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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.
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Colorful Monkey New to Science.
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.
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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.
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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.
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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.
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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.
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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.
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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.
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Tabbys and Cheetahs Share Same Gene.
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.
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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.