June 11, 2013
Science is generally considered a rather serious business, full of big questions, dense calculations and incomprehensible jargon.
Then there is the Annals of Improbable Research, a venerable journal that has published data on the effects of peanut butter on the rotation of the Earth and how access to television can be an effective method of birth control. The publication’s stated goal is to publish “research that makes people laugh and then think.” Its articles—which are mostly satire, but with some occasional real research into offbeat issues—probably accomplish the former goal more often than the latter, but they do often contain a grain of scientific truth at their core. And, of course, the organization’s Luxuriant Flowing Hair Club for Scientists™ is an indispensable institution on the international scientific landscape.
For your reading pleasure, we bring you an (admittedly unscientific) list of the 5 most improbable research projects from the Annals:
How did Fiorella Gambale, a scientist at the (nonexistent) Institute for Feline Research in Milano, Italy, answer this age-old question? Simple: she dropped the cat Esther 100 times each from a variety of heights and charted the results. Improbably, the cat landed on its feet all 100 times when dropped from 2, 3, 4, 5 or 6 feet, but failed to do so even once when dropped from 1 foot.
Although these results were never vetted by other scientists—so there’s no way of knowing whether Gambale actually performed the tests—the finding that cats really do land on their feet when dropped from more than 12 inches from the ground actually does jibe with established scientific beliefs. The explanation is that they need a few seconds of free fall to trigger their righting reflex, which allows them to bend their back and twist their torso to orient their feet towards the ground.
“The field of culinary evolution faces one great dilemma,” wrote Joseph Staton, of Harvard’s Museum of Comparative Zoology. “Why do most cooked, exotic meats taste like cooked Gallus gallus, the domestic chicken?” Staton tasted a wide variety of meats (including kangaroo, rabbit, goose, pigeon, and iguana) in exploring the question, and ultimately determined that the quality of “chicken taste” is a conserved trait, something that came about once in the evolutionary history of invertebrates and was passed on to many species.
Sadly, Staton’s attempt to sample dinosaurs was thwarted: He apparently made several calls to Chicago’s Field museum to “borrow merely a single bone” from their T. rex but his request was “entangled in red tape.”
A team of geologists from Texas State and Arizona State Universities addressed this very serious question with the cutting-edge tools of their field: digital elevation analysis software, complex mathematical equations, and a standard-size flapjack from the local IHOP. They found that Kansas is, in fact, considerably flatter than an average pancake, which is actually more rugged than the Grand Canyon when viewed up close. They write that Kansas, on the other hand, “might be described, mathematically, as ‘damn flat.’”
Comparing these two fruits is not quite so difficult, it turns out, when you have access to a Nicolet 740 FTIR spectrometer, which can precisely measure the frequencies of light emitted from any substance. Scott Sandford, a NASA researcher, put this device to use on dried samples of a Granny Smith apply and Sunkist orange that had been pulverized and compressed into pellets. He found that the spectrums of light emissions from the fruits were remarkably similar, a rather stunning revelation given how frequently people employ the what he calls the “apples and oranges defense”: that we should avoid comparing two different things because of how different the fruits are.
“It would appear that the comparing apples and oranges defense should no longer be considered valid,” Sandford wrote. “It can be anticipated to have a dramatic effect on the strategies used in arguments and discussions in the future.”
Alice Shirrell Kaswell, a staff member at the Annals of Improbable Research, definitively answered this question once and for all in 2003: The chicken, it turns out, came approximately 11 hours before the egg. Kaswell came to this finding by separately mailing a dozen eggs and one (1) live chicken via the U.S. Postal Service from Cambridge, Massachusetts to New York City. Both items, sent out on a Monday, arrived on Wednesday, but the chicken was delivered at 10:31 a.m., while the eggs didn’t arrive until 9:37 p.m. Problem = solved.
June 6, 2013
Take a close look at nearly any male land bird—say, a rooster, hawk or even a bald eagle—and you’ll notice that they lack something present in most male animals that have sex via internal fertilization. Namely, a penis.
With a few exceptions (such as ostriches, ducks, and geese), male land fowl have no external sex organs. Instead of using a penis to fertilize a female’s eggs during mating, they eject sperm out of their cloaca—an orifice also used to excrete urine and feces—directly into the cloaca of a female (the maneuver is known by the touchingly romantic name “cloacal kiss”).
The evolutionary reason why these birds don’t have penises remains a mystery. But new research has finally shed light on the genetic factors that prevent male land birds from growing penises as they mature.
As described in an article published today in Current Biology, researchers from the University of Florida and elsewhere determined that most types of land fowl actually do have penises while in an early embryonic state. Then, as they develop, a gene called Bmp4 triggers a cascade of chemical signals that causes the cells in the developing penis to die off and wither away.
