Smithsonian.com

Scientists have excavated hundreds of 20-million-year-old fossils at the Panama Canal expansion sites. (Courtesy of STRI.)

There was a time when North and South America did not share a land border. Instead, a large river separated the two land masses. The animals and plants on the continents kept to themselves mostly, with the exception of the birds that refused to call any one place home.

Then, 15 million years ago, the North and South collided, volcanoes erupted and the Atlantic was separated from the Pacific. About 12-million years later, a land bridge formed between the two continents, and the animals and plants began to travel freely.

This land bridge formation occurred near the site of today’s Panama Canal, which makes the area an attractive site for paleontologists who want to learn the continental origins of individual species. Thousands of fossils, ripe for analysis, lie in the canal walls. But the scientists who want them must act fast. The Panama Canal widening project, due to be completed in 2011, has already removed 10-million cubic meters of earth, with more to come.

Teeth belonging to the three-toed browsing horse were unearthed in a Panama Canal widening site. Proof that the horse's range expanded from South Dakota to Panama 15-to-18 million years ago. (Courtesy of STRI)

Smithsonian researchers are now trying to stay one step ahead of the bulldozers. Working in collaboration with the University of Florida and the Panama Canal Authority, the scientists move in, following dynamite blasts, to map and collect fossils. As of last July, 500 fossils, from rodents, horses, crocodiles and turtles, some dating back 20-million years, have been uncovered.

“We expect the fossils that we have been salvaging to resolve some major scientific mysteries,” says Carlos Jaramillo, a Smithsonian Tropical Research Institute scientist. “What geological forces combined to create the Panama land bridge? Was the flora and fauna in Panama before the land bridge closed similar to that in North America, or did it include other elements?”

At least one answer to Jaramillo’s second question has already been found. Aldo Rincon, a paleontology intern, unearthed a set of fossilized chops belonging to the three-toed browsing horse, known to have grazed in Florida, Nebraska and South Dakota between 15-to-18-million years ago.

According to Beth King, the Institute’s science interpreter, (who was recently featured in a Scientific American podcast), the presence of this horse in Panama significantly extends the southern tip of its range from previous finds, supporting the hypothesis that the habitat was probably a mosaic of relatively dense forest and open woodlands.

There are many more fossils to be found at the Panama Canal widening site, and King expects there to be many papers published within the next five years regarding their significance.

Like pots? Participate in the "Ceramics in Mainland Southeast Asia" Webinar. Tonight at 8:00 p.m. (Courtesy of Freer and Sackler Galleries.)

For all of our readers who are experts or interested in Southeast Asian ceramics, bookmark the new online catalog published by the Smithsonian’s Freer and Sackler Galleries. It’s your one shot stop for in-depth information about Longquan ware covered jars from Zhejiang province, China, or Alms bowls from Burma.

Celebrate the creation of this new resource by participating in the webinar, “Ceramics of Mainland Southeast Asia,” to take place Tuesday, June 23, 2009, at 8:00 p.m., EDT, in collaboration with the John Hopkins University Museum Studies program. Join Louise Cort, curator of ceramics at the Galleries, along with a panel of experts, for a discussion of how the development of ceramics and the history of Southeast Asia are intertwined, and the clays and used in Southeast Asian ceramics.

Scott Solomon is a postdoctoral research fellow in the Smithsonian's Ant Lab. He blogs about his field experiences at "The Ant Hunter." (Courtesy of the scientist.)

When troops of “crazy rasberry ants” invaded Texas last year, surprised homeowners found the bugs wedged inside personal computers and shorting out  electrical devices. Even NASA grew concerned when the ants marched into the  Johnson Space Center. As the species’ seeming attraction to electronics became a news maker, Scott Solomon explained over at Slate:

“Invasive species like the crazy rasberry ant are adapted to environments that are constantly changing, so they are always searching for new homes. Electrical switch boxes, gas meters, or your PC make ideal homes because they are dry and have small, easily defendable entrances,” Solomon wrote.

