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
In ancient Mesoamerica, as the Aztec calendar predicted the end of the world with a total solar eclipse followed by a cataclysmic earthquake, neighboring cultures also looked to the heavens for signs of their future.
Their painted books depicted solar eclipses, comets and other celestial patterns, for the skies brought good fortune or bad, a successful crop season or dreaded famine.
Predictions and records of climate cycles appear in the Codex Borgia, the finest of the five Borgia group manuscripts to survive the Spanish conquest of the Aztec in 1521. Many scholars over the last few centuries have offered interpretations of events documented in the Codex Borgia, a 76-page screen-fold book made of deerskin, but they had not taken into account its origin in Tlaxcala and notation of real events.
New research using tree-ring data to match climate events described in the codex shows dates that may be deciphered using the Aztec calendar.
“Mesoamerica is a single cultural area and the calendar works similarly — many of the deities are the same, but unless we establish who made this codex definitively, we can’t talk about anything,” said Florida Museum of Natural History Curator of Latin American Art and Architecture Susan Milbrath. “Initially, Aztec sources were used to interpret it, then the Mixtec scholars around the 1960s started to claim it. Now, with the work of Tony Aveni and this study, we can definitively say it was Tlaxcaltec, but it’s taken about 40 years for it to get pulled back into the Aztec dialogue.”
By Danielle Torrent
The field of restoration ecology, in which native flora and fauna are re-established to create more sustainable environments, is taking off in the 21st century as researchers become more aware of the potentially negative impacts of invasive, non-native species. Humans are among the “non-natives” in many areas, having taken over as apex predators in many situations. In the Bahamas, the arrival of humans about 1,000 years ago led to a considerable disruption of the natural food chain.
With a three-year $164,000 National Science Foundation grant awarded in September 2011, Florida Museum of Natural History ornithologist David Steadman is digging into 6,000 years of history, with hopes that a better understanding of how island organisms respond to human influence may aide efforts to restore a more functional ecosystem. By collecting fossils from the Bahamas over the last 6,000 years, well before humans reached the area, he will also analyze how plant and animal communities responded to long-term natural environmental fluctuations.
“People arrived in the Bahamas and soon they wiped out the tortoises, they wiped out the crocodiles, and became a new apex predator capable of eating just about anything, marine or terrestrial,” said Steadman, Florida Museum natural history department chair. “People are also warm-blooded, or homeotherms, so we need more energy per pound of body weight to keep going. This requirement rearranges energy flows. All that gets complicated even further by people wiping out certain species, whether they’re prey species or other predators, and introducing non-native plants and animals.”
By Danielle Torrent
For morning drivers on the roadways of the northwestern U.S., an innocuous purple or yellow flower similar to a daisy should be a familiar sight. Widespread and often considered a weed, goatsbeard is also known as “John-go-to-bed-at-noon” because its flower only blooms for a few hours in the morning.
The European parent species of this plant never produced fertile hybrid offspring. But once the parents arrived in North America about 80 years ago, they not only formed hybrids, but those hybrids then experienced genome (chromosome) doubling. The parents yielded two new species (Tragopogon mirus and Tragopogon miscellus) native only to North America. Plants of these new species have since multiplied throughout the Pacific Northwest, with estimates of more than 10,000 near Spokane, Wash.
To better understand this phenomenon of genome doubling, which is common in plants, including many crops, Florida Museum of Natural History researchers re-created T. miscellus in UF greenhouses and analyzed its genes and chromosomes to find patterns that may have far-reaching evolutionary consequences.
“We caught evolution in the act,” said Doug Soltis, a distinguished professor in UF’s biology department. “New and diverse patterns of gene expression are seen and these may allow the new species to rapidly adapt in new environments.”
Pam and Doug Soltis have been studying T. miscellus for more than 20 years, and a series of publications have given scientists a clearer view into what happens when a hybrid species experiences a genome duplication event, or polyploidy, following hybridization.
By Danielle Torrent
Exactly 150 years ago, Henry Walter Bates described mimicry based on his observations of adult butterflies in the Amazon, thus contributing key evidence supporting Darwin’s then novel theory of natural selection.
Recently, while doing fieldwork in the lowlands of eastern Ecuador, Florida Museum of Natural History assistant curator of Lepidoptera Keith Willmott noticed another prime example of mimicry. Instead of looking up at the flyers, he found bright coloration in an earlier growth stage of butterflies — similar bright coloration in caterpillars was repeated in several unrelated species of ithomiine butterflies and again in a sawfly larva. Clad in blue and yellow with black tips, different species of the crawlers were not disguised as bird droppings or natural objects like many other caterpillars, and they were saying something different to their enemies: “Look out, we’re poisonous!”
Meanwhile, on the Caribbean island of Hispaniola, fellow Florida Museum lepidopterist Andrei Sourakov was documenting another curious example of different caterpillar species with similar, conspicuous color patterns. A banded black, white and yellow pattern appeared in several species of danaine caterpillars, which include the monarch butterfly and its relatives.
Together, the researchers, who work in the Florida Museum’s McGuire Center for Lepidoptera and Biodiversity, documented some of the most extensive examples of mimicry in caterpillars, in which different species mimic others as a defense against predators.
“Previous papers discussing mimicry mostly discuss a single, isolated case, typically involving a pair of species, but this is not just one pair, there are several species involved,” said Andre Victor Lucci Freitas, a professor in the Instituto de Biologia at Universidade Estadual de Campinas, who is familiar with the study. “There are lots of papers discussing mimicry in adult insects, but there are very few exploring mimicry of immature stages, like the caterpillar.”
By Danielle Torrent
During the 1800s, the world was going through transformations steered by war, invention, scientific innovation and the discovery of new land. The time period saw the collapse of some empires and the rise of others, from the British and Japanese to the booming United States of America. The Industrial Revolution brought about the invention of railroads, and cargo ships made an unprecedented number of journeys to the New World. But unbeknownst to conquerors, amphibians and reptiles were along for the ride, and their presence is having a seemingly irreversible impact today.
In Florida, it started with the first documented introduction of the Greenhouse Frog in 1863, a native of the West Indies. This species has become widespread and occurs in areas where many native frogs are now seldom seen. Circa 1887, cargo ships brought the brown anole from Cuba to the state, and the small, brown lizard is now one of Florida’s most easily recognized wildlife species. The state’s largest established invader, the Burmese Python, made its way from the rainforests of Southeast Asia to become household pets for Floridians, and recent studies show the devastating effects these up to 20-foot-long creatures have on native wildlife in the Everglades. In total, Florida has seen at least 137 introductions of non-native amphibians and reptiles, more than anywhere else in the world.
“Most people in Florida don’t realize when they see an animal if it’s native or non-native and unfortunately, quite a few of them don’t belong here and can cause harm,” said Kenneth Krysko, Florida Museum of Natural History herpetology collection manager and lead author of a 20-year study published in Zootaxa Sept. 15, 2011, documenting all known introductions to the state from 1863 to 2010. “No other area in the world has a problem like we do, and today’s laws simply cannot be enforced to stop current trends.”
Until about 1940, the introductions were incidental, primarily resulting from the cargo trade. But in the 1970s and ’80s, pet dealers began importing more species to meet the boom in popularity of exotic terrarium animals. The study attributes 84 percent of the introductions to the pet trade, with 25 percent traced to one animal importer.
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.”