October 1, 2010
Orchids have a reputation for deceiving pollinators, especially sexually, using floral ornamentation that beckons male mate-hunting insects to “come hither” and have a roll in the pollen. But a recent study (pdf) from the University of KwaZulu-Natal and Stellenbosch University finds that another fleur fatale has been lurking in the flowerbeds. Daisy family member Gorteria diffusa sports spots that bear a striking resemblance to flies—and those that most convincingly imitate a resting female bombyliid fly (those in the top row of the photo) elicit a strong mating response from love-hungry males. The flies that tried copulating with the spots were ultimately better exporters of that flower’s pollen than the female flies who landed on the blossom in search of food. The sexual deception ultimately allows for greater reproductive success for the daisy. The degree of sexual frustration for the flies has yet to be determined.
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Today’s post is by Smithsonian editorial assistant Jesse Rhodes.
September 13, 2010
Children all over America are returning to school this fall and I’m sure parents have done all they can to prep their youngsters—which hopefully involves any and all vaccines and boosters. But not even the most diligent efforts toward preventative health care can save your child from the bug that has been plaguing playgrounds for decades. I’m talking about cooties. You can try self-immunization—using your index finger to trace two circles punctuated by two dots on the back of your hand accompanied by prescription-strength poetry—but constant re-application is almost always necessary. And the folded paper cootie catchers do nothing but induce a placebo effect in affected persons.
But in all seriousness, it may surprise some of you to know that cooties are in fact quite real—but they’re not some strange, highly infectious disease afflicting persons of the opposite gender. “Cootie” is simply a slang term for lice, three types of which call the human anatomy home: head lice, which live exclusively on the scalp; body lice, which live on clothing and migrate onto the skin to feed; and pubic lice, which should be pretty self-explanatory. Offhand, the fact that we can harbor multiple varieties of the same parasite seems pretty lousy. However, research is showing that because these critters are so intimately adapted to our bodies, lice are quite useful in illuminating milestones in human evolution.
In a 2004 study, University of Florida mammalogist David Reed and his colleagues nitpicked over head and body louse DNA from all over the world. They found two genetically distinct types of head louse, one found worldwide and another exclusive to the Americas. Strangely enough, this would be possible if the two groups of louse had been living on the heads of two different species on different continents, the scientists say. Reed argued that both modern and archaic humans had their own types of lice. As modern humans—Homo sapiens—began to move out of Africa, they would have intermingled with Homo erectus—Homo sapiens’ evolutionary predecessors that were living in Asia and East Africa—picking up their archaic parasites along the way to the New World. These findings help to bolster the “Out of Africa” theories of human origins and early migrations. (Author Guy Gugliotta wrote a piece on human migrations for the July 2008 issue of Smithsonian.)
Another louse study done in 2008 by Reed and Didier Raoult on 1,000-year-old Peruvian mummies did a terrific job at debunking one of the long-standing myths of the Age of Exploration: the idea that Europeans introduced lice to the Americas. While Europeans were guilty of bringing new diseases, like smallpox, the mummies show that lice were alive and well in the New World well before gold- and glory-hunting explorers graced these shores. Furthermore, the DNA of the mummies’ lice is identical to that of lice originating in Africa, providing additional support for the diffusion wave model of human evolution and migration.
Lice also indicate when humans began wearing clothes. Early humans were covered with ape-like hair but started showing skin some 3.3 million years ago when they took to living in hot, savannah environments. (Bare skin promotes sweating and is a terrific way to keep cool, ergo much of the hair had to go, evolutionarily speaking.)
As humans started moving out of the savannah and into cooler climes, they had to start covering up. When they started wearing clothes, however, was always something of a gray area. But this past spring, a team of researchers led by Andrew Kitchen of Pennsylvania State University took a look at louse DNA and traced when head lice diverged from body lice, which have claws tailored to cling to fabric. That divergence was approximately 190,000 years ago. (A 2003 study led by geneticist Mark Stoneking gave a date of approximately 107,000 years ago.) The team deduced that humans began making and wearing clothing around this time.
