Nature » Jellyfish http://www.pbs.org/wnet/nature The premiere natural history program on television. Thu, 13 Jun 2013 21:31:06 +0000 http://wordpress.org/?v=2.8.4 en hourly 1 The Dirt: This Week in Nature (September 15-21) http://www.pbs.org/wnet/nature/inside-nature/the-dirt-this-week-in-nature-september-15-21/7805/ http://www.pbs.org/wnet/nature/inside-nature/the-dirt-this-week-in-nature-september-15-21/7805/#comments Fri, 21 Sep 2012 16:15:25 +0000 fultonk http://www.pbs.org/wnet/nature/?p=7805

  • Thirty-Something Killer Whales Still Benefit From Mom.

    Even when they have reached 30 years of age, male killer whales that still have a menopausal mother nearby have a greatly increased chance of survival compared to those without mothers. Some scientists believe that longevity in post-reproductive whale mothers is a genetic advantage that increases the odds that the longer living female will pass her genes onto more grandchildren. A similar theory supports the evolution of menopause in human females and other primates. Why young males need mom’s attention more than daughters is answered by whale social dynamics. Females giving birth are supported by their own family’s group, so that it makes more sense for a grandmother whale to invest her protective resources into her son.

    More at Discovery.

  • Colorful Monkey New to Science.

    Image by Flickr user teresehart via Creative Commons

    Image by Flickr user teresehart via Creative Commons

    In the central region of the Democratic Republic of the Congo, villagers are familiar with a colorful monkey that is new to science. Locally called a “lesula,” the monkey has a strikingly blond beard, dark limbs, reddish colored tail and back and brilliantly blue buttocks. It also has an eerily human face. DNA tests confirm that it is a genetically distinct species. Since it lives in mostly inaccessible jungle areas, it is not presently at risk to human hunting, but the increasing incursions of bush-meat hunters in the area could mean an uncertain future.

    More at New York Times.

  • To Bee or Not to Bee: Epigenetics Involved in Beehive Roles.

    It was not long ago that DNA was considered the sole determinant of behavior in animals. Today, the emerging field of epigenetics is discovering many ways in which environmental chemicals influence DNA through a process called DNA methylation. At the Institute for Basic Biomedical Sciences Center for Epigenetics, Andy Feinberg and colleagues tested the chemical changes that occur in the DNA of bees that switch roles from nurses to foragers. These job changes occur within a hive when there is shortage of one or the other. Suspecting that an epigenetic chemical message directs the bees to their new assignment, the DNA methylation of bees before and after the switch was compared. As suspected, many DNA regions believed to be involved in hive job assignments showed distinct methylation changes in bees that made the job transition.

    More at Red Orbit.

  • Encounter With a Giant Jellyfish.

    Jellyfish are no friends of swimmers and their painful stings are no laughing matter. However, in Russia’s White Sea, there exists a giant among jellyfish — the lion’s mane jellyfish. As described by New Scientist reporter Douglas Heaven, the lion’s mane can measure 70 centimeters in width and have tentacles that are 15 meters long—making it difficult for swimmers to keep their distance. Fortunately, although the lion’s mane sting is extremely painful, it usually is not lethal.

  • Eucalypt Tree Preserve May Be Largest in the World.

    Dr. Dean Nicolle grew up in Australia with an unusual childhood passion: eucalypt trees. But unlike most childhood interests, Dr. Nicolle followed his vision into adulthood. He became a botanist and travelled throughout the Australian continent collecting eucalypt specimens. The results is an arboretum with a collection of 7,000 trees representing 800 different species of eucalypt.

    More at ABC News.

  • Elephant Slaughter in Africa Fueled By Religious Demand in Asia.

    A black market in ivory religious carvings has set up the worst slaughter of African elephants in decades. In an article from National Geographic, it appears that just about every religion opens a market for ivory in some Asian country. Even worse, in some places, and again for religious reasons, “new ivory” is in greater demand than “old ivory.” And while the forces driving the commercial value of ivory already easily outmatch the efforts of conservationists, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, which is supposed to limit the trade of ivory, has implemented policies that have actually made the situation worse.

  • 390 Million-Year-Old Mollusk Meets a 3-D Printer.

