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Published: December 17, 2012

Ants of the rainforests of South America. Why are some species only found in some places?

Stephanie Ware, Research Assistant II, Integrative Research Center
2009 REU Intern Elizabeth Loehrer

ELIZABETH LOEHRER

Senior Molecular Biology major at Loyola University

REU Mentor: Dr. Corrie Moreau (Assistant Curator, Zoology/Insects)

Symposium Presentation Title: Patterns of Diversification in South American Pheidole:  A Molecular Approach (Arthropoda: Hexapoda: Insecta: Hymenoptera: Formicidae)

Symposium Presentation Abstract: Though the Amazon is known to be a rich and diverse ecosystem, much of the origin and evolution of the Amazonian biota is still unclear.  Using the most speciose ant genus, Pheidole, as my study system, I tested two of the Amazonian origin of species hypotheses, specifically I examined the river barrier hypothesis and the uprising of the Andes hypothesis.  The two hypotheses suggest that speciation events occur in accordance to the formation of natural barriers (e.g. a major river or mountain range respectively) that would prevent two populations from mating and thus lead to diversification (Haffer 2008, Cracraft & Prum 1988). My supervisor, Dr. Corrie Moreau collected Pheidole specimens from various locations in Ecuador, Peru, and Venezuela prior to the commencement of my project. I extracted the DNA from ninety-five specimens and amplified two different genes, EF-1α-F2 and COI.  I used the bioinformatics program, Sequencher® to perform a multiple sequence alignment of my data and TNT® and DNApars® to construct molecular phylogenetic trees of Pheidole.  I then examined the correlation between branching patterns on the tree and the geographic collection site of each specimen to determine the validity of the river barrier hypothesis and the uprising of the Andes hypothesis.  Initial findings with the EF-1α-F2 data did not reveal definitive patterns between geographic location and speciation events, particularly due to multiple polytomies within the tree. Finishing the data set for COI as well as amplifying additional genes may improve tree resolution, which would allow for a better analysis of the connection between diversification and geographic barriers.

Original Project Description: The rainforests of South America are home to thousands of ant species, but what are the historical reasons why some species are found in some places and not others? Several hypotheses have been suggested to explain speciation in the Neotropical rainforests. Using DNA and ants collected from Ecuador and Peru we will be able to test some of these ideas.

Research methods and techniques: Interns will receive training in DNA extraction, PCR, and sequencing in the Museum's core genetics facility, the Pritzker Laboratory and the DNA Discovery Center. They will participate in data collection, assembly and phylogenetic analysis, and be introduced to concepts surrounding the estimation of phylogeny and its uses in studying systematics, evolution, and biogeography.


Stephanie Ware

Stephanie Ware is currently a research assistant in the Division of Insects currently working with Dr. Petra Sierwald. She also works with Mary Hennen in the Division of Birds monitoring the Peregrine Falcon (Falco peregrinus) populations in Illinois.

Stephanie started volunteering at the Field Museum in 1998, working with Curator John Bates in the Bird Division. In 1999, John Bates hired her as a research assistant. After that project finished in 2007, she went to work for Carl Dick in the Division of Insects helping him to complete his work on the museum's Bat Fly collection. She spent a great deal of time generating images for the Bat Fly portion of the Diptera Taxonomy Database. When Carl left for University of Kentucky in 2009, she continued her imaging work in the Insect Division. In the intervening years, she has imaged hundreds specimens, mostly types, from the rove beetle (Staphylinidae), ant and myriapoda collections.

Stephanie began working with the Chicago Peregrine Program in 2006.  Initially, she monitored the Metropolitan Correctional Center nest in downtown Chicago.  Over time, her duties have expanded to include other nests in the metro region, emphasizing the identification of nesting adults.  In March of 2007, Stephanie created a group called Midwest Peregrine Falcons on the photo sharing website Flickr with the goal of providing a place for photographers across the country to submit their photographs of peregrine sightings in the Midwestern United States. She also has many of her own peregrine photos on Flickr as well.