Staff & Student News
Bibiana Moncada (image left) from the Universidad Distrital Francisco Jose de Caldas, Colombia, successfully defended her PhD thesis on the systematics, ecogeography, and importance of the lichen genus Sticta in Colombia. Bibiana is one of several graduate students supported through Botany Adjunct Curator and Collections Manager Robert Lücking's NSF grant "Neotropical Epiphytic Microlichens" and is the first PhD student to receive her degree as part of this project. Bibiana's thesis work is being published in three large chapters (phylogeny, ecogeography, and a monograph) and was proposed for a merit degree (corresponding to "cum laude"). For her thesis work, Bibiana studied over 2000 specimens morphologically and close to 600 specimens using molecular data of the ITS barcoding gene, and she could show that the previously recognized 30 species for Colombia actually represent nearly 150 species, a 5-fold increase. Nearly one hundred of these are new to science, which sets a new record for a regional lichen monograph and a world record for macrolichens. The results of Bibiana's study, which were featured in part in Europe's leading journal for scientific dissemination, International Innovation, have impact on the role of the paramo region for human well-being, since paramo regions are important water supplies for urban regions and Sticta lichens serve as water reservoirs influencing the local microclimate. They are also capable of fixing atmospheric nitrogen and contribute to the nutrient cycle and plant growth in paramos. Based on the results from Bibiana's thesis work, Robert and MacArthur Associate Chair Thorsten Lumbsch (Botany) have assembled an international team to tackle the evolution and importance of Sticta lichens on a global scale.
On December 7 Assistant Curator Ken Angielczyk (Geology) presented an invited talk in the Department of the Geophysical Sciences at the University of Chicago entitled “Everett Olson, Ecosystem Robustness, the Tragedy of the Commons, and Tetrapod Herbivores.” The talk explored some of the evolutionary implications of work that Ken has been doing on how food web structure can promote or inhibit the spread of disturbances in a community, and what effect the evolution of tetrapod herbivores in the Early Permian Period of Earth history may have had on the robustness of food webs.
Assistant Curator Corrie Moreau (Zoology/Insects) traveled to Ann Arbor, Michigan December 5–7 to give the invited Hubbell Memorial Lecture in the Department of Ecology and Evolution at the University of Michigan. Corrie shared her research including why ants are one of the most numerically and ecologically dominant groups of terrestrial organisms on the planet. To understand the factors that have shaped their ecological and evolutionary success, it is important to consider not only their evolutionary history and the time frames involved, but how mutualisms and associations ants have with other insects, plants and bacteria have contributed. Through a combination of methods in evolution and ecology, including molecular systematics, comparative genomics, diversification analyses, biogeographic range reconstruction, diet experiments and microbiome pyrosequencing, scientists are beginning to understand the importance of both the evolutionary and ecological timescales on ant diversity.
Research & Publications
Research Associate Jake Esselstyn (Zoology/Mammals) visited the Field Museum this week to work with Associate Curator John Bates (Zoology/Birds) and Neguanee Collections Manager Bill Stanley (Zoology/Mammals) on an NSF-funded project investigating the relationships among taxa of old world shrews. Adjunct Curator Julian Kerbis (Zoology/Mammals), currently in Uganda, is also a collaborator on this project. The study‘s primary goal is to elucidate the evolutionary history and biogeography of one of the most diverse and yet morphologically consistent mammal groups. This research is only possible because of the African and Asian collections assembled by Mammal Division scientists.
Jake sent some preliminary results to John and Bill. John used Google to search for solutions to printing long complex trees, and found a program written by Associate Curator Rick Ree (Botany). The resulting tree is printed on the 18 pages (pictured at left with John, Bill and Jake in Stanley Field Hall). Several potential taxa new to science are represented on these pages.
Postdoctoral researcher Sittiporn (“Kong”) Parnmen (Botany) published a paper with Chair and MacArthur Associate Curator Thorsten Lumbsch and Collections Manager and Adjunct Curator Robert Lücking (both Botany) entitled “Phylogenetic Classification at Generic Level in the Absence of Distinct Phylogenetic Patterns of Phenotypical Variation: A Case Study in Graphidaceae (Ascomycota)” in the online journal PLoS ONE available here. In this article they address the problem with the results of molecular studies that should be translated into a classification of genera. Their approach allows them to choose among classification alternatives and to identify a classification that best reflects morphological differences. They demonstrate the use of this method with a group of mostly tropical lichens, called the Chapsa clade in the family Graphidaceae, and describe four new genera in this group of lichen-forming fungi.
Regenstein Postdoctoral Fellow Mark Golitko (Anthropology) published an article with Lucas Kellett (University of Maine at Farmington) and Brian S. Bauer (University of Illinois at Chicago) in Journal of Archaeological Science entitled “A provenance study of archaeological obsidian from the Andahuaylas region of southern Peru.”