    3-D printers allow scientists to recreate actual models from two dimensional images by “printing” multiple layers of a soft plastic material that then hardens. That technology was recently used to model the reconstructed fossil of a spiky mollusk that lived 390 million years ago. Using computer imaging software to reconstruct the likely original shape of the mollusk, the team then used the 3-D printer to create a working model that was 12 times the size of the original.

    Animation showing how a CT scan was used to recreate the spines and plate structure of a 390 million year old fossil mollusk, a multiplacaphoran:

    More at National Geographic.

  • Snake Origins Traced Through Genetics.

    Researchers at the Department of Ecology and Evolution at Stony Brook University have used a “massive molecular dataset” derived from 44 genes and 161 species of lizards and snakes to trace these species back in time. One of the surprising results so far is the suggestion that all snakes evolved from an ancient line of subterranean snakes. Apparently, in the evolution of modern snakes, a transition was ultimately made from subterranean to surface life.

    More at Science Daily.

  • Tabbys and Cheetahs Share Same Gene.

    Image by Flickr user Ullisan via Creative Commons.

    Image by Flickr user Ullisan via Creative Commons.

    Whether its a tabby domestic cat and cheetahs share a common gene that gives them their respective spotted or striped coat. Actually, there are at least two genes that control whether the feline will have spots or stripes and whether they will be blotched or distinct. This new field of discovery is possible because scientists now have a complete feline genome available. The DNA samples used in the study were of feral domestic cats in California and both wild and captive cheetahs from South Africa and Namibia.

    More at New York Times.

  • Our Reptile Hearts.

    The human heart has a complex system for inducing the electrical current that causes it to rhythmically beat. A very similar system is present in the hearts of birds. Spongy tissue is responsible for this function in mammals and birds, and there has been research to determine whether or not its forerunners appeared in genetically-distant reptiles. Now, new research has finally located that same spongy tissue hidden behind a thin wall of tissue in the hearts of reptiles. The finding squares with our understanding of the evolution of the heart from reptile to birds and mammals. The research also may have an important practical application. The human fetal heart relates in some ways to the same spongy tissue present in adult reptiles and understanding it better could be important in treating prenatal heart disorders.

    More at Science Daily.

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

    ]]>     http://www.pbs.org/wnet/nature/inside-nature/the-dirt-this-week-in-nature-september-15-21/7805/feed/ 0     Oceans in Glass: Behind the Scenes of the Monterey Bay Aquarium: Introduction http://www.pbs.org/wnet/nature/episodes/oceans-in-glass-behind-the-scenes-of-the-monterey-bay-aquarium/introduction/636/ http://www.pbs.org/wnet/nature/episodes/oceans-in-glass-behind-the-scenes-of-the-monterey-bay-aquarium/introduction/636/#comments Mon, 20 Jun 2011 15:17:05 +0000 admin http://www.pbs.org/wnet/nature/2008/06/24/overview-8/ NATURE reveals the secrets of underwater magic in Oceans in Glass: Behind the Scenes of the Monterey Bay Aquarium.

    Imagine standing on the bottom of the ocean and looking up into a glittering kelp forest alive with darting fish, or watching five-foot-long sharks and giant tuna whiz by at arm’s length, or being surrounded by elegant, lacy white jellyfish as they soar, pulsing, through the water. Visitors to the Monterey Bay Aquarium on the coast of Northern California experience all this… and more.

    For more than 20 years, the Monterey Bay Aquarium has entertained, educated, and fascinated its nearly 2 million annual visitors with pioneering displays of realistic undersea environments. Now NATURE gives viewers a behind-the-scenes look at one of the world’s leading centers for marine research and conservation — a marvel of engineering and biology that, literally, captures Oceans in Glass. Buy the DVD. Online content for Oceans in Glass was originally posted January 2006.

