Museum researcher uses DNA bar coding to improve tropical butterfly classification

November 1st, 2011

By Danielle Torrent

Calisto confusa

Calisto confusa is named for its tendency to be confused with other butterfly species. Florida Museum lepidopterist Andrei Sourakov used DNA bar coding in a recent study to distinguish C. debarriera as a separate species, rather than a subspecies of C. confusa. © Photo by Andrei Sourakov

When Charles Darwin journeyed to the Galapagos Islands in the 1830s, he collected some mysterious birds that later helped shape his theory of evolution by natural selection. Dubbed “Darwin’s finches,” they became famous as an example of adaptive radiation, in which animals evolve from a common ancestor to utilize different ecological niches.

Two centuries later, on the Caribbean island of Hispaniola, a Florida Museum of Natural History researcher was attracted to a group of insects he calls “Darwin’s butterflies,” because of their similarly high degree of diversity derived from a common ancestor. But it wasn’t until 20 years after beginning his research on the genus Calisto as a University of Florida Ph.D. student that Andrei Sourakov found the missing link for understanding how the group should be classified.

“DNA bar coding was the perfect tool to look at this genus because a lot of these species were separated based on only wing patterns, and it’s difficult to prove whether these differences correspond to species, or just represent variation,” said Sourakov, Florida Museum Lepidoptera collection coordinator. “DNA actually allows us to evaluate if and when the gene exchange occurred.”

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Museum researchers name new ancient crocodile relative from land of Titanoboa

October 1st, 2011

By Danielle Torrent

Did an ancient crocodile relative give the world’s largest snake a run for its money? In the post-dinosaur world of giants, Florida Museum of Natural History researchers discovered a new species related to crocodiles they say ate the same freshwater fish as Titanoboa.

croc and Titanoboa

This illustration shows how Acherontisuchus guajiraensis looked in its natural setting. Titanoboa, the world’s largest snake, is pictured in the background. © Florida Museum illustration by Danielle Byerley

Sixty-five million years ago, when a mass extinction wiped out dinosaurs, flying reptiles, large swimming reptiles and many other marine animals, few survivors were left to tell the story.

But University of Florida researchers recently unearthed the second member of a family that lived alongside the beasts, yet mysteriously survived the theorized asteroid strike that forever changed the atmosphere of the world.

“The same thing that snuffed out the dinosaurs killed off most of the crocodiles that were alive at the time,” said Florida Museum of Natural History graduate student Alex Hastings, lead author of a study describing the new species of dyrosaurid published Sept. 15, 2011, in Palaeontology. “The dyrosaurids are one of the few groups to survive the extinction and later become more successful.”

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Florida Museum researcher sheds light on ancient climate change

September 1st, 2011

By Danielle Torrent

Karen Walker

Florida Museum archaeologist Karen Walker displays a southern quahog clam shell and other specimens from Pine Island. Using isotopic information extracted from the items, researchers determined cooler, drier temperatures and lower sea levels affected the island’s inhabitants from A.D. 500 to 800. © Photo by Kristen Grace

The mysterious appearance of numerous ancient duck bones dating to the sixth century at the Pineland archaeological site on Pine Island in southwest Florida was the first clue to one Museum researcher’s new understanding of the state’s environmental history.

Karen Walker, assistant scientist of south Florida archaeology at the Florida Museum of Natural History, knew it was odd to find so many bones since the winter migratory range for ducks normally extends to the northern Gulf Coast, but not as far as south Florida. This suggested a climate cooler than today’s.

Other clues from the same period include a change in residents’ firewood from black mangrove to pine, suggesting a drier landscape, and a reduction in the number of fish bones, indicating people were eating less fish.

Using isotopic information from southern quahog clam shells and marine catfish otoliths (ear bones) collected at the site, Walker and co-authors Ting Wang and Donna Surge of the University of North Carolina at Chapel Hill confirmed cooler and drier weather characterized southwest Florida from about A.D. 500 to 850. This time span correlates with a wide-scale climate episode known as the Vandal Minimum, which is also associated with lower sea levels.

“When we started out, we thought, ‘Well, why wouldn’t you want it to be cooler in south Florida, it must have been nice,’ ” said Walker, who co-authored the study published online April 11, 2011, in The Holocene. “But in the end, I realized it’s all about fish – if you lose your water, you lose your fish.”

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Florida Museum scientists receive rare giant squid for research

July 1st, 2011

By Danielle Torrent

giant squid

Museum researcher Roger Portell injects preservative into a 25-foot-long giant squid recovered off the coast of Jensen Beach by recreational fishermen in June 2011. © Photo by Jeff Gage

 

One of the mysterious legends of the sea, the giant squid has haunted sailors for hundreds of years. From the adventures of Homer’s Odysseus to Melville’s Ishmael, the unknown of the deep invokes fear that the creatures may even threaten ships.

In 1830, Alfred, Lord Tennyson depicted the fabled sea monster “The Kraken,” as “far beneath the abysmal sea,” and “with giant arms.” In the final lines of the poem, he wrote, “Then once by man and angels to be seen, In roaring he shall rise and on the surface die.”

It was this image that caught the attention of three recreational fishermen about 12 miles offshore from Jensen Beach Sunday, June 26, 2011. They spotted a 25-foot-long giant squid dying near the surface at about 11 a.m. and decided to slide it into the back of their 23-foot-boat so the sighting would not be lost as legend.

