The Dirt: This Week in Nature (6/23-6/29)

  1. Lichen Survive in Outer Space.

    One theory about the origin of life on earth is that primitive living organisms traveled through space from other planets, perhaps hitching a ride on asteroids, and then crash-landed on earth. Called panspermia, this theory has always been vulnerable to the fact that the harsh conditions in outer space might be too hostile for life to survive. An experiment aboard the international space station between 2008 and 2009 seems to lend some support to the panspermia theory because it established just how tough life can be. Various organisms were exposed to outer space, including tremendously extreme temperature variations, direct exposure to the sun’s radiation, and cosmic radiation. The organisms in general did much better than expected. Lichen especially proved resistant and when returned to earth grew normally again. Although the experiment does not provide direct evidence of panspermia, it does cast doubt on one of the perceived obstacles to the inter-planetary exchange of primitive life.

    More at Science Daily.

  2. Ugly Dog Contest.

    We’ve bred them to come in all shapes and sizes; some are cute and some are … well, not so much. The annual ugly dog contest in Petaluma, California this year had some exceptional entries. Which is your favorite?

  3. Endocrine Disruptive Pesticide Might Be Banned.

    The pesticide Atrazine has been known to cause reversal in the gender of affected male frogs.

    The pesticide Atrazine has been known to cause reversal in the gender of affected male frogs.

    It is called Atrazine and it is responsible for innumerable animal deaths since its widespread use began. The chemical interferes with the endocrine system of animals and has been known to cause reversal in the gender of affected male frogs. The pesticide is used on a great variety of crops and some 80 million pounds of it are applied each year in the United States. It easily enters the atmosphere, does not degrade quickly, and is carried by snow and rain to places far from its origin. There is also some evidence that it is carcinogenic in humans. The European Union banned the stuff in 2004 and now the United States government might follow suit. The Environmental Protection Agency recently held an open meeting on the chemical and environmentalists are awaiting its decision.

    More at Treehugger.

  4. Slow, Steady, Sneaky Sharks.

    At half the speed of most sharks, the Greenland shark might seem a laggard. But don’t tell that to the seals of the Norwegian arctic. Based upon stomach contents, it appears that the Greenland shark has the ability to sneak up upon snoozing seals. In this area, the seals sleep in the water … a habit that may have developed to avoid their biggest predator: polar bears. In order to catch a Greenland shark in the midst of a sneak attack, researchers intend to set up video monitors on the back of some of the sharks.

    More at National Geographic.

  5. California Condor Advocates Try to Get the Lead Out.

    In 1982 there were only 22 California condors left. Nearly extinct, a coordinated effort was undertaken to save the bird. Today, the population has recovered and now numbers about 400 individuals. But the condor faces a new threat from an unlikely source. Because they feed on carrion, condors often consume meat from animals that were shot by hunters’ lead bullets. The ingestion of lead by the condors has had a devastating effect upon the population — some dead birds have shown blood lead levels many times that of a lethal amount. Lead bullet use within the condors’ range was banned in 2007, but the law appears to have been ignored by some hunters and that has rendered it ineffective.

    More at Red Orbit.

  6. The Genetics of Dolphin Brains.

    Although still in its infancy, the search for the genetic clues to brain development in animals has revealed some tantalizing clues about the dolphin’s brain. Humans, Elephants and Dolphins are known for their large brains. It seems that a particular gene common to all three allows for a slower metabolism, which is necessary for large complex brains to operate. The genes associated with human intellect disorders are also found in dolphins — a hint that the same gene is involved in higher cognitive function. Another gene, involved in controlling sleep, is common to humans and dolphins, although it is slightly altered in dolphins possibly because they have evolved a method of putting only half of their brain to sleep. As reported by Discovery News, Lori Marino, a senior lecturer in neuroscience and behavioral biology at Emory University said that “if we use relative brain size as a metric of ‘intelligence’ then one would have to conclude that dolphins are second in intelligence to modern humans.”

  7. New Dinosaur Bird Ancestor Found.

    The Buenos Aires’ Argentine Museum of Natural Sciences is presenting a new dinosaur skeleton which provides a major link between modern birds and their dinosaur ancestors. The specimen is about 10 feet long. It dates back 90 million years ago and when alive was likely covered in feathers.

    More at Fox News Latino.

  8. Nature’s Masons.

    The New York Times reports on a tiny sea creature that is responsible for some of the significant structural features of our planet. Forams comprise some 6,000 different species of single cell organisms. Once they die, their shells become compressed into rock, such as limestone, and that in turn has been used in construction since ancient times. Forams are also useful for telling geological time. In fact, it was the sudden disappearance of forams from rock layers that led to the discovery of the asteroid impact that caused the great extinction of the Cretaceous period. Forams also are vital for locking up carbon dioxide. Planktonic forams absorb 25% of the carbon dioxide produce each year in the earth’s oceans. But even forams seems unable to keep up with the rate of acidification of the oceans and their shells are reportedly significantly thinner today than they were before the industrial revolution began.

    Forams comprise some 6,000 different species of single cell organisms. Credit: OCC Biology Department - Marc Perkins (Via Flickr Creative Commons)

    Forams comprise some 6,000 different species of single cell organisms. Credit: OCC Biology Department - Marc Perkins (Via Flickr Creative Commons)

  9. Keeping a Wary Eye on Bird Flu.

    People who come into close contact with fowl that are infected with the virus known as bird flu can themselves become fatally ill. What really concerns scientists, however, is the possibility that bird flu will genetically mutate and become transmissible from person to person. The probability of the right mutations occurring spontaneously are the subject of much debate. On the one hand, viruses mutate at an astoundingly fast rate. On the other, it takes a very specific combination of mutations for the disease to become transmissible between mammals. But it has happened before. The infamous 1918 flu pandemic that killed millions worldwide probably occurred because of a similar mutation in a virus. Meanwhile, scientist watch and wait and hope that the probability of a deleterious mutation in bird flu is at the highest limits of prediction.

    More at the New York Times.

  10. Cave Dweller DNA Isolated.

    After sequencing Neanderthal DNA, scientists now have a usable sample of the DNA of 7,000-year-old fossils of two cave dwellers who lived in what is now Spain. The socalled “iceman,” named Otzi, was a mere 5,300 years old when its mitochondrial DNA was recovered. So far, analysis suggests that the Spanish cave dwellers were not genetically related to the present occupants of Spain. Instead, the new specimens bear a closer relation to the DNA of Northern Europeans. More revelations are probably in store as the complete genome of the new additions are untangled.

    More at Live Science.

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