And of course some of you out there may wonder where that intimate, third variety of louse came from. Oddly enough, the DNA record shows that its closest relative is the louse native to gorillas. Science has yet to provide an explanation as to how this happened. Bad case of “beer goggles” perhaps?
With that in mind, it’s almost certain that school-aged persons will soon be marching down to the nurse’s office to be tested for lice. And while we may have fun with them by way of games and songs, cooties are not to be taken lightly.
Jesse Rhodes is an editorial assistant for Smithsonian and blogs at Around the Mall.
July 29, 2010
This fall, a different kind of coral reef will be on display in the National Museum of Natural History’s Ocean Hall. It’s not made out of the calcium carbonate skeletons of living coral. It’s made out of wool. And acrylic, and cotton, and whatever other fibers local yarn artists get their hands on.
The exhibit is part of the Hyperbolic Crochet Coral Reef, a project started by two sisters in Los Angeles who run the Institute for Figuring, an organization that educates people about math and science. In about 2003, they started making models of hyperbolic space, a kind of space with surfaces that look undulating and ruffly, like a leaf of ornamental kale or a piece of kelp. The discovery of hyperbolic geometry in the early 19th century revolutionized how mathematicians thought about space; it launched the study of non-Euclidean geometry, the kind of math that underlies general relativity. Many cosmologists think the universe’s shape may be best described using hyperbolic geometry.
It’s a tricky concept to visualize – unless, it turns out, you use crochet. After a few years, the sisters started varying the patterns in their crocheted work, and the pieces of frilly mathematical space piled up until, one day, they noticed it looked like a coral reef. A project was born; with contributions from volunteer crafters, the reef has been displayed in museums in London, Dublin, New York, San Francisco and others. Now it’s headed for the Smithsonian.
So the other night, I went on an adventure in math, crochet and coral. About three dozen women turned up at the Yarn Spot, a store in Wheaton, Maryland. (The all-female crowd wasn’t unusual; the vast majority of the coral pieces have been made by women.) The Yarn Spot is one of 10 yarn stores in the D.C. area that are hosting workshops and crochet-along parties for the Smithsonian Community Reef.
Jennifer Lindsay, the program coordinator, talked about the history of the project, passed around sample pieces and explained how to crochet hyperbolic planes, pseudospheres and other shapes. Then she set us loose to crochet. People who needed to borrow a crochet hook or some yarn dug through one of Lindsay’s bins. Experienced crocheters crowded her to ask questions, while store owner Victoria Rothenberg took the beginners aside to teach them how to wield a crochet hook. A lot were knitters who are perfectly capable with two needles but flummoxed by the single hook of crochet (crocheting is, by the way, much easier).
The coral reef has moved away from the strict requirements of modeling hyperbolic space; crafters are encouraged to experiment with varying the shape, increasing stitches (which widens the fabric and makes it ruffle like a hyperbolic plane) as often as they want to, for example. This is just the way nature works, says Margaret Wertheim, one of the sisters behind the Institute for Figuring. “All these frilly and crenulated structures on the coral reef—sponges, nudibranchs—those are all basically imperfect hyperbolic variants.” Of course, the animal isn’t counting stitches, but it is varying its growth. “They have it in their DNA to grow like this, but it’s affected by their immediate environmental conditions.”
And you don’t have to stick to hyperbolic shapes; they will take crochet models of anything that sits on a coral reef, like clams and anemones. Heck, you don’t even have to stick to crochet. Knitting is welcome, too, as long as the product looks reef-like. Knitting is welcome, too, as long as knitters make hyperbolic shapes or combine knitting (or other fiber techniques like felting, tatting, embroidery, etc.) with crochet. Anyone can mail in pieces by August 30; the deadline for dropping pieces off at a local yarn store or at the museum hasn’t been set yet. The reef will be on display in the Ocean Hall from October 16, 2010 to April 24, 2011.
