Photograph by A. Ellis and S. Johnson, from "Floral Mimicry Enhances Pollen Export: the Evolution of Pollination by Sexual Deceit Outside of the Orchidaceae," American Naturalist, November 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.

Cooties (a.k.a. lice) can tell us about human evolution (photo by Jesse Rhodes)

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.

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.

The writer says that hyberbolic crochet (her works, above) can be "kind of addictive." (Photo courtesy of Helen Fields)

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.

For more information on the Hyperbolic Crochet Coral Reef at NMNH, including how to contribute: http://www.mnh.si.edu/exhibits/hreef/index.html

Guest blogger, and knitter, Helen Fields has written about snakeheads and dinosaurs for the magazine and can be found at Hey Helen.

• 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

Next stop for humankind, Mars? (Image Credit: NASA/JPL/Cornell)

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.”

–Abby Callard

The Crew of the Apollo 8, Courtesy of NASA

One of the true pleasures of science reporting is listening to scientists describe algae, rocks or black holes with passion. They recollect the countless overnighters in the lab during graduate school. Some are brought to tears recalling when a problem they were investigating just made sense.

Unfortunately, by the time these interviews are translated into a news or magazine article, many of their personal stories are lost. Journalists often use 10 percent or less of the material they gather during research for a story, and so interesting and emotional details are lost forever in Word documents or mp3s.

Oral histories are the way to keep these stories alive and available to the public. They are valuable because they record individual memories at a particular place and time. (For a full discussion of their value, and a complete list of science-related projects, see “Oral History of American Science: A Forty Year Review” [PDF] by Ronald E. Doel.)

In the 20th century, dozens of archival oral science history projects were started in the United States. Most, like the Laser History Project and the Cornell Cold Fusion Archive, focused on a specific niche. Unfortuantely, very few audio files from these projects have been digitized, but many transcripts are available online.

Here are three stories captured by oral history:

1. Apollo 8 – NASA Johnson Space Center Oral History Project

Apollo 11, the first manned mission to land on the Moon in 1969, may be the Apollo everyone remembers, but Apollo 8, the first manned space voyage in 1968, was just as groundbreaking. “Apollo 8 was about leaving and Apollo 11 was about arriving,” says former astronaut Michael Collins, in the above audio documentary. “When you look back 100 years from now, which will be more important?”

2. Computer Etymology – Computer Oral History Collection

Long before the iMac, a computer was a person that made mathematical calculations. But By the 1930s, scientists were imagining and creating mechanical computers. According to the inventor the electronic digital computer [PDF], John Vincent Atanasoff (1903-1995), “from 1932 onward, we called those things computers—we just allowed the context to differentiate between whether the computer was a man or a machine. “

3. Twin Study – Oral History of Human Genetics Project

Victor McKusick (1921-2008) is considered the father of clinical medical genetics, the use of genetics to diagnose and treat disease. He cites a stay in Massachusetts General Hospital with a strep infection as the beginning of his path towards medicine: “I would have ended up a lawyer if it weren’t for the microaerophilic streptococcus,” McKusick said on tape. An environmental factor, he added, as law was the calling for his twin brother Vincent, who later became a Maine Supreme Court justice.

– by Joseph Caputo

Pacific coral, Acropora millepora, under fluorescent light. (Courtesy of Misha Matz, The University of Texas at Austin.)

The ocean is getting warmer, higher and more acidic due to climate change. How well will coral reefs respond to such stresses?

To find out, a team of researchers led by the University of Texas at Austin is looking to corals’ genes. Sequencing a genome can take years, but a new method developed by the UT researchers reduced that time frame to one month. They focused on the nearly 11,000 genes that the coral actually uses, instead of the unused genes and DNA bits that make up most of the organism’s genome.

The scientists tested their method on the Pacific coral, Acropora millepora, and hope to see an explosion in research about coral adaption and evolution as a result.

– by Joseph Caputo

An employee at the National Zoo’s commissary prepares meals for residents at the Great Ape House.

Six-o-clock in the morning is when the action begins at the National Zoo. Think you’re grumpy without breakfast? Just imagine how Mei Xiang and Tian Tian, two of the Zoo’s giant pandas, would feel without their bamboo.

Yesterday morning, I joined a zoo employee in a truck marked, “The Bamboo Never Stops,” as he delivered approximately 250 stalks of the treasured plant to the pandas, apes, elephants and several other species that enjoy the low protein, high fiber content of the leaves and stalks.

When we returned, it was off to the kitchen. With the radio softly playing in the background, we watched as nutritionists mixed bananas, lettuce, apples, carrots and corn with dozens of animal-specific biscuits. They weren’t the warm and toasty buttermilk biscuits you may enjoy for breakfast, but chicken-nugget sized combinations of oats and grains lightly flavored with citrus.

Every animal has a personalized diet, designed by a team of zoo nutritionists. The diets account for personal tastes, whether the animal runs around a lot or remains stationary, as well as age and health. For example, one gorilla received a biscuit and greens along with a beet, onion, cucumber, melon and banana.

If you ever host a dinner party for the following zoo animals, here’s what you need to know:

For penguins: These flightless birds have a taste for seafood. They’d be happy with a variety of fish, krill or squid. And no need for silverware! It’s recommended that penguins be hand-fed.

For fruit bats: Don’t let their name deceive you. These guys are picky eaters. Depending on the crowd, you may be forced to serve fruit, nectar, pollen, insects, blood, small mammals, birds, lizards, frogs or fish. It’s best to make this one a pot luck.

For Asian small-clawed otters: You may be better off going to a steak house if you have these furry guys over. Minced beef, fish, hard-boiled eggs, and locally available shellfish and crabs should be provided. Though they may not mind a bit of dog or cat food.

Wondering what your local lion or zebra is eating? You can find more nutrition advice at the American Zoo Association Web site.

– Joseph Caputo