ScienceShots: May 2006

• Gotta be me. Why do populations remain diverse? According some evolutionary theorists, it's because oddballs often enjoy advantages over their run-of-the-mill mates. A study of wild guppies now supports that idea. Biologists collected guppies from puddles in a forest in Trinidad and then redistributed them so that each puddle contained a small minority of males with color patterns very different from the rest. Sure enough, those outsiders were more likely to survive the next 2 weeks, the researchers report 31 May in Nature. They propose that predators, such as the killifish, may focus on the dominant color patterns and overlook the exceptions. (Photo: K. Hughes / U. Illinois)
• Feels Delicious. When a mole encounters an insect in the soil, it snaps it up immediately. But how do the blind rodents tell an ant from an acorn? The answer may lie with a honeycomb-shaped patch of cells, called Eimer's organ, that lies along the edge of the nose. The purpose of the cells has puzzled scientists since the 1800s, but a clue comes from mole behavior: The rodents tap their noses on unfamiliar objects. Now, the first in-depth microscopic study of the organ, published 29 May in Proceedings of the National Academy of Sciences, reveals it to be packed with mechanosensory nerves like an ultrasensitive fingertip. So moles may live by the simple rule, if it feels good, eat it. (Photo: Ken Catania / Vanderbilt )
• Fire in the deep. Even though three-quarters of the planet's volcanic activity occurs below the ocean's surface, few people have ever witnessed it directly. But in 2004 and 2005, U.S. National Oceanic and Atmospheric Administration scientists used remotely operated vehicles to videotape two eruptions occurring along the Mariana Arc in the western Pacific. Unlike the brief, steady flows of superheated gas seen at other hydrothermal vents, the volcanic plumes lasted for days and shot out molten sulfur, ash, and small stones in bursts, the researchers report 25 May in Nature. The team also found a new shrimp species among other hearty creatures that seem to be able to survive the eruptions. (Photo: NOAA Vents Program)
• Star warps. Just as a glass of water bends sunlight, the massive gravity of a galaxy cluster can warp the glow from a super-bright quasar. The phenomenon--called gravitational lensing--is clearly seen in this Hubble Space Telescope photo, released on 23 May. Here, the lensing has caused a single quasar to appear as five stars in the center, including one red version seemingly embedded in the cluster's heart--the first time such a quintuply-lensed quasar has been observed. Look closely, and you can also see triple images of a single galaxy, likewise multiplied by the cluster. (Credit: ESA/NASA/Tel Aviv University/Caltech)
• Wrapped up tight. Venom is the weapon of choice for most spiders, but some prefer a satisfying "crunch." Philoponella vicina wraps its prey in hundreds of meters of silk to make a crushing shroud, researchers report in the May issue of Naturwissenschaften. Tension in the silk threads delivers a force many times the spider's own weight, enough to break legs and collapse compound eyes. The study is the first to show that wrapping can damage or even kill prey, instead of merely immobilizing it. Lacking poison to finish the job, Philoponella regurgitates digestive fluid into the shroud, creating a self-contained liquid meal.(Photo: Julin Weng)
• Survival sushi. The site of a condor munching on a whale carcass seems a peculiar harbinger of good news, but that's precisely what it is according to conservation biologists. After the near-extinction of the California condor in the 20th century, scientists wondered whether birds hatched in zoos would know how to survive in the wild. This image--captured last week near Point Sur, California--is another indication that the condors are on the rebound. And they're picking up where their ancestors left off: In the late Pleistocene, condors are thought to have survived extinction by feeding on marine mammals. (Photo: Ventana Wildlife Society)
• Comet cascade. New images of the ongoing self-destruction of Comet Schwassmann-Wachmann 3 are giving astronomers their best view yet of how the solar system's fragile "icy dirtballs" break up. This view from NASA's Spitzer Space Telescope, released 10 May, shows a few dozen house-sized fragments within a long trail of debris. Spitzer's infrared vision can detect mere specks as well, and that will reveal whether most of the comet's mass has disintegrated into dust and vapor, as some scientists believe. Skywatchers in the northern hemisphere can see the doomed comet with binoculars for 2 weeks starting 12 May, but its closest approach to Earth will be a safe 12 million kilometers. (Photo: NASA/W. Reach (SSC/California Institute of Technology))
• Blitzkrieg. Squishy as they are, jellyfish can be as destructive as a bullet when hungry. They must shoot their stinging cells at crustaceans with enough power to puncture the animals' shells. Normal high speed cameras aren't fast enough to catch the strike, so researchers used an ultra-high speed camera, which captures 1.4 million frames per second. The resulting Kodak moments revealed that the stinging cells discharge in 700 nanoseconds, reach an acceleration of 5.4 million g, and strike with the force of some bullets. The lightening assault--which may be driven by a release of energy from stored collagen in the stinging cells' walls--is one of the fastest movements in the animal kingdom, the team reports 8 May in Current Biology. (Photo: Timm Nüchter)
• Little sucker. Adult hearts pump blood into arteries by contracting, and then they relax their valves and vessels to suck in more blood from veins. In the embryonic heart, however, it seemed that this valveless tube simply squeezed blood from one end to another. But a new imaging study shows that embryo hearts are suckers too. Thanks to the translucency of zebrafish embryos, scientists watched blood sloshing through the tiny hearts like this one, its muscle tissue stained in blue. Cells at one end of the tube squeezed together, unleashing a wave that hit the tube’s rigid exit and bounced back. The waves converge to enlarge the heart’s far end and allow suction to pull blood through the tube, researchers report 5 May in Science. The upshot: The sucking action of adult hearts has its roots very early in development. (Image: A Forouhar et al./Science)

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