may show a reaction to it, again, because of their gene type. Why does this happen? Genes provide a chemical blueprint for making proteins. Proteins not only build the cells in your body, but they also carry out all the different jobs that cells do. People generally have two copies of each gene in their bodies---one copy comes from the mother and the other comes from the father. Sometimes, one or even both copies of the gene are defective or missing. In such cases, a person may produce far less of the protein than the average person does. That's what happens in this case. Most banned steroids used by athletes (called anabolic steroids) are made of testosterone. Testosterone is naturally made in the body by both men and women, though it is primarily known as a male sex hormone. Testosterone can spur muscle growth. When testosterone is processed by the body, a chemical called TG is made. In the study, the scientists found about 15 percent of 145 healthy males who were tested lacked an enzyme called UGT2B17 entirely. Just over half the men had one copy of the gene that makes the enzyme, and one-third of them had two copies. The men were given a single shot of testosterone, enough to show up in doping tests. The researchers then monitored the production of TG in the men's urine for the next 15 days. About 40 % of the men who lacked the enzyme did not produce TG and so the test showed negative, although they had indeed taken the drug. So such people can easily cheat the system. Worse, still, the test was also carried out on people who were not given any testosterone at all. The study showed that 14 % of people with two copies of the gene made so much TG that the test showed positive. That means, they would be branded as cheats even if they never cheated! Scientists say the new study must be taken seriously by people and associations who perform the standard drug tests. They suggest that drug testing must be combined with genetic testing to really get to the truth. Sugary Survival Skill Dehydration dooms most animals. Humans, for example, have about 80% water but die if their bodies lose just about lose about 12 percent of it. But one bug is different. The larvae of an African fly known as Polypedilum vanderplanki live in the bottom of rain puddles in the African desert. When the dry season hits, and their habitats dry up, they can endure an almost complete loss of body water. They curl up to a small 4 mm size and stay in a state very close to deep sleep, for up to 17 years. Just add water, and before long the dead-looking flies are moving and feeding again! Biologists have known for years that a sugar called trehalose plays a role in the drought-survival tactics of these species. Trehalose keeps the cells from falling apart by turning into a glassy state. This state is much like melted table sugar that has solidified into hard candy drops. Trehalose is uniformly distributed throughout P. vanderplanki's bodies. Trehalose sugars bond with the cells' outer layer or membrane. This protected the cells' insides from extreme distortion during dehydration. Scientists want to see if this dehydration technique could eventually be used to preserve entire organs. Jellyfish Boom Jelly fish is a transparent, umbrella shaped fish that has special stinging cells. Jelly fish use their sting to paralyse their prey before eating them. So if you touch a jelly fish, it can sting you and you can get an itchy rash. Many jelly fish can also glow when you touch them. In recent years, jelly fish have started appearing in places that don't usually have so many. And they are appearing in large numbers, and are not welcome there! For instance, fishing people are catching lots of jelly fish rather than fish in their nets. Also, pipes that bring in water as coolants in nuclear power plants are getting clogged by jelly fish stuck inside them. The giant jellyfish is found in the seas around Japan. They are upto 2 ms across (bigger than a human) and weigh more than 200 kg! Fishermen say that instead of catching one or two giant jellyfish in a week, they sometimes catch more than 1,000 in one net. Sometimes the nets get damaged; sometimes, the other, edible, fish that have been caught get eaten up by the jelly fish. Scientists have found that when sea water suddenly gets warmer, it causes a change in the jellyfish lifecycle. It helps the young jelly fish to grow faster. Also, there is a powerful ocean current called the Tsushima Current that flows off the coasts of Korea, China and Japan. This helps to carry the baby jelly fish more than 2,500 kilometers into the Sea of Japan. This current has strengthened in recent years. It usually helps fishermen by bringing a lot of eidble fish, such as horse mackerel. Now fishermen and scientists are watching and waiting to see if the currents will bring more jelly fish than fish. Off the coast of Alaska, however, the long-tentacled jelly fish in the Bering Sea started booming about 10 years ago. But as the Bering sea began to warm, the amount of plankton in it dropped. Since jelly fish eat plankton, there was now not enough food for them. So the number of jelly fish in the Bering sea is steadily declining. Humans are changing the environment in many ways that might lead to more jellyfish. More and more power plants are being built, which often warm the waters nearby. More fish farms are being built, which can add a lot of nutrients to waters. This can lead to more plankton and more food for jelly fish. There may be fewer jellyfish in places like the Bering Sea, but there now may be more in other parts of the oceans. Today, scientists still have more questions than answers about what is causing the changes in jellyfish numbers around the world. But through their studies, researchers hope to find out more about what is causing the change in the growth of the jellyfish. More importantly, they want to find out if this can tell us anything about the health of the oceans. Adapted from various News Agencies salt.jpg>