The team, led by Martin Cohn and graduate student Anna Herrera, compared the embryonic development of two types of land birds that lack penises (chickens and quail) with two species of waterfowl that have coiled penises that can be elongated (geese and ducks). Using an electron microscope, they found that in the early stages of development, male embryos from both of these groups had penis precursors.
But soon afterward, for the chickens and quail, the Bmp4 gene activates in the cells at the tips of the developing penises. This gene triggers the synthesis of a particular protein called Bmp4 (bone morphogenetic protein 4), which leads to the controlled death of the cells in this area. As the rest of the bird embryo develops, the penis shrinks away, ultimately producing the modest proto-phallus found on the birds as adults.
To confirm the role of the Bmp4 gene, the researchers artificially blocked the chemical signaling pathway through which it triggers cell death, and found that the chicken embryos went on to develop full-fledged penises. Additionally, the researchers performed the opposite experiment with duck embryos, artificially activating the Bmp4 signal in the cells at the tip of the developing penis, and found that doing so caused the penis to stop growing and whither away as it usually does in chickens.
Knowing the genetics behind these birds’ lack of penises doesn’t explain what evolutionary benefit it might confer, but the researchers do have some ideas. Male ducks, for instance, are notorious for having sex with females by force; by contrast, the fact that most land birds have no penis means that females have more control over their reproductive destiny. This could theoretically allow them to be more choosy over their mates, and select higher quality males overall.
Of course, all this might make you wonder: Is there really a point to studying the missing penises of birds? Well, as noted after the brouhaha that erupted a few months ago over federally-funded research into duck penises, research into seemingly esoteric aspects of the biological world—and, really, the natural world as a whole—can provide very real benefits to humanity in the long-term.
In this case, a better understanding of the genetics and chemical signals responsible for the development of the organ could have applications that stretch much farther than even the duck’s penis. Many of the particulars of embryonic development—including the Bmp4 gene and associated protein—are highly conserved, evolutionarily, meaning that they’re shared between many diverse species, including both birds and humans. So researching the embryonic development of even animals that are only distantly related to us, like birds, could one day help us better understand what goes on when human fetuses are in the womb and perhaps enable us to address congenital defects and other deformities.
And if that doesn’t do it for you, there’s also just the astounding weirdness of watching duck penises unfurl in slow motion. Brace yourself:
May 30, 2013
Think of an ecosystem as a Jenga pillar. Each piece–microbes, birds, trees, insects, animals, fungi–comes together to form the larger, intertwined structure. Maybe you can knock out a Jenga block or two, but tamper with those components enough and the system will collapse. As ecologists well know, small changes in the environment–cutting down a few patches of forest, causing a local species to go extinct–can create cascading and potentially disastrous effects on the broader environment.
Like a teetering Jenga tower, predicting which of those changes will most significantly reverberate in the complex natural world is nearly impossible. So we wait to see the consequences. Today, an international team of researchers just identified a pointed example of one such fatal tinkering. In Brazil’s damaged Atlantic forest, the absence of large birds has caused seeds to shrink and become weaker, in turn threatening the forest’s future.
The story began more than a century ago, they found. Local people began hacking away at the Atlantic forest, which once covered more than 400,000 square miles of Brazil’s coast. Agricultural and livestock fields, as well as growing urban centers, divided swaths of jungle, creating isolated patches of green. By the time people realized there was value in keeping the forest around, nearly 90 percent of it had been lost. Much of what remains today occurs in isolated, random pockets, though those patches still represent some of the world’s most biodiverse forests.
When a forest becomes divided, like the Atlantic forest did, wildlife often loses its ability to disperse from one patch of trees to another. Larger species may not be able to survive in some of the smaller, resource-scarce patches, and hunters can more easily track down animals if they’re confined to a smaller area. This turned out to be the case for some large birds that once made their home throughout the Atlantic forest, including toucans and toucanets–prized for their brilliant plumage, the birds are a favorite of hunters.
Significantly, these birds’ big beaks–which open up more than half an inch, on average–make them key players in distributing larger seeds throughout the jungle. Smaller birds can’t swallow or fit those big seeds into their beaks, meaning the toucans and toucanets carry nearly sole responsibility for regenerating the jungle with new seedlings of several plant species.
The authors of this new study, published in Science, compared the size of more than 9,000 seeds from 22 palm plant populations–a major tree type in the Atlantic forest, several species of which are threatened. Some of the seeds came from robust patches of forest with lots of large birds, while others came from smaller patches where those birds have long been missing. In those smaller patches, they found, seeds of palm plants were significantly smaller.
