Category: Top Posts

How Animals Evolved to Live in Low-Oxygen Locales

By Perrin Ireland | July 9, 2013 2:27 pm

Myoglobin in mammals evolutionThe leisurely pace of a sloth or koala ambling through the forest can certainly seem desirable, but those habitats and lifestyles aren’t for everyone. For the animals tasked with surviving in some of the more extreme environments on earth, such as the oxygen-deprived ocean, or the thin air of the mountaintops, mastery of efficient oxygen uptake is essential.  Several studies that recently appeared in Science shed light on the molecules involved in the abilities of certain animals to push the limits of low-oxygen living.

Animals’ Deep Dive

The fossil record shows that the body shape, limbs, and tails of mammals transitioning from land to water changed drastically to make diving mammals more efficient at hunting, hiding, and surviving in the water. But until last week, scientists didn’t know much about the molecular changes that allowed for these diving behaviors. Scott Mirceta, Michael Berenbrink, and their colleagues at the University of Liverpool have not only determined how it is that modern marine mammals can dive for such long periods, but they’ve also estimated the diving ability of 130 ancestors of today’s elite diving mammals.

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CATEGORIZED UNDER: Living World, Top Posts
MORE ABOUT: mountains, ocean

Honeybees and Dolphins Help Humans Find Lethal Mines

By Perrin Ireland | June 10, 2013 2:28 pm

Dolphins Make Naval History!

Dolphins have uncovered a marvel of naval history: the 125-year-old Howell torpedo, the first torpedo that could be released into the ocean and follow a track to smash a target without leaving a wake. Only 50 were made between 1870 and 1889 by a Rhode Island company before the competition copied the design. There are two others of its kind known to exist, housed in naval museums in Washington and Rhode Island. Now dolphins working for the Navy have turned up a third.

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MORE ABOUT: bees, dolphins

How Marine Stowaways Hatch Alien Invasions

By Perrin Ireland | May 28, 2013 1:37 pm

In our increasingly globalized world, it’s not just commodities that get shipped around—ocean critters all too often tag along. Now scientists have developed a model to predict which ports and shipping routes are most at risk for invasions by non-native species.

Researchers from the University of Oldenberg in Germany, led by Bernd Blasius, used information from three million ship trips between 2007 and 2008 to study 1,400 ports and identify those most likely to be receptive to an invasion.

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CATEGORIZED UNDER: Living World, Science, Top Posts
MORE ABOUT: invasive species, ocean

An Icy Critter Cocktail Helped Baleen Whales Evolve

By Perrin Ireland | May 13, 2013 12:24 pm

One way to understand how the ecosystem of the Antarctic originated is to look at its very base: tiny organisms called dinoflagellates, the little creatures that attract bigger creatures, and thus in effect support all of life in the ocean. Dinoflagellates produce hard cysts that fossilize well, and researcher Sander Houben and his team recently published findings in Science indicating that, once Antarctic ice began to spread over what was formerly a lushly forested, warm sub-tropical continent, the makeup of the ocean’s dinoflagellate population dramatically changed.

The Antarctic ice sheet began spreading to inland Antarctica about 34 million years ago, during a climactic shift caused by a decrease in atmospheric carbon dioxide that was cooling the planet, known as the Eocone-Oglicene extinction event.  The Antarctic ice sheet is one of two polar ice caps on Earth, and covers 98% of the Antarctic continent, making it the largest single ice mass on Earth. Put another way, that’s 61% of all fresh water on Earth, held in the ice cap.

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MORE ABOUT: Antarctica, ocean, whales

Life Could Have Evolved in Frigid Underwater Ice Gardens

By Perrin Ireland | May 6, 2013 10:00 am

New evidence indicates that chemical gardens which form beneath the Antarctic ice could be the origin of coldwater life.

Brinicles, first captured forming on film by the BBC in 2011, are hollow tubes of ice that descend from Antarctic sea ice. They look a lot like icicles, but aren’t. As sea water freezes into ice, it excludes salt and other ions, which get trapped in brine-rich compartments in sea ice. Brine has a lower freezing temperature than water, so if the sea ice cracks, the liquid is released, and immediately freezes any seawater that it comes in contact with, creating a hollow tube of ice descending into the water.

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CATEGORIZED UNDER: Environment, Top Posts
MORE ABOUT: arctic

Menagerie of Animals Launched Into Space

By Perrin Ireland | April 28, 2013 12:41 pm

Last Friday, a crew of geckoes, forty-five mice, eight Mongolian gerbils, fish, snails, and plant seedlings were rocket launched on the Bion M1 into space, for the longest animal space experiment to date, a round trip lasting thirty days. The Russian spacecraft will relay information to scientists on the ground interested in studying the health effects of space on the animals.

Animals were the pioneers for manned space flight. Scientists wanted to make sure animals could survive before they sent any humans. Russia sent dogs, rabbits, and mice on short duration flights in the early 1960s.

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CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: Bion-M1, space-zoo

I Can See Clearly Now, the Brain is Gone

By Perrin Ireland | April 26, 2013 1:09 pm

It’s been a big month for developments in transparency.

