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The Dirt: This Week in Nature (November 24-30)

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  1. How Old Is the Grand Canyon?

    New estimates of the age of the Grand Canyon come from the University of Colorado Boulder and the California Institute of Technology. It turns out that even the dinosaurs might have enjoyed the view. It is now estimated that the Grand Canyon was formed some 70 million years ago.

    More at Red Orbit.

    Photo by Flickr user Markusnl via Creative Commons

    Photo by Flickr user Markusnl via Creative Commons

  2. The Life and Rebirth of the Benjamin Button Jellyfish.

    In a remarkable story about a little know jellyfish, Nathaniel Rich writes for the New York Times about how one small creature attained a form of immortality. Known to scientists as Turritopsis dohrnii, the tiny jellyfish has an amazing life cycle. Instead of dying of old age, its genetic machinery allows it to reverse its age — it literally goes from an adult to a type of fetus from which it then grows back into a new adult. It is as if a chicken grew old and became an egg and then hatched into a new chicken. Of course, the most immediate question raised by the study of this creature is what can it teach humans about possible immortality. As the article explains, however, the road to that answer has not even been charted let alone paved.

  3. Pilot Whales Dance to Danger.

    Not everyone is a fan of olympic synchronized swimming, but researchers have found that pilot whales in the Strait of Gibraltar use the technique to warn each other of danger. When boats approach an area where the pilot whales are present they begin to synchronize their swimming in response. The whales also stayed below the surface for longer periods when boats were nearby, a sign that their natural rhythms were affected by human activity. This is detrimental to the remaining 300 pilot whales in the area since it means that they have less time to feed and tend to their young. The synchronized swimming behavior does not appear to be a learned response to the busy waters of the Strait of Gibraltar. The pilot whales of Canada also swim rhythmically when disturbed by humans.

    More at phys.org.

  4. Australia Once Home To Huge Marsupials.

    Fifteen million years ago, Australia had large rainforests. Taking advantage of the bountiful trees that grew in these rainforests were large marsupials, some relagated to land weighing as much as 3 tons and standing some 13 feet tall. Fossils found in Australian “vertical caves” allowed scientists to reconstruct the likely body type to one such marsupial, Nimbadon lavarackorum. The strong forelimbs, claws and mobile joints of this creature suggest strong similarities to the koala and is strong evidence that like koalas, Nimbadon was adapted to life in the trees.

    More at Live Science.

  5. Astronauts Find New Species.

    One of the skills that astronauts are expected to master is to be able to spot interesting geological features and even new life forms. The astronauts who are associated with the International Space Station, were training in a cave in Sardinia, Italy, when they completely exceeded the expectations of the training course. In one of the caves, they discovered a small aquatic crustacean that is new to science. Normally, this family of crustaceans, also known as woodlice, are land-based creatures. However, these new woodlice have evolved to become aquatic like their ancestors.

    More at phys.org.

  6. Watermelon Genome Sequenced.

    An international team of geneticists have sequenced the watermelon genome. Watermelons are believed to have originated in Africa and first cultivated by the ancient Egyptians. Today, China is the leader is watermelon cultivation while the United States is fourth and as many as 40 nations are significantly involved in the watermelon industry. So far, the 23,440 genes of the watermelon (around as many as human beings) has revealed that some of the genes for disease resistance seem to have been lost during the process of human cultivation. Bringing back these natural genes will be goal for the future.

    More at phys.org.

  7. In Kenya, De-Tusking Elephants in a Last Ditch Effort to Save Them.

    Organized gangs of poachers, some well financed by organized crime and armed with automatic weapons, are decimating the elephant population in Kenya at an unprecedented rate. The poachers sometimes hunt at night by moonlight. The bounty, the elephants tusks, are a lucrative cash crop for Asian, especially Chinese, black markets. In order to stop poachers, the Kenyan government is turning to a controversial technique — preemptively removing the tusks from some of the older, great-tusked elephants. In a story reported by CBS news, one such bull elephant, Mountain Bull, has been shot numerous times by poachers but so far has escaped. He was recently captured by Kenyan veterinarians who tranquilized him and removed part of his tusks to reduce his desirability to poachers.

    More at CBS.

  8. Beware of Holiday Fragrances.

    The holiday season is here and it’s time for giving and buying. Retailers will do almost anything to put you into a buying mood, so it should come as no surprise that science is being enlisted in that effort. Apparently, one of the more subtle strategies to separate the shopper from his money is to use certain aromas. Scientists at the Washington State University College of Business have done extensive research and have come across a common, but uncommonly effective, scent that seems to increase retail spending — the smell or oranges. In some experiments 20% more money was spent in stores where a simple orange fragrance was released. So, the moral of this story is the if you smell oranges in your favorite shopping place, think caveat emptor.

    More at Treehugger.

  9. New Species of African Lion.

    It is not unusual that new species of insects or other small creatures are found — but a new species of lion? DNA tests done on the lions at the Addis Ababa Zoo in Ethiopia have demonstrated that the lions there, known for their spectacular large, dark flowing manes, are actually a distinct species of African lion. This population of lions originated with 7 lions captured in in Ethiopia in 1948 that were used to populate the zoo. Their numbers have now increased to 15. Scientists are now trying to determine if any similar lions are still in the wild or if this collection represents the last members of what they now believe to be a nearly extinct species of lion.

    More at Mother Nature News.

  10. Even Grasshoppers Struggle With Urban Din.

    Experimenters at Bielefeld University in Germany studied the mating calls of bowwinged grasshoppers under two different conditions. The first group were country dwellers who lived in relatively quiet habitats. The second group lived nearby roadsides with abundant traffic noise. When a female grasshopper was placed near each of the test subjects, the urbanized insects exhibited significantly louder lower frequency chirping than their country kin. Special instruments are needed to measure the grasshoppers’ full range of frequencies, but scientists believed that other insects also modulate their sound production in response to human-made background noise.

    More at National Geographic.

“The Dirt: This Week in Nature” curated and written by Robert Raciti.

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