Temeles’ research on coevolution of Heliconia plants and carib hummingbirds in the Lesser Antilles is featured in the new exhibit, “Butterflies and Plants: Partners in Evolution,” which opened this February at the National Museum of Natural History (NMNH) in Washington, D.C. Temeles described co-evolution as the “reciprocal adaptation between two species.” The exhibit is featured as one of the museum’s permanent displays as opposed to a seasonal exhibit.
“Part of the exhibit consists of an indoor butterfly garden featuring many tropical butterflies from Central and South America as well as their food plants,” Temeles explained. “The other part of the exhibit consists of displays of research on co-evolution, featuring my work on hummingbirds and flowers, and other research on leaf-cutter ants and their symbiotic fungus, and monarch butterflies and their milkweed food plants.” The exhibit “is really the most evolution-focused hall in the museum,” he said.
Temeles collaborated with John Kress, curator of botany at the NMNH. They observed that variation in H. bihai and H. caribaea flowers on the islands of St. Lucia and Dominica suggested co-evolution corresponding to differences within the same hummingbird species particular to each of the two islands. “The complete reversal in the pattern of polymorphism in the Heliconia species combined with a reversal in the direction of flower size and shape between islands is very convincing evidence that the plants have adapted to the birds,” he said.
Temeles is currently in Dominica continuing field research. “My current research is finding evidence that the birds have adapted to the plants,” he said. “Using a molecular evolutionary history prepared by researchers at Berkeley, I’ve determined that none of the relatives of the purple-throats has as dramatic differences in bill curvature or bill length, supporting the hypothesis that the bills of purple-throats evolved to match the flowers of the heliconias they visit.”
Hood received funding for a five-year program studying the mechanism of DNA hybridization. “Hybrids have a problem in that they are trying to combine DNA with divergent structures into a new organism,” he explained, “and that organism has to figure out how to segregate that information. We’re trying to figure out how hybrids overcome these serious limitations of genetic instability.”
Hood has started his research with startup funds provided by the College. He conducts many experiments in the McGuire Life Sciences Building greenhouse. He says that the grant will expand research opportunities for undergraduates at the College. “The funding will provide money for materials and for summer research opportunities and travel,” he explained. “It will also allow for short-term visits by my collaborators and by graduate students and post-docs from their labs which will help to contribute to the intellectual atmosphere in the lab.” Hood added that one student had already visited and that another would be visiting early in April. “I really like those visits—they really add a lot of energy and bring in new ideas.”
The research might help answer questions about the nature of hybridized viruses. “Several of the major influenza pandemics in history were likely due to the combination of different lineages of the influenza virus,” Hood said. “What we’d like to know is whether their extreme negative impact was a result of how they combined.”
The long-term nature of the research allows for compounded results. “Over five years, we’ll be able to carry through generations of evolutions and we’ll be able it quantify the change in virulence,” he said. “Hybrids tend to be highly variable and it’s that variation among the offspring that natural selection acts upon. Even over the course of half a dozen or a dozen generations you can start to see the evolutionary trajectories in things like virulence.”
Miller and Levin received supplemental funding to continue ongoing research on the evolutionary genetics of the plant genus Lycium. Miller and Levin will travel with Julian Damasek ’09 in preparation for his senior thesis, as well as to collect research materials for a Hughes summer research fellow.
“The Chinese Lycium species include the healthful Goji berry, commonly sold dried or as a juice. You can even buy the berries plain or covered in chocolate at the local Whole Foods,” Levin explained. “For centuries in China this species has been cultivated for its medicinal properties, and our Chinese collaborator, Dr. Ying Wang of the Wuhan Botanical Garden and Institute of Botany, has focused her research on this very important species.”
Levin said that the necessity to study the Chinese species of Lycium was highlighted in the research of Joshua Shak ’06. “Members of this genus are found around the world, with hot spots of diversity in southwestern North America, southern South America, and southern Africa. Further, we know that Lycium must have dispersed via birds circa three to five million years ago from the Americas to Africa and Asia. By including the Chinese Lycium species in our studies, we will be able to better understand the dispersal patterns of Lycium around the world,” she said. “In particular, using various molecular tools we will be able to determine whether Lycium dispersed from the Americas to Africa first or to Asia first.”
The trip to China will allow Miller and Levin to fill in a hole in their current data set. “As Professor Miller and I have collected Lycium around the world, in all major areas except Asia, we are especially excited to travel to China and be able to add these valuable missing pieces of data to our research,” Levin explained.