The researchers also used statistical models to independently evaluate 13 different environmental variables, including soil type and climate, to find out whether they could have driven the size difference seen in the seeds instead. None of the other factors could explain the difference, suggesting birds–the primary transport mechanism for large seeds–as the most likely culprit. Additional genetic analyses indicated that, in the smaller forest patches, seeds most likely began shrinking about 100 years ago, or right around the time that coffee and sugar cane plantations began to boom. Human activities a century ago, the authors conclude, likely drove a rapid evolutionary change in the forest palms’ seed size.
When the birds disappear, the larger seeds do not get distributed throughout the forest. Only the smaller ones wind up in new plots of earth, which in turn sprout into more trees that produce smaller seeds. Gradually, the forest becomes dominated by smaller seed-producing trees.
Shrinking seed size is no small detail for forest palms. The larger the seed, the more nutrients that are packed in to give the seedling the best possible chances of survival in the tough jungle ecosystem. Prior research has found that forest palms that began life as smaller seeds are smaller on average after a year of growth than those that came from larger seeds, meaning that the runty plants are more likely to lose out to competition with other species. Smaller seeds are also more prone to drying out. Given that climate models predict hotter temperatures and longer periods of drought for South America in the coming years, this could be a serious problem for smaller-seeded forest palms’ survival.
If palms start dying out throughout the Atlantic forest, researchers have no idea what will happen to the tens of thousands of species that take shelter in the ecological web the plants help to maintain–a web that includes more than 11,000 threatened plants and animals. For those smaller jungle patches, the authors speculate, the choices long-dead humans made may lead to complete collapse of some of the world’s most diverse sections of rainforest. Like a real-life game of Jenga, those birds could prove to be the key piece that causes the entire jungle system to fall down.
April 24, 2013
Pop quiz: Why are flamingos pink?
If you answered that it’s because of what they eat—namely shrimp—you’re right. But there’s more to the story than you might think.
naturally synthesize a pigment called melanin, which determines the color of their eyes, fur (or feathers) and skin. Pigments are chemical compounds that create color in animals by absorbing certain wavelengths of light while reflecting others. Many animals can’t create pigments other than melanin on their own. Plant life, on the other hand, can produce a variety of them, and if a large quantity is ingested, those pigments can sometimes mask the melanin produced by the animal. Thus, some animals are often colored by the flowers, roots, seeds and fruits they consume
Flamingos are born with gray plumage. They get their rosy hue pink by ingesting a type of organic pigment called a carotenoid. They obtain this through their main food source, brine shrimp, which feast on microscopic algae that
naturally produce carotenoids. Enzymes in the flamingos’ liver break down the compounds into pink and orange pigment molecules, which are then deposited into the birds’ feathers, legs and beaks. If flamingos didn’t feed on brine shrimp, their blushing plumage would eventually fade.
In captivity, the birds’ diets are supplemented with carotenoids such as beta-carotene and and canthaxanthin. Beta-carotene, responsible for the orange of carrots, pumpkins and sweet potatoes, is converted in the body to vitamin A. Canthaxanthin is responsible for the color of apples, peaches, strawberries and many flowers.
Shrimp can’t produce these compounds either, so they too depend on their diet to color their tiny bodies. Flamingos, though, are arguably the best-known examples of animals dyed by what they eat. What others species get pigment from their food? Here’s a quick list:
Northern cardinals and yellow goldfinches: When these birds consume berries from the dogwood tree, they metabolize carotenoids found inside the seeds of the fruit. The red, orange and yellow pigments contribute to the birds’ vibrant red and gold plumage, which would fade in intensity with each molt if cardinals were fed a carotenoid-free diet.
Salmon: Wild salmon consume small fish and crustaceans that feed on carotenoid-producing algae, accumulating enough of the chemical compounds to turn pink. Farmed salmon are fed color additives to achieve a deeper shades of red and pink.
Nudibranchs: These shell-less mollusks absorb the pigments of their food sources into their normally white bodies, reflecting the bright colors of sponges and cnidarians, which include jellyfish and corals.
Canaries: The birds’ normal diet doesn’t alter the color of its yellow feathers, but they can turn a deep orange if they regularly consume paprika, cayenne or red pepper. These spices each contain multiple carotenoids responsible for creating and red and yellow.
Ghost ants: There’s not much more than meets the eye with ghost ants: these tropical insects get their name from their transparent abdomens. Feed them water mixed with food coloring and watch their tiny, translucent lower halves fill up with brilliantly colored liquid.
Humans: Believe it or not, if a person eats large quantities of carrots, pumpkin or anything else with tons of carotenoids, his or her skin will turn yellow-orange. In fact, the help book Baby 411 includes this question and answer:
Q: My six-month-old started solids and now his skin is turning yellow. HELP!
