3.31.2006

Lion Manes Are Just for Show

A lion’s mane may look like a shaggy security blanket, but new research from the plains of the Serengeti shows the long locks offer no protection when two rival males fight for the chance to mate. The study suggests the male lion’s mane serves mostly as a lioness magnet, and played an important role in the way male fighting strategy evolved.

The purpose of the male lion’s mane has long perplexed biologists. Because female lions roam in groups of three or four, and allow only one male to reside with them, competition between males is fierce. Rival males often fight to the death—with their enormous teeth and claws—to gain coveted access to a pride. This led many biologists to assume that the function of the thick manes was to make it harder for attackers to reach the vulnerable throat area. But over the years this assumption has been questioned, because field biologists who actually saw lion fights in action noticed the mane area was rarely targeted.

Evolutionary biologist Peyton West and her colleagues from the University of Minnesota used life-size lion dummies to test if manes indeed offered protection. The researchers first lured some big cats to the testing area by playing tapes of hyenas feeding at a kill, then presented them with the fake rivals. “Of course we worried that the lions wouldn’t be fooled,” West says. But many of the real lions attacked the fakes with a vengeance. (Sometimes the fakes worked so well, in fact, that even after the real lions knocked them over, according to West, “they tended to stick around and maul them some more.”)

The real lions attacked the models not at the neck, but on the back and hindquarters, putting a serious snarl in the protective mane hypothesis. To see if the males were avoiding the neck because the mane was acting as shield, the researchers repeated the tests with “maneless” fakes. But even with these exposed-neck models, the real lions went first for the backside. “We were pretty surprised to find so little evidence for protection,” West says, because “it’s so intuitive that the mane would work that way.”

But it turns out those shaggy manes are used for attracting females. In previous research published in 2002, West had shown that males with longer and darker manes were older, better fed, and better fighters. And because females rely on males to protect their cubs, it makes sense that females would prefer males with large manes. “Just as songbirds can advertise their quality though visual cues, so, apparently, do lions,” says field biologist Jon Grinnell of Gustavus Adolphus College in Minnesota. Grinnell says West’s study is “new and interesting, because it forces us to look at lions differently.”

Even though manes don’t offer protection now, West says a protective role could have been the reason the trait evolved in the first place. In the early evolution of the trait, she says, males may have gone straight for the neck, making individuals with manes harder to attack and thus more favored by natural selection. As evolution continued and more and more males developed manes, attacking the neck area would no longer have been an effective fighting strategy—leaving our modern lions with manes.

“The lion is an intensively studied species and probably the best known wild cat on earth,” says field biologist Luke Hunter of Wildlife Conservation Society-International, “but this study shows that good science is still revealing new things about the species and turning over popular misconceptions.”

Journal reference: Animal Behaviour, March 2006 (vol 71, p 609)

3.17.2006

Beginning of Time

Once upon a beginning of time, there was a Big Bang. At the exact moment of the Bang, a “cosmic egg” was conceived. Over time, it would cool down, spread out, and grow into the Universe. It would never stop growing.

One-tenth of a second after the Bang, there was enough energy to create matter: neutrons, protons, and electrons, some stable, some unstable. The Universe had a temperature of 30 billion degrees Kelvin and a density 30 million times that of water.  

One and one-tenth of a second after the Bang, the Universe had a temperature of 10 billion degrees Kelvin and a density 380,000 times that of water.

Just under fourteen seconds after the Bang, it had cooled to 3 billion degrees Kelvin. This made the neutrons and protons and electrons move more slowly; slowly enough, in fact, to stick together if they happened to collide. So, at this point in the egg’s development, one proton and one neutron and one electron could collide and form the first atom, deuterium.

Three minutes and 2 seconds after the Bang, the temperature dropped to below one billion degrees Kelvin. It was then cool enough for two deuterium atoms to collide and form another kind of atom, helium.

Thirty-four minutes after the Bang, the Universe was 300 million degrees Kelvin. It was only 10 percent as dense as water. The deuterium and helium atoms were still bouncing around, usually too much to form stable entities for significant periods of time.

Seven hundred thousand years after the Bang, the Universe was the same temperature as today’s Sun—about 4,000 degrees Kelvin. This was finally cool enough for all of the atoms to be stable. For the next few billion years, they morphed into stars and galaxies.

Fifteen Billion years after the Bang, the Universe exists as it does now.              Now.
          Now.

