By Danielle Torrent
As a University of Florida graduate student, one of Erin Thornton’s first assignments was to identify turkey bones from an ancient Mayan archaeological site in Guatemala.
Determined to please her adviser, Thornton thoroughly examined the features of the bones, which dated to the Late Preclassic period from 300 B.C. to A.D. 100. She decided they were remains of a non-local turkey native to central and northern Mexico, Meleagris gallopavo gallopavo, commonly known as the Mexican Turkey.
But unbeknownst to Thornton at the time, her conclusion defied previous archaeological evidence – the species did not belong in the Maya area during the Late Preclassic period. According to the archaeological record, the Maya did not use the non-local Mexican Turkey until about 1,000 years later.
“To be honest, I was so focused on getting the morphological identifications correct to impress my doctoral adviser that I wasn’t necessarily thinking about what species should or shouldn’t be there in the Late Preclassic,” said Thornton, a research associate at the Florida Museum of Natural History on the UF campus and Trent University Archaeological Research Centre in Canada.
Thornton then consulted the Museum’s resident bird expert, ornithology curator David Steadman, who confirmed the identifications. But they needed additional evidence. So Steadman, Thornton and her adviser, curator of environmental archaeology Kitty Emery, collaborated with DNA analysts to verify the bones belonged to the Mexican Turkey, representing the earliest evidence of the species in the Maya world.
By Danielle Torrent
In 1947, a small package containing an unknown plant specimen arrived at the Florida Museum of Natural History Herbarium. For 37 years, the thorny stem and leaves sat pressed between pages of a yellowed newspaper, filed in a cabinet among the vast library of Florida plants, until University of Florida botanist Walter Judd encountered the specimen in 1984. Knowing it was from the Lake Wales Ridge in central Florida, Judd and herbarium curator David Hall traveled to the area in search of wild populations, but returned to Gainesville empty-handed. Pronouncing it extinct, they published a paper naming the mysterious plant Ziziphus celata.
“Celata means hidden, because the plant was hiding from us,” Judd said. “We searched every little scrub patch that we found, but we didn’t see it – we were hoping that this would kind of be like the pebble that gets the avalanche rolling, and soon enough, there was an article written about the plant in the local newspaper.”
The media attention attracted amateur botanists and collectors to the field, and three years later, native populations of Ziziphus celata were re-discovered. But the excitement was short-lived, as researchers soon learned the species was self-incompatible, meaning two different plants are needed to produce seeds.
In 2007, the tide turned again when additional populations were found, and recent research on the plants revealed they have some genetic diversity, giving new hope to the 15-year effort to re-establish one of the state’s most rare and endangered plants.
By Danielle Torrent
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.”
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 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.
By Danielle Torrent
When lice attack, it’s hard to call it a blessing.
People have been tormented by the blood-sucking parasites for thousands of years, awaiting the latest technology to annihilate them. But some researchers are counting their lice and shipping them to genetics laboratories, where they are used to unlock clues about human history.
David Reed, associate curator of mammals at the Florida Museum of Natural History, studies lice in modern humans to better understand human evolution and migration patterns. His latest study used DNA sequencing to calculate when clothing lice first began to diverge genetically from human head lice.
“We wanted to find another method for pinpointing when humans might have first started wearing clothing,” Reed said. “Because they are so well adapted to clothing, we know that body lice or clothing lice almost certainly didn’t exist until clothing came about in humans.”
The results of the UF study show humans started wearing clothes about 170,000 years ago, a technology which allowed them to successfully migrate out of Africa.
Funded by the National Science Foundation, the study is available online and in the January 2011 print edition of Molecular Biology and Evolution.
Lice are studied because unlike most other parasites, they are stranded on lineages of hosts over long periods of evolutionary time. Host-parasite coevolution allows scientists to learn about evolutionary changes in the host based on evolutionary changes found in the parasite.
“We use these lice as a marker, if you will, as a marker of their host’s evolutionary history,” Reed said.
By Vilma Jarvinen
In a letter to his friend and colleague,19th century naturalist Charles Darwin referred to the sudden and rapid diversification of angiosperms, or flowering plants, as “an abominable mystery.”
Today, University of Florida researchers are part of a nationwide team preparing to open a door into a better understanding of plant evolution by sequencing the genome of the single living sister species to all other flowering plants. This plant, Amborella trichopoda, is a large shrub found only in high altitude regions on the South Pacific island of New Caledonia.
“Amborella, although not the most beautiful looking plant, has emerged as sort of a poster child for flowering plants because it is the sister group, or closest relative, of all of the other approximately 350,000 living species of angiosperms,” said Doug Soltis, UF distinguished professor of biology and project co-investigator. “It will allow us to better understand the genomes of other flowering plants such as crops – corn, rice, beans, cucumbers, tomatoes, potatoes, and so on.”
By Bill Kanapaux
Florida Museum of Natural History researchers are collecting marine invertebrates on the French Polynesian island of Moorea as part of a massive effort to inventory the DNA sequence of every living species there.
The genetic information collected by scientists from the Florida Museum is part of a whole-system approach that will be used to study ecological processes in depth across the entire island. Moorea’s coral reefs in particular are considered crucial indicators of how natural systems respond to climate change.
“Nobody has ever sequenced a single place to this level,” said Gustav Paulay, the project’s team leader for marine invertebrates and the Florida Museum’s curator of marine malacology. “And nobody has ever investigated coral reef biodiversity this thoroughly in one place.”
The three-year Moorea Biocode Project recently completed its second year of collecting marine invertebrates. Several Florida Museum researchers were in the field from October to December using scuba gear, snorkels and wading nets to collect specimens for the first-of-its-kind project.
The Florida Museum scientists are one of seven teams collecting specimens on everything from terrestrial vertebrates to algae. Marine invertebrates make up about 50 percent of the species on the island, which is about 37 miles in circumference and 11 miles from Tahiti.
While based at the UC Berkeley Richard B. Gump South Pacific Research Station on Moorea, the UF team collects specimens up to three times a day. The catch includes crabs, shrimp, plankton, mollusks and worms.