Solomon, a postdoctoral research fellow at the Smithsonian’s Ant Lab, enjoys sharing his passion for science with the public. He wrote about the effort to create a virtual Lucy fossil for Wired.com and scribed science feature articles for his student newspaper at the University of Texas. But his most personal project is his blog, “The Ant Hunter,” where he shows, through pictures and words, both the unglamorous and the exotic world of entomological research.

In the blog, Solomon writes about crawling through a Brazilian desert at night, dodging scorpions and spiky shrubs, as he searches for ant colonies. The fieldwork he does is far from a leisurely vacation. At some points, dinner has consisted of instant coffee and crackers, highlighted by a trip to a nearby diner for grilled goat. Sleeping can be a hazard as well, especially if army ants are seizing your bed. And Solomon always seems to travel during the wet season. “Sometimes it’s miserable,” he says, “but I love it and it’s a lot of fun.” According to his 10-year-old cousin, Solomon is like the Crocodile Hunter for ants.

The Ant Hunter is also an amateur photographer of his work, as evident by his Flickr page. (Courtesy of S. Solomon.)

The blog began as a way for the ant hunter to keep in touch with family and friends abroad, and to keep writing skills sharp. But now that Solomon’s fieldwork has wound down, he plans on writing behind-the-scenes accounts of Smithsonian ant research for the general public.

But what exactly is there to research about ants? Solomon is interested in the origin of leafcutter ants. These are species that gather fresh leaves, and use fungi to break it down for nutrients. “It’s like an external digestive system,” he says. A huge number of new leafcutter ant species appeared in evolutionary history 10 million years ago and Solomon wants to know why.

He uses his trips to the wilderness of Brazil and other spots in South America to learn about the leafcutter’s closest relatives, Trachymyrmex, a relatively unknown genera of ants that also farm fungi. Solomon, who has an interest in evolutionary biology and genetics, hopes to use the information to determine the key molecular and ecological differences between leafcutters and Trachymyrmex. To learn how the research unfolds, be sure to follow The Ant Hunter on his blog.

With a title like that, perhaps the Smithsonian Channel will give Solomon his own series.

Ants star in the new Natural History Museum exhibition “Farmers, Warriors, Builders: The Hidden Life of Ants,” on view through October 10, 2009.

On August, 20, 2007, Smithsonian.com introduced Around the Mall—a blog covering the scenes and sightings from the Smithsonian museums and beyond. After nearly two years of reporting, we’ve reached our 400th post. To celebrate, here’s a look back at some of our favorite posts:

1.Nikki the Bear Lost 110 Pounds on the National Zoo Diet

When Nikki the spectacled bear came to the National Zoo, he looked more like Winnie the Pooh. At 500 pounds, Nikki was so obese that animal handlers had trouble locating his tail underneath layers of fat. Luckily, the National Zoo came up with a step-by-step diet plan to help Nikki shed the pounds within a year.

2. Carol Burnett-We Just Can’t Resist Her!

Movie parodies were always a mainstay of the Carol Burnett Show—and her 1976 Gone With the Wind takeoff is unforgettable. The curtain rod dress from the sketch now graces the hallowed halls of the Smithsonian as a part of the American History Museum’s Kennedy Center Honors collection. No word, yet, on if and when, it will go on public display, but we’ll be sure to keep you posted. Because, frankly, we give a damn.

3. Last Minute Halloween Costume Ideas

Last Halloween, we knew our readers were scrambling to get a costume together. We thought the portraits at the National Portrait Gallery might provide inspiration. Disney’s version of Pocahontas depicts her wearing a tasseled, leather dress. But that costume was already done by thousands of young girls. Pocahontas was converted to Christianity, baptized as Rebecca and married the English settler John Rolfe. So try pulling off Rebecca Rolfe. It might take some explaining. But don’t most last-minute costumes?

4. They Call Him the “Starfish Guy”

Christopher Mah is one of a growing number of scientists who are blogging. As part of a National Science Foundation requirement to make his research easily accessible, Mah started “The Echinoblog.” Now a year old, he has blogged on topics ranging from “Giant Green Brittle Stars of Death! When they Attack!” to “What are the World’s Largest Starfish?”