October 22, 2009
- According to New Scientist, physicists Tie Jun Cui and Qiang Cheng of the Southeast University in China have succeeded in creating the first black hole, built to absorb and trap solar energy. Based on a theory from Professors Evgenii Narimanov and Alexander Kildishev of Purdue University, the Chinese scientists used strips of “meta-materials” (previously used to create Potter-esque “invisibility cloaks”) to recreate the structure of a black hole. “When the incident electromagnetic wave hits the device, the wave will be trapped and guided in the shell region towards the core of the black hole, and will then be absorbed by the core,” says Cui. “The wave will not come out from the black hole.” According to Narimanov, should the creation work, it would allow for the collection of solar energy in areas with little exposure to light.
- Ever wonder what it’s like inside a black hole? Scientists at UC-Boulder created this animation to theorize what the experience would look like:
- In air and space news, one lucky robot is predicted to sail on Titan, one of Saturn’s moons. The idea to cruise in space was inspired by the discovery that Titan resembles Earth in many habits, particularly weather-wise. Titan experiences rain, wind, and has many lakes, however, liquid methane and ethane take the place of water. Ellen Stofan, a geologist with Proxemy Research in Maryland, explains that the lake-lander will fulfill one of the three-probe plan to explore this interesting moon. A “balloon-mounted vehicle and an orbiter” will complete the mission, enabling NASA to fully view and discover every region of Titan.
- From the BBC comes news of a “veggie spider” or Bagheera kiplingi, the only arachnid to feast only on plants. Avoiding ants and waiting patiently to snag a piece of its’ favored acacia plants – known as Beltian bodies, the spider really has to work for its’ vegetarian meals. Found in Central American and Mexico, this spider is perhaps the only one not feared by the people.
- Due to excessive animal poaching (104 per day!), African elephants will be extinct in little over 15 years, according to the International Fund for Animal Welfare. Despite the international ban on ivory sales, the illicit trade continues.
— Compiled by Audrey Reinhardt
July 20, 2009
Today, on the 40th anniversary of the Apollo 11 moon landing, the focus is not on the past, but on the future. The seven astronauts in attendance at this morning’s NASA news conference were not content simply to relish in the accomplishments of the past.
Astronauts Walter Cunningham (Apollo 7), James Lovell (Apollo 8 and 13), David Scott (Apollo 15), Buzz Aldrin (Apollo 11), Charles Duke (Apollo 16), Thomas Stafford (Apollo 10 and the Apollo-Soyuz Test Project) and Eugene Cernan (Apollo 10 and 17) gathered at NASA headquarters to discuss the achievements of the past and the promise of the future.
Many of the astronauts, including Aldrin and Cernan, think missions to Mars, instead of further exploration of the moon, are the future of space exploration. Cernan said he had thought that the space program would have been on its way to Mars by the turn of the century. Even though the program is behind this schedule, he says, Mars is the direction it needs to go. “The ultimate goal is truly the goal of Mars,” he says.
Aldrin, who also spoke about the necessity of Mars exploration last night at the annual John Glenn lecture at the National Air and Space Museum, echoed Cernan’s thoughts. “To me, exploration is going to some place you haven’t been before,” he says. But Aldrin also took the idea one step further.
He doesn’t want to just send astronauts to Mars and bring them back. He wants them to stay. After all, he says, the pilgrims didn’t go to Plymouth Rock to hang out for a while and then find their way back home. Neither should the Mars explorers.
Cunningham agrees but knows that money and politics, not technology, set the limits for space exploration. “We have to find a reason to go to Mars that can sustain the funding,” he says. Until then, the goal is unreachable.
The future of the space program might be uncertain, but the minds of these astronauts are made up: the moon landing 40 years ago isn’t an end, but rather an open door. To go through that door, Americans’ sense of adventure needs to be re-inspired, Cunningham thinks. We have transformed into a risk-averse nation, and that needs to change, he says. “There are some things worth risking your life for.”