A: You are what you eat! Babies are often first introduced to a series of yellow vegetables (carrots, squash, sweet potatoes). All these vegetables are rich in vitamin A (carotene). This vitamin has a pigment that can collect harmlessly on the skin, producing a condition called carotinemia.
How to tell that yellow-orange skin isn’t an indication of jaundice? The National Institutes of Health explain that “If the whites of your eyes are not yellow, you may not have jaundice.”
April 11, 2013
Visitors to Guam’s forests find them quiet–eerily so: No chirping of birds can be heard overhead. But slithering in the shadows on the ground are snakes, each some six feet long. Brown tree snakes made their debut on Guam, the southernmost island in the Mariana Archipelago, when islanders were rebuilding after World War II. Most likely, they were stowaways in lumber shipments heading north through the Pacific Ocean from New Guinea. They quickly began feasting on the birds and small lizards they discovered in Guam’s dense forests, and–free to slither through the mountainous terrain without predators of their own–they completed an invasion of the island at a pace of one mile per year. By the late 1940s, the forests had largely fallen silent, and now, all of Guam’s native bird species are history.
Last fall, scientists from Rice University and the University of Guam published one of the first studies of the island’s extinct forest birds, which include species such as the Mariana fruit dove, Guam flycatcher and Rufous fantail. They focused on how the absence of birds has caused a spike in the spider population, which is 40 times greater on Guam than nearby islands.
Now, the researchers are turning their attention to the issue of Guam’s thinning forests—a consequence, they also believe, of the bird deficit. This summer they’ll launch a four-year study of 16 tree species, looking at how the loss of birds, which scatter seeds, is affecting tree distribution.
The study has its roots in an a-ha moment that lead scientist Haldre Rogers recently had while conducting another seed-dispersal study in Guam’s forests. “I noticed that there seemed to be a lot of gaps [in the trees] and that the pioneer tree species–such as papaya and sumak–were difficult to find on Guam, compared to nearby islands,” she explained to Surprising Science. She discovered that there were in fact twice as many such gaps on Guam per unit area of forest.
Pioneer trees, which are the first to appear after a disruption to the ecosystem and thrive in the full sunlight of open spaces in the forest, have small seeds that are consumed by small birds. “Without birds to move their seeds to these sunny spots in the forest, these quick-growing trees may be less likely to germinate or grow to their full size,” Rogers hypothesized.
The problem with such thinning is that it could change the structure of Guam’s forests. “There’s a concern that [they] may become filled with open areas and start to look more like Swiss cheese than a closed canopy forest,” Rogers said. In other words, what were once cool, dark forests could transform into hot, open sunny ones.
There are other possible explanations for the tree-thinning: An undiscovered forest disease could be targeting pioneer species, or mammals like pigs and deer might have a strong taste for the trees. But according to Rogers, there isn’t strong evidence to support either of these scenarios. The upcoming study will attempt to determine the cause definitively.
To that end, the researchers will cut down individual trees in various spots within Guam’s forests, creating new gaps in the forest. They’ll also remove trees from locations on two nearby islands that are still brimming with birds. Then they’ll monitor how long it takes the spaces to fill in and take note of which seedlings thrive on Guam versus on the other islands. It may seem that to get their results they’re destroying what they’re trying to study, but in actuality they’re taking down a tiny percentage of the island’s trees–20 total.
Guam’s situation is similar to that of tropical regions worldwide. “Animals involved in seed-dispersal are in decline in a lot of tropical forests around the world right now,” the co-principal investigator of the study, Amy Dunham, said in a statement. “It’s very important to understand the implications of those declines.” So far scientists have looked into the role of endangered mammals like lemurs, giant tortoises (PDF) and African forest elephants (PDF) in seed dispersal, but the upcoming study will be one of the first to focus on endangered birds.
It’s also the rare study to examine what happens when seed dispersal completely ceases–Guam being the only place in the world to experience whole-island forest bird loss in modern times. “The situation on Guam–which is tragic–provides us with a unique opportunity to see what happens when all seed-dispersal services provided by animals are lost from an entire ecosystem,” Dunham said.
The snakes, meanwhile, continue to dominate the island of Guam. The U.S. Department of Agriculture traps approximately 6,000 brown tree snakes each year, and yet there are still nearly two million slithering around the island. The snakiest patches contain 14,000 of the reptiles per square mile–one of the highest snake concentrations in the world.
In February, the Department of Agriculture embarked on a new tactic for tackling the snake problem: dropping dead mice laced with acetaminophen, which is fatal to them, into the jungle. ”We are taking this to a new phase,” Daniel Vice of the Department of Agriculture’s branch that focuses on wildlife services in Hawaii, Guam and other U.S. held Pacific Islands, said in a recent interview. “There really is no other place in the world with a snake problem like Guam.”