5. The Ruby Slippers Return to the Museum of American History

For 70 years, The Wizard of Oz has given faithful service to its evergreen fashion philosophy: there is nothing more important than owning the right pair of shoes. After a two-year vacation at the Air and Space Museum, Jesse Rhodes was among the first to see the shoes find their way home last fall to the renovated Museum of American History. There they are, and there they’ll stay.

6. That’s Some Bad Hat, Chuck. (As in Mangione)

Jeff Campagna was on hand with a tape recorder when a very dapper Chuck Mangione, dressed in all black, signed away a cache of his musical memorabilia to the Smithsonian’s National Museum of American History. Included in the donation were scores to his most important works, albums, photographs and his signature brown felt hat.

7. Secret Message Found in Lincoln’s Watch

It was high drama at the American History Museum back in March. Beth Py-Lieberman was on the edge of her seat. Word was out that a pocket watch that once belonged to Abraham Lincoln might have a secret message engraved inside of it. And sure enough, the inscription was there, “Jonathan Dillon April 13-1861 Fort Sumpter [sic] was attacked by the rebels on the above date  thank God we have a government.”

8. Science Education Grant Brings Sesame Street Planetarium Show

Joseph Caputo joined Big Bird and Elmo for a bit of stargazing at the National Air and Space Museum’s premier of Sesame Street’s “One World, One Sky” planetarium show. Listen to Caputo interview Elmo, who came to the premier dressed as an “elmonaut,” much to the delight of the preschoolers in the audience, what he learned from being part of the show.

9. National Postal Museum: Greening the Mail

Could we recycle more mail? The United States Postal Service has a green Web site that says that all mail is recyclable. Yet Michael Critelli, executive chairman of the mailing company Pitney Bowes, says that only 35.8 percent of it actually ends up in the recycle bin, as opposed to 77 percent of newspapers.

10. Rachel Carson: A Life That Inspires a Sense of Wonder

Actress Kaiulani Lee spent over three years studying Rachel Carson’s life and work before  composing and starring in her one-woman show, A Sense of Wonder. Pulling off a one-person anything requires an intensely magnetic personality—and Lee brings this to the table in spades. And, with about 80 percent of the show’s dialogue being culled from Carson’s writing, it’s an excellent introduction to the environmentalist’s life and legacy.

Shellfish, like oysters, are especially vulnerable to climate changed-induced ocean acidification. (Free image courtesy of Wikimedia Commons user Chris 73.)

In a paper published last month in PLoS One, a team led by ecologist Whitman Miller, showed that the shells of Eastern oysters, Crassostrea virginica, the jewels of the Chesapeake Bay, will be slightly smaller (16 percent decrease in shell area) and weaker (42 percent reduction in calcium content) in the waters of 2100. The other species tested, the Suminoe oysters from Asia, showed no change in an acidic ocean.

“We are bound to our bodies like an oyster is to its shell,” said Plato, the ancient Greek philosopher.

But that was over 2,000 years ago, long before rising levels of carbon dioxide began to trap heat in our atmosphere and seep into our oceans. As CO2 dissolves into seawater, it is broken down into carbonic acid and hydrogen ions. Hydrogen determines whether a liquid is acidic or basic. The more hydrogen ions that leach into the ocean, the more acidic it becomes.

As more of the green house gas, carbon dioxide, is released, the world’s oceans are slowly becoming more acidic, and shellfish, like oysters are especially vulnerable to this kind of change. An acidic ocean hinders the ability of some species of oyster young to build their shells, scientists with the Smithsonian’s Environmental Research Center found.

According to the scientists, the results suggest that acidification may be tied to a species’ unique evolutionary history, implying that predictions may be more complex than previously thought. “In the Chesapeake Bay, oysters are barely holding on, where disease and overfishing have nearly wiped them out,” Miller says. “Whether acidification will push Eastern oysters, and the many species that depend on them, beyond a critical tipping point remains to be seen.”