“I thought we definitely need to bring it in, because no one’s going to believe us if we don’t,” said Robert Benz, who was fishing with friends Joey Asaro and Paul Peroulakis. “I didn’t want to leave it out there and just let the sharks eat it.”

The next day, Museum researchers collected the deep-water specimen from the Florida Fish and Wildlife Conservation Commission Tequesta Field Laboratory in Palm Beach County. The specimen is the only one of its kind in the collections of the Florida Museum of Natural History on the UF campus.

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State benthologists honor curator Fred Thompson with lifetime achievement award

June 1st, 2011

By Danielle Torrent

Fred Thompson

Florida Museum malacology curator Fred Thompson works at his desk in Dickinson Hall, where a Haitian snail shell lies under a microscope. Thompson has worked at the Museum for more than 40 years and was honored with a lifetime achievement award by the Florida Association of Benthologists in May 2011. © Photo by Jeff Gage

Following more than 40 years of fieldwork, Florida Museum of Natural History malacology curator Fred Thompson was recently recognized for his research on freshwater organisms.

The Florida Association of Benthologists presented Thompson with the Award for Excellence in Contributions to Florida Benthic Ecology in recognition of accomplishments throughout his career. The award can be presented no more than once a year and was last awarded in 2008, said Gary Warren, an executive committee member and one of the association’s founders.

“It’s been awhile since we thought we had somebody worthy of the award,” said Warren, an aquatic invertebrate ecologist with the Florida Fish and Wildlife Conservation Commission. “Every one [of the members] has been dependent on Dr. Thompson’s identification manuals – he is a resource for people that have specimens they can’t identify and he’s always been available.”

The association is comprised of about 250 scientists throughout Florida whose careers involve benthology, the study of all aquatic organisms on the bottom of water bodies, from protozoa, clams and snails to worms and crayfish. The association presented Thompson with the award during its annual taxonomic workshop in May.

Though small, these creatures serve an important role in helping balance the ecology of water systems throughout the world. Snails are among the most expansive of aquatic animals and comprise the largest group of primary consumers (herbivores) in aquatic ecosystems, feeding on decaying plant materials, algae, aquatic fungi and yeast. It was these organisms that piqued Thompson’s interest as a high school student in the 1950s.

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Florida Museum scientists search for grape fossils at long-forgotten site in Peru

May 1st, 2011

By Logan Gerber

Digging for fossils

Steve Manchester, right, and field assistant Francisco Navarro dig for fossils at a site about six miles south of Talara, Peru. © Photo by Fabiany Herrera

In the spring of 2010, Steve Manchester, Florida Museum of Natural History curator of paleobotany, and Fabiany Herrera, a University of Florida doctoral student studying biology, visited a site in Peru containing fossilized grape seeds in hopes of shedding new light on what the climate in South America was like millions of years ago.

The scientists traveled to Talara in northwestern Peru to determine if the fossils at the site are 20 million to 30 million years younger than previously thought.

Researchers who studied seeds from the site in the 1920s believed they are 50 million years old. Based on similarities with fossil plants found at the Panama Canal, Herrera and Manchester believe the seeds are closer to 20 million years old. Although Herrera did not find the same grape species at the Panama site, he found other plant fossils known to be about 20 million years old with similar characteristics to the seeds found in Peru. These include members of the plant families Annonaceae, Arecaceae and Humiriaceae.

“Either we can verify what people thought and published before us or we discover and present something new,” Manchester said. “If the seeds are younger than everyone thought, it would have some really interesting implications from a biogeographical perspective and for future research.”

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New study pinpoints U.S. as source of worldwide fire ant invasions

April 1st, 2011

By Danielle Torrent

The sweet smells of spring fill the air as more and more people head to parks and playgrounds to enjoy the weather. While the air grows warmer and the promise of summer quickly approaches, picnic-goers and adventure-seekers head outdoors, facing the risks that come with it – from sunburns and allergies to bee stings and ant bites.

Residents of the southeastern U.S. have learned keep a close eye out for soil mounds to avoid the painful stings of the red imported fire ant. Highly aggressive, the ants are often discovered by humans only after stepping on a mound.

Fire ants

The fire ant Solenopsis invicta has plagued the southern U.S. since its unintentional introduction to the area in the 1930s. The fire ants pictured above were photographed outside Dickinson Hall on the UF campus Feb. 16, 2011. © Photo by Jeff Gage

“Fire ants are very annoying pests, and they cause people to suffer,” said Marina Ascunce, a postdoctoral associate with the Florida Museum of Natural History on the University of Florida campus. “People who are allergic can die (from ant stings).”

A study published in Science Feb. 25, 2011, could prove helpful in controlling the prominent red imported fire ant, Solenopsis invicta. Ascunce co-authored the study with Chin-Cheng Yang of National Taiwan University and the results show the southeastern U.S. has been the source of recent red imported fire ant invasions around the world.

The ants have had a foothold in the U.S. for decades since their introduction through a port in Mobile, Ala. in the 1930s. They were contained in the southeastern U.S. for decades until about 10 years ago, when the global traders assisted its spread into faraway places, including Australia, California, China, New Zealand and Taiwan.

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