3.12.2006

Maria Mania

“The chief difference between it and a spider’s work is one of size, supplemented by greater complexity, but both are joys of geometric beauty. For the lines are of individually uniform width, of exceeding tenuity, and of great length. These are the Martian canals.”-Percival Lowell, Mars and Its Canals


Today, Percival Lowell is remembered as the founder of Lowell Observatory in Flagstaff, Arizona, the place where, in 1930, astronomers first discovered Pluto. But Lowell Observatory was originally built to showcase a different planet: Mars. It all started in 1877, when an Italian astronomer drew a new map of Mars with dozens of black lines, called ‘canali,’ which came to be translated as canals. This, paired with the new Suez and Panama Canal projects, seeded a Mars canal mania in the American public, a frenzy whose flames were only fueled in the following decades by sensational newspaper headlines and popular books. Percival Lowell, the fabulously wealthy writer of the Boston Lowells, would in his middle age suddenly succumb to his lifelong curiosity in the bodies of the sky. He opened his observatory in 1894, primarily to study Mars, and in 1906, wrote what would become the most famous tome on the subject: Mars and Its Canals. In every chapter, Mars and Its Canals hits upon the reason the canals were titillating: they imply an artificial, complex infrastructure that must have been made by some kind of intelligent inhabitants. And though now we know Mars has no canals, many historians suggest the frenzy never stopped, and in fact continues to drive scientists in their unremitting search for extraterrestrial life today. Strangely enough then the canal myth, its easy public reception, and its lasting reverberations, all came about from but one word’s mistranslation.

In the late August of 1877, from the roof of Milan’s Brera Palace, a colorblind astronomer set the sights of a new Merz telescope on the surface of Mars. The astronomer, Giovanni Schiaparelli, had made his reputation on the study of meteors and comets, and wasn’t particularly interested in Mars. But his new telescope, an instrument made especially for yellow and red light, was ideal for viewing the Red Planet. Moreover, he knew the next month Mars would be coming into opposition. Mars opposition—when the Sun is on one side of the Earth, and Mars is on the other—shows us the planet at its brightest, and only happens once every two years. So Schiaparelli merely wanted to take advantage of a favorable viewing opportunity, as he later explained, “to verify for myself what the books of descriptive astronomy expounded about the surface of Mars, its spots and its atmosphere.” His September observations roughly matched the few contemporary sketches of Mars. But because Schiaparelli felt these existing drawings were rudimentary at best, he assumed the daunting task of making a new and improved map of Mars, and of naming all of the prominent features of its geography.  

Schiaparelli’s labeled map, comprised of bright spots of “terrae,” or land, and dark spots of “maria,” or sea, reflected his maritime view of the martian landscape--a “clear analogy” of Earth.  But though Schiaparelli realized the martian “land” may not have held dirt, nor the “seas” water, he defended his Earth-centric labels by writing, in 1878, “Do not brevity and clarity induce us to use such words as island, isthmus, strait, channel, peninsula, cape, etc.?...After all, we speak in a similar way of the maria of the moon, knowing very well that they don’t consist of liquid masses.”

Along with islands, isthmuses, and straits, Schiaparelli denoted dozens of canali on his map as dark streaky lines, and described them as “a complex embroidery of many tints.” In Italian, canali means “channel,” and Schiaparelli often used it interchangeably with fiume, or river. But a few years later, when the news of his map finally made its way through Western Europe and across the Atlantic, canali was translated to the general public as neither channel nor river.

French engineer Ferdinand de Lesseps had completed the formidable Suez Canal in 1869, and had begun work on the Panama Canal in 1880. So by the latter part of the nineteenth century, the Western world had canals on the brain. On April 24, 1882, betraying this certain civil engineering fever that had just begun to sweep the nation, the New York Times wrote of the “assiduous” Italian astronomer’s dark streaks that he “styled as ‘canals,’ for they bear the appearance of long sea-ways, dug through the martial continents, as if a mania of shortcuts seized the inhabitants of the planet, and everybody residing there had become an active M. de Lesseps.” And these kind of sensational accounts were still running rampant a decade later. In the summer of 1892, the director of Harvard astronomical observatory William Pickering, telescope in arm, climbed the Andes in Peru to get a good look at Mars. In a series of telegraphs he sent to the New York Herald, Pickering told a receptive public of his hasty new observations, which included forty martian lakes and detailed weather reports with the dates and locations of martian snowfalls. (The quick publishing and quicker reception of Pickering’s telegrams may serve as a lesson on the importance of peer-reviewed scientific journals.)

The craze wasn’t limited to the smudged columns of daily tabloids. Two years later, the English translation of Popular Astronomy, a book written by founder of the French Astronomy Society Camille Flammarion, was released, in which he states: “Henceforth the globe of Mars should no longer be presented to us as a block of stone revolving in the midst of the void…but we should see in it a living world, a new world which no Columbus will ever reach, but on which, doubtless, a human race now resides, works, thinks, and meditates as we do on the great and mysterious problems of nature.” As psychiatrist and noted Mars historian William Sheehan says, “the whole phenomenon resembled in many ways a case of mass suggestibility or hysteria,”—and all from just a few smeary, dark lines.