First: the Antarctic icefish, whose native habitat is 3,200 feet deep in the waters off the coast of Antarctica. Earlier this month, Tokyo Sea Life Park debuted its display of the only captive icefish in the world, prompting a flurry of news pieces about the fishes’ mysterious clear blood. The aquarium boasts they now have a mating pair of icefish, which could enable studies on their unique cardiovascular system in a controlled environment.

 

 

What makes the icefish so remarkable is that it defies yet another one of those rules of biology that seem to always have exceptions. In this case, it’s the rule that all vertebrates were thought to have red blood. This is because of hemoglobin, an iron-containing oxygen transport protein in the red blood cells of vertebrates. It carries oxygen from respiration organs like lungs or gills to all the tissues of the body, where it releases the oxygen to help power the tissues of the organism. Hemoglobin also collects the carbon dioxide produced from the activity of tissues and carries it back to the respiratory organs to be exhaled, and expelled from the body as waste.

 

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CATEGORIZED UNDER: Living World, Top Posts

Saturn Gets Drenched by Its Eroding Rings

By Perrin Ireland | April 20, 2013 10:54 am

Ethereal, stately Saturn, it turns out, deals with a problem we Earthlings are quite familiar with this time of year: rain. The planet gets an Olympic-pool sized quantity of water dumped on her each day.

Studying satellite images taken at the Keck Observatory in Hawaii, James O’Donoghue, a postgraduate researcher at the University of Leicester, and his colleagues noticed several mysterious dark bands on the surface of Saturn. They found that the bands correlate directly to magnetic lines that link the planet with her densest, wateriest, and most brilliant, rings, and shared these cosmic findings in a letter to Nature last week. The drizzle coming from her rings effectively douses the glowing hydrogen molecules we see on Saturn’s surface.

Saturn is famous, among humans, for her very photographic rings. But their origins, and evolution, have remained a mystery. How exactly were the rings formed to begin with? Are the rings we see today remnants of a previously more massive ring system? These recent observations  indicate than an electromagnetic erosion force pulls charged water molecules from the rings and deposits them in Saturn’s upper atmosphere, called an ionosphere. Perhaps this process is playing a part in shaping the rings over time.

The rings, which look like marvelous elliptical beams of light as seen in satellite images, are actually bands of collisional, self-gravitating water-ice sludge rocks, some of which are submicrometer-sized, and others the size of mini-moonlets a few kilometers across. All these watery ice objects behave like a dense gas together, orbiting Saturn in a thin disk.Saturn behaves like a big magnet, with magnetic field lines that link her rings to her body. Remember that iron-filing experiment in school? It’s like that.  The ionosphere of Saturn’s rings is “seen” by the magnet that is Saturn, says  O’Donoghue, “and effectively bounces back and forth from ring-to-planet. Some of these bouncing water particles go too far and never come back.”

There’s not much danger of the moonlets in the rings going anywhere, but the small particles in the orbiting disks behave differently when they acquire a significant electrical charge. When the sun charges the water molecules, they become vulnerable to getting swept down towards the planet’s upper atmosphere along the magnetic field lines.

The researchers estimate that about 30-40% of Saturn’s upper atmosphere is flooded regularly, the equivalent of between 1 and 10 Olympic-sized swimming pools a day. It may be, then, that these magnetic field lines are responsible for shaping the spacing and composition of the rings.

Thanks to James O’Donoghue for kindly answering my questions and consulting on images.

A fun video about how Earth’s magnetic field interacts with the Sun’s to create aurorae:

CATEGORIZED UNDER: Space & Physics, Top Posts
MORE ABOUT: saturn

Peering Into Trilobite Eyes to See the Evolution of Vision

By Lisa Raffensperger | April 11, 2013 2:21 pm

They might not seem like the most expressive eyes you’ve ever seen—but the beady eyes of extinct trilobites have a lot to say. Recently, they’ve given us some new insights into the evolution of vision.

Trilobites are one of the first animals in the fossil record to develop complex eyes (as opposed to the light-sensitive spots that passed as early eyes). So understanding trilobite vision is also understanding the origins of eyes themselves. It has even been hypothesized that trilobite vision drove rapid changes in their prey’s body structure as prey evolved to escape sighted predators, thus fueling the Cambrian Explosion.

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CATEGORIZED UNDER: Living World, Top Posts
MORE ABOUT: eye, fossil, trilobite, vision

Rocket Engines Recovered From Their Watery Graves

By Perrin Ireland | April 4, 2013 3:04 pm

Jeff Bezos, founder of Amazon, is on a mission to retrieve the Saturn V rocket stages and engines from a watery “sculpture garden,” as he calls it, at the bottom of the sea off the coast of Florida. In a blog post on March 20th he announced that the endeavor to bring some of the F1 engines from Saturn up to the surface has been successful.

The size of small office buildings, the Saturn V moon rockets are the most powerful rockets ever to have flown. When tested, their engines shattered the windows of nearby houses. To date, the Saturn Vs are the only launch vehicles to have transported human beings beyond the low Earth orbit.

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CATEGORIZED UNDER: Archeology, Top Posts
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