-
Want to Lose Weight? Cultivate the Right Bacteria.
It is becoming more obvious to the medical community that the billions of bacteria that line our intestines are also determined in part by genetics. By luck of the draw, some people have the type of bacteria that are tremendously efficient at utilizing every last calorie. Others have species of bacteria that are less efficient and waste more nutrients. If you’re in the former category you will probably put on the pounds faster than those with the less efficient bacteria. It is so far unclear how much genetics and environment each contribute to who gets which and whether interventions short of bariatric surgery can permanently change the bacterial population balance for individuals.
-
Flying Frogs.
The ability to fly, or at least glide, must have distinct survival advantages since it developed independently in so many animals. In Malaysia and Borneo, Wallace’s frog, named for British scientist Alfred Russel Wallace in the 19th century, has developed the ability to parachute out of the trees it calls home and glide for as much as 50 feet to another tree or even onto the ground. The frog has oversized webbing between its toes which give it aerodynamic lift and thick foot pads to give it a soft landing.
-
Robots Mimic Ants.
With only a few hundred thousands neurons for a brain, it is hard to understand how individual ants act collectively to find the shortest path to their nests and accomplish other tasks that would seem to require much more intelligence. Scientists believe the ants use simple local rules to navigate. For example, when an ant comes to a fork in the road it follows the pheromones left by its peers, but it also is programmed to take the path that deviates the least from the path it was following to the nest. Using sugar-cube sized robots that follow trails of light left by other robots, scientists have noticed that these robots, too, eventually “learn” to take the path of least divergence in completing a maze. Complex behavior arising from simple rules is an important concept that has application for problems as diverse as computer communication and long distance trucking routes.
-
After 17 Years Underground, They’re Coming Again.
Coming in swarms of biblical proportions, Magicicada septendecim, otherwise known as the cicada insect, is about to emerge again on the east coast. Different broods of cicadas hibernate underground for either 13 or 17 years and then reemerge, en masse, in the millions as part of a bizarre life cycle. The east coast brood, known as brood 2, covers an area from Connecticut to North Carolina. Last awaking in 1996, they are scheduled to take over trees everywhere in their range as soon as the ground temperature reaches 64 degree Fahrenheit. Millions of cicadas have been known to take over a single acre of land. And if you’re wondering how nature came by the 13 and 17 year intervals think prime numbers. One theory suggests that mathematically, parasites with two-year life cycles would not be able to infect the 17 year cicada more than twice a century.
-
Invasive Species Hide in Ships’ Ballast.
It’s an ideal situation for stowaways. Ocean going commercial vessels fill their ballast tanks in one far-flung port and empty them in another. Along for the ride are any number of hitchhiking creatures that enter the ship along with its ballast water. It was just such a mechanism that allowed comb jellyfish from North America to invade the Black Sea and cause a cataclysmic decline in native marine life there. It would seem that a United Nations treaty requiring all international vessels to treat their ballast water would be a reasonable solution. So far, however, the United Nations has declined to act and even powerful countries such as the United States have done little to address the issue.
-
An Aerial Killing Machine.
Hundreds of millions of years worth of success has honed the dragonfly into an expert aerial hunter. With a hunting success rate of around 95%, the dragonfly puts to shame other predators many of which fail as often as they succeed in bringing down their prey. The amazing ability of a dragonfly to zero in on its flying target, predict the target’s future path and then intercept it and eat it in midair is orchestrated by a relatively small but dedicated number of neurons that direct a 360 degree visual system. Entomologists are not alone in their fascination with dragonflies. Military experts would love to duplicate the dragonfly’s targeting and interception abilities.
-
The Greening of Lake Erie.
Large parts of Lake Erie are turning green, a situation that spells major problems for the local ecology. The problem is a primitive life form called cyanobacteria, also known as blue-green algae. The ultimate cause is a change in local agricultural practices. Farmers now fertilize earlier, and with greater amounts of fertilizer#&8212;a practice that almost insures that extra fertilizer runoff will find its way into the lake. Once the fertilizers make their way into Lake Erie, the cyanobacteria feast and multiply. In the process, the decaying bacterial organisms deplete the lake of oxygen and release toxins, both of which in turn kills fish and other aquatic life. Dead zones, areas where no life exists, will result. If there is any good news it is that agricultural practices can quickly change and eventually reverse the damage.
-
How Geckos Get a Grip.
Duplicating the stickiness of gecko feet has been an aspirational goal for applied science looking for a better adhesive under wet conditions. In a study of the tiny hairs that give the gecko its excellent velcro-like grip, scientists have noted that the grip depends on the “wettability” of the surface upon which the grip is maintained. Surfaces such as glass have a high wettability index and therefore even gecko grips are weakened on them. On the other hand, hydrophobic surfaces, such as waxy leaves and tree bark, allow a firm grip even when covered with water, such as during a tropical forest downpour.
-
This Sea Lion Really Rocks.
At the Long Marine Lab at the University of California, Santa Cruz, Ronan, a three-year-old sea lion has proven her ability to bob her head with the beat of various music. Previously, only humans and birds were known to have the ability to keep a beat. However, Ronan can change her moves to suit apparently any beat and demonstrates this in the video. Enjoy.
-
The Call is Out to Save a Most Unusual Bird.
An American bird known as the Gunnison sagegrouse may be the most endangered bird species in the country. It was discovered only 13 years ago but only an estimated 5,000 animals exist today in a limited range in Colorado. The male bird’s unusual courting ritual involves inflatable yellow chest sacs that make popping noises while the bird struts its flamboyant spiny tail feathers. Now the race is on to see whether the bird will become extinct before it makes it through the red tape and delay required to become a classified endangered species.
More at Discovery News.
“The Dirt: This Week in Nature” curated and written by Robert Raciti.