Schiaparelli’s lines, as it turns out, were not canals, or even natural water channels, but an artifact of his color-blindness. Those with red-green color-blindness—a genetic disorder harbored by about 10 percent of men of European descent—have trouble seeing all colors, but especially red and green. For Schiaparelli, this meant that he missed the slight color variations that both his fellow astronomers and more modern ones saw on the martian surface. By his own admission, Schiaparelli wrote: “My eye doesn’t distinguish well the gradations of red and green colors. The general appearance of the planet for me was almost that of a chiaroscuro made with Chinese ink upon a general bright background.” Schiaparelli saw the gradations as distinct contrasts, which he denoted as hard and fast lines. And in the decade following his first map, he received wide criticism in the scientific literature for these oversights (or perhaps, undersights). But the criticisms were too few, too late—the image of a canalled mars had already dug deep into the public’s imagination. And Percival Lowell’s.

In 1892, 37-year old Percival Lowell was on his way to Japan to research a series of articles he would write for the Atlantic Monthly about Japanese art and culture. But just before he left, he made a stop in Cambridge to tour Harvard’s observatory, and asked director Pickering for copies of Schiaparelli’s maps. These maps, and a small telescope, went with Lowell to Japan. Still there a year later, Lowell heard that Schiaparelli's deteriorating eyesight was forcing him into retirement and, as the oft-repeated story goes, immediately decided to continue the blind man’s legacy.

Historians may never know exactly when Lowell’s Mars interest was spurred, but by early 1894 he was interested enough to move to the Arizona Territory and open an observatory. A mile went of downtown Flagstaff, Lowell set up shop on a steep bluff he named Mars Hill. And the idea that Lowell saw himself as Schiaparelli’s successor is not so hard to fathom, especially considering the dedication of 1906’s Mars and Its Canals:

To
G.V. SCHIAPARELLI
THE COLUMBUS OF A NEW PLANETARY WORLD
THIS INVESTIGATION UPON IT
IS APPRECIATIVELY
INSCRIBED

Unlike Schiaparelli, Lowell’s eyes could see the subtle color variations on the martian surface. Though, as the title of his book suggests, this in no way deterred his belief in the existence of the canals, nor the existence of intelligent martian life. Lowell knew that Schiaparelli’s thin lines, in order to be seen with his telescope on earth, would have to be over thirty feet wide and thus much too big to be canals. So Lowell proposed that the dark lines were not the canals themselves, but rather bands of vegetation growing along their banks. And he further argued that lush vegetation grew thanks to a fairly mild climate, with little wind or rain storms: “That we can scan the surface as we do without practical interruption day in and day out proves the weather over it to be permanently fair. In fact a clear sky, except in winter, and in many places even then, is not only the rule, but the rule almost without exceptions.”

In addition to tree-lined canals and a mild climate, Lowell saw from his telescopes evidence of intelligent life. This evidence came mostly from logical inferences. He argued that the super-straight lines, many running for thousands of miles, were too ordered and too complex to be naturally-occurring geological features—they had to have been engineered. As he explained: “From the fact that the reticulated canal system is an elaborate entity embracing the whole planet, we have not only proof of the world-wide sagacity of its builders, but a very suggestive side-light to the fact that only a universal necessity such as water could well be its underlying cause.” The inhabitants of Mars, Lowell wrote, used the canals to direct flowing water as it melted from the planet’s polar ice caps, effectively fending off starvation on the otherwise arid planet. And by doing so, Lowell felt they surpassed even the best of our own technological feats.

Lowell’s book dedication to Schiaparelli is appropriate for another reason: he didn’t really advance the study of Mars beyond where his Italian mentor had left it (and, as we know now, Lowell’s ideas were flat out wrong.) His various theories about martian life activities, though prolific, were entirely speculative.  Astronomers of the day were not blind to this; on the contrary, just as Schiaparelli did decades before, Lowell received much criticism in scientific literature. Academic journals shunned his papers, so that his technical articles were only accepted by magazines for the layman like Popular Science and Popular Astronomy, or in the journals published in-house by his observatory. Some of his critics managed to air their slams in newspapers—one warned against Lowell’s "reckless theorizing" that was misleading "non-professional readers”—but nothing seemed to stick in the eye of his adoring public. He wrote three high-selling books, wrote frequently for the best-selling science magazines, and gave sold-out lectures on college campuses across the nation. His contribution to our study of Mars today lies not on the details of his theories or their rejection by scientific journals. Percival Lowell was a beloved American icon, and popularized Mars as only an icon can.

Not long after he opened Mars Hill in 1894, Lowell wrote a poem titled “Mars,” in which he reveals a desire that he would never fulfill: to leave Mars Hill and take the red safari “to that other island across the blue.” The poem continues:
Against hope hoping that mankind may
In time invent some possible way
To that longed for bourne that while I gaze
Through the heaven's heaving haze
Seems in its shimmer to nod me nay.

Mankind wouldn’t make the voyage for another six decades. The dawn of our modern space age came in 1960, when John F. Kennedy challenged America to put a man on the moon. In the same year, Russia would send the first probe to Mars. And in the next 46 years, after 37 more missions to Red Planet, we would find out that our blushing neighbor is much less charming than Lowell had imagined.

3.10.2006

NPR clip!

Oooo Sidebar!

http://www.npr.org/templates/story/story.php?storyId=5254713