Curator Gary Feinman and Adjunct Curator Linda Nicholas (both Anthropology) conducted an analytical study this fall focused on obsidian and prehispanic patterns of exchange in the Valley of Oaxaca, Mexico. Obsidian, or volcanic glass, was highly valued by Mesoamericans before the arrival of the Spanish as it could be chipped to create a sharp cutting edge in a world without metal tools. For archaeologists, obsidian has a valuable property in that each volcanic source is distinguished compositionally by a different suite of trace elements, which if detected allow researchers to match pieces from archaeological sites to the source where the stone was mined originally. There are approximately 25-30 obsidian sources in Mesoamerica.
Feinman and Nicholas implemented this study by bringing a portable x-ray fluorescence device from the Laboratory of Anthropology at The Field Museum with them to Oaxaca. The portable XRF provides a relatively new technology to measure the trace elemental composition of each sample of obsidian. Previously, only about 500 pieces of obsidian from sites pertaining to all prehispanic phases had been sourced from the Valley of Oaxaca. The small number of such samples was unfortunate since there are no known obsidian mines in the entire State of Oaxaca, so the sourcing of Oaxaca obsidian with firm temporal contexts provides a potential basis to examine shifting patterns of exchange between that region and the rest of Mesoamerica. Yet, archaeological studies in the Valley of Oaxaca have turned up tens of thousands of pieces of obsidian. The small number of previously-sourced pieces is a function of several factors, notably that earlier sourcing technologies tended to be destructive, expensive, and/or at a minimum required export of obsidian samples out of Mexico.
During the fall analytical study, roughly 5000 pieces of obsidian were sourced (see header image and image above left). Although the great majority of these samples came from El Palmillo and the Mitla Fortress, two sites in the area excavated by Feinman and Nicholas, smaller quantities of obsidian were studied from 12 other sites in the region. To expand their sample, Feinman and Nicholas received significant help from local scholars and administrators of Mexico’s Institute of Anthropology and History.
Preliminary analysis, amply assisted by Postdoctoral Scientist Mark Golitko (Anthropology), has revealed that at least 11 different obsidian sources (and possibly as many as 14) from across the cultural area are represented in this Valley of Oaxaca sample. Work is underway to assess spatial and temporal patterning in these data, although preliminary examinations look highly promising.
Fieldwork & Collections
From Dec 1–2, Resident Graduate Student Nate Upham (University of Chicago and Zoology/Mammals) attended MastoSerra 2012 (see above image), a conference organized by mammalian biologists from Rio de Janeiro held in the mountains of Parque Nacional da Serra dos Órgãos about two hours from Rio. There are an incredible 21 separate laboratories studying mammalian ecology and evolution in the state of Rio de Janeiro, so the conference attracted over 100 students and faculty. The high density of mammalogists in Rio is linked to the generous mentoring of Dr. Rui Cerqueira, who has trained 30 masters and 13 doctoral students at the Universidade Federal do Rio de Janeiro since 1983. Earlier this year, Dr. Cerqueira was awarded an Honorary Membership from the American Society of Mammalogists (ASM), and in an exchange coordinated by MacArthur Curator Bruce Patterson (Zoology/Mammals), Nate presented Dr. Cerqueira with a pewter medallion from his ASM award. It was a surprise ceremony and the honor was received with emotion and gratitude (see photo: Rui center with his students in attendance—quite a legacy to celebrate!).
On December 3, back at the Museu Nacional in Rio de Janeiro, Nate completed a week of work in their extensive collection of Atlantic Forest mammals. He was photographing several species of spiny rats from Brazil that are not found in North American collections. Earlier on his trip, Nate presented an invited talk to the Biology Department at the Universidade Federal do Espirítu Santo in Vitória, Brazil. His talk was entitled, “Diversificação molecular e morfológica de Neotropical roedor linhagem maior (Caviomorpha: Octodontoidea)” and given in English with Portuguese slides to a diverse group of students and faculty.
Public Education & Media Coverage
On December 14, C&R Media Interns Jared Berent and Kate Webbink released a new The Field Revealed entitled What’s in a Name? Species names are important, and much like the species they refer to, names often change over time. Taxonomists have been struggling to keep track of them all since the origins of natural history. Binomial nomenclature, the standardized way in which scientists name species, was a major breakthrough. That breakthrough is about 250 years now, though, and it's a tall order to keep track of 250-years' worth of new names, new species, and information about those species. Dr. Ellinor Michel from the International Commission on Zoological Nomenclature recently visited the Field Museum in November to discuss ZooBank, a new online archive of zoological species names.