Update: January 23, 2008

HERE’S TO THE BUGS!

By Pam Eastlick for THE DEEP on line

Welcome to The Deep science and technology column where we cover topics from the deep sea to deep space and beyond.

LOOKING SMALL

All the current data have been retrieved from the space-faring robot MESSENGER, and planetary astronomers are looking to do a little revision on our current theories about Mercury, the smallest planet. Mercury is, of course, the smallest planet and the closest one to the Sun and that closeness has made it very difficult to study from Earth. The MESSENGER spacecraft has just performed a very close fly-by of Mercury. This fly-by will be used to help slow the spacecraft down with an eye toward eventually going into orbit around Mercury. There are several mysteries about Mercury. You’d expect it to be hot, so close to the Sun, but since it has no air, it’s also cold, in shadows and on Mercury’s night side. Mercury has the largest temperature variations of any solar system body. But one of the biggest mysteries involves its incredible density and its magnetic field. Planetary geologists suspect that, like Earth, Mercury has an iron core; but unlike Earth, the iron core forms the bulk of Mercury’s interior. How did that happen? No one knows, but scientists are counting on MESSENGER to answer some of those questions. Of course, the new pictures now returning have posed a whole bunch of new questions that we didn’t know enough to ask before. Welcome to the advancement of science! And now we leave the reaches of space, return to Earth and go a little buggy.

AND THE WHAT? SHALL INHERIT THE EARTH?

If the aliens ever do arrive at our little blue planet and look to address its dominant life form, they certainly won’t have any interest in those amusing talking monkeys. The dominant advanced life form on this planet is without question, the insects. They may not be as intelligent as the humans, but there are sure a heck of a lot more of them than there are of us. And there is one form of insect that dominates all the others. The great biologist J.B.S. Haldane is reputed to have answered the question “What is the most important thing you’ve learned in your years of study?” by saying “The Creator has an inordinate fondness for beetles, because he made so many of them.” And indeed there are approximately 350,000 species of beetles on Earth, and probably millions more yet to be discovered. Beetles account for an astounding 25% of all known life forms on the planet. The reason for this large number of beetle species has been debated by scientists for many years, but never resolved. Now a team of scientists has shown that large numbers of modern-day beetle lineages evolved very soon after the first beetles originated, and have persisted ever since. Many modern-day lineages first appeared during the Jurassic period, when the major groups of dinosaurs appeared too. Prior to this study the survival success of beetles was directly linked to the explosion of the flowering plants upon which they feed. This rise of the flowering plants signaled the start of the Cretaceous era some 140 million years ago. However, mapping species numbers onto the evolutionary tree shows that many modern beetle lineages significantly pre-date the appearance of the first flowering plants. Beetles have displayed an exceptional ability to seize new ecological opportunities and develop a great range of life styles and feeding types. Unlike the dinosaurs, which dwindled to extinction, scientists think beetles survived because of their ecological diversity and adaptability. They’ve been around since before the dinosaurs and they far outnumber us in number of species, number of individuals and sheer weight. Taking any bets on who survives in the long haul? And now a little snippet on one of the adaptations that may allow the insects such a leg up (besides the fact that they have four more legs than we do).

BINOCULAR SMELL

Having two eyes allows us to have depth perception and having two ears allows us to pinpoint a noise precisely. Recent research shows that, at least for insects, sensing odors in stereo is equally important. Insects communicate through an invisible world of scents. By exploiting infrared technology, researchers at Rockefeller University have made that world visible. With the ability to see smells, these scientists have discovered when fly larvae detect smells with both their olfactory organs, they find their way toward a scented target more accurately than when they detect the odor with only one olfactory organ. To study this behavior, the scientists had to figure out which direction the larvae move with respect to the source of the odor. But since odors are invisible, the researchers could neither predict how the flies would move in relation to these scents nor guess whether the odors were concentrated in patches or along a gradient. To complicate matters, odors whisk to and fro at the mercy of the slightest stir, making it impossible to determine their concentrations at particular locations. They needed to ‘see’ the smells. The researchers used a novel spectroscopic technique that used infrared light to create environments where they could see, control and precisely quantify the distribution of these smells. When they observed the insects' behavior, they found that although insects with only one functional olfactory organ could sense odors, only the ones with both olfactory organs working accurately navigated toward the odor source. Seeing smells. What a cool idea! And now another story about odors and their uses.

HONEY! YOU SMELL LIKE A . . . .

Body odor is big business in the US and around the world. Untold billions of dollars, yen, euros and virtually every other currency are spent on making us smell better. Soaps, deodorants, colognes and perfumes are all employed to make us smell unlike our actual odor. Virtually all of this odor masking is social in humans but we aren’t the only inhabitants of planet Earth that do this. For many other species, however, the motivation isn’t social; it’s survival. Barbara Clucas, a graduate student in animal behavior at UC Davis, has observed both ground squirrels and rock squirrels applying snake scent to themselves by picking up pieces of shed snakeskin, chewing it and then licking their fur. She discovered that adult female squirrels and juveniles applied snake scent more often than adult males, which are less vulnerable to predation by snakes. The scent probably helps to mask the squirrel's own scent, especially when the animals are asleep in their burrows at night, or to persuade a snake that another snake is in the burrow. Snake-scent application is one of a remarkable package of defenses that squirrels use against rattlesnakes. Researchers have recently learned that squirrels can also heat up their tails to send a warning signal to rattlesnakes, which can "see" in the infrared; assess how dangerous a particular snake is, based on the sound of its rattle; and display assertive behavior against snakes to deter attacks. In addition, some of these squirrels have evolved resistance to snake venom. So the next time you spritz on that expensive cologne, just be grateful it doesn’t have to smell like snake skin! And now our final story, not about how you smell, but what you eat.

CULINARY SHOCKER

Although I’m not sure this is as common among Chamorus as it should be, in the home where I grew up, the mealtime mantra was “Eat Your Vegetables!” My mother and father grew many of the vegetables we ate in our garden, and Mom was convinced that vegetables were the best thing for you. Especially raw vegetables. We ate tomatoes, peppers, lettuce, onions and garlic straight from the garden without them ever going anywhere near a cooking pot. Now, in a finding that defies conventional culinary wisdom, researchers in Italy report that cooking vegetables can preserve or even boost their nutritional value in comparison to their raw counterparts, depending on the cooking method used. Nicoletta Pellegrini and colleagues note that although many people maintain that eating raw vegetables is more nutritious than eating cooked ones, a small but growing number of studies suggest that cooking may actually increase the release of some nutrients. However, scientists are seeking more complete data on the nutritional properties of cooked vegetables, the researchers say.

In the new study, the researchers evaluated the effects of three commonly used Italian cooking practices — boiling, steaming, and frying — on the nutritional content of carrots, zucchini and broccoli. Boiling and steaming maintained the antioxidant compounds of the vegetables, whereas frying caused a significantly higher loss of antioxidants in comparison to the water-based cooking methods. For broccoli, steaming actually increased its content of glucosinolates, a group of plant compounds touted for their cancer-fighting abilities. The findings suggest that it may be possible to select a cooking method for each vegetable that can best preserve or improve its nutritional quality, the researchers say.