    ]]>     http://www.pbs.org/wnet/nature/episodes/oceans-in-glass-behind-the-scenes-of-the-monterey-bay-aquarium/introduction/636/feed/ 68     Under Antarctic Ice: Antarctic Research http://www.pbs.org/wnet/nature/episodes/under-antarctic-ice/antarctic-research/5108/ http://www.pbs.org/wnet/nature/episodes/under-antarctic-ice/antarctic-research/5108/#comments Sun, 19 May 2002 18:45:53 +0000 diana cofresi http://www.pbs.org/wnet/nature/?p=5108

    In 1997, “Under Antarctic Ice” filmmaker Norbert Wu journeyed to Antarctica for the first time on a special grant from the National Science Foundation (NSF), the U.S. government’s leading funder of scientific research on the frozen continent. But the United States isn’t alone in conducting research in Antarctica. Currently, 17 other nations — from Russia and China to Brazil and Uruguay — also operate Antarctic research centers. And each year, thousands of scientists (and even a few filmmakers) get to visit these remarkable laboratories, and conduct studies focused on everything from the world’s climate to the land mass locked beneath the ice.

    Antarctica has long been a magnet for scientists due to its size, location, weather, and isolation from the rest of world. It is among the most pristine places on earth, making it a perfect spot to study how pollutants travel through the atmosphere. Sadly, polar researchers have found that even deadly toxins, such as mercury, can travel vast distances and end up in Antarctic snow, plants, and animals. And in the 1980s, they realized that chlorine compounds routinely used in aerosol sprays, air conditioners and other products were carried to Antarctic skies, where they ate a hole in the protective ozone layer, letting in dangerous ultraviolet light. Such studies led directly to an international agreement to reduce the use of ozone-eating compounds.

    Today, Antarctica is a key outpost for global warming studies. Cores taken from its thick ice sheet hold tiny air bubbles that have allowed scientists to track the historical buildup of the global warming gas carbon dioxide, formed by burning fossil fuels. In essence, the cores are time capsules that reach back thousands of years, to a time when there was less carbon dioxide in our skies. And the continent’s massive sea ice sheets may act as an early warning system for warming’s arrival: Some scientists say the recent collapse of several major sheets signals the beginning of a potentially dangerous warming period. Water locked in polar ice, for instance, could be released, helping raise sea levels and flood coastal cities.

    Antarctica is also among the darkest places on earth, with its inky winters lasting nearly half the year, making it ideal for astronomers. They have built state-of-the-art telescopes that sweep the skies for celestial objects created at the birth of our universe. Antarctica’s location at the bottom of the globe also means it sits at a perfect place to study Earth’s gravitational and magnetic fields, making it a haven for astrophysicists. And in the future, the polar ice may help provide a kind of shield for a deep-buried instrument designed to spot neutrinos, mysterious high-energy particles produced by the exploding stars and other objects. Scientists want to bury the instrument, dubbed “Ice Cube,” so that the ice helps sift out unwanted atomic particles. The ice also holds amazing meteorites, including some that started life as rocks on the surface of Mars.

    Marine biologists love Antarctica because its seas are filled with remarkable but poorly understood creatures, from fish and crustaceans that make their own anti-freeze to whales and seals that travel thousands of miles in search of food. And on land, researchers are amazed by the ability of some plants and animals to survive the harsh conditions. There is even a huge underground lake locked thousands of feet beneath the ice, called Lake Vostock, that scientists believe may hold specially adapted life forms found nowhere else on earth. They are trying to design a special probe that could drill and melt its way into the lake and collect water samples without contaminating it with bacteria or pollutants from the outside world.

    Scientists also value Antarctica because it is a land without borders. Under an international treaty, Antarctica is open to all, and scientific findings are shared. Many projects are multinational, and a visit to any base is often an experience in multiculturalism, with scientists from around the world sharing common quarters.

    Of course, getting there isn’t easy. While many of the bases are perched on the continent’s edge, and can be reached by icebreaking ships in the right season, others are inland, sometimes right at the South Pole itself. In places, travel can require special aircraft equipped with skis, helicopters, and rugged snow buggies that crawl across the ice on tank treads. While traffic may be sparse, the drivers still have to be careful, because you never know when a crevasse may appear before your vehicle and threaten to swallow it whole. And even minor breakdowns can be life-threatening if you aren’t prepared for the weather.

    Still, most scientists relish the opportunity to work in Antarctica. A hardy few even stay throughout the winter, spending months in near-total darkness, cut off from supply flights. The scientific rewards, they say, are well worth the sacrifice.

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