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ISU professor and student biology researchers recognized at international conference

August 6, 2009

An Indiana State University faculty member, a recently-graduated doctoral student and an undergraduate student garnered an award during the annual meeting of the Animal Behavior Society.

More than 500 researchers, hailing from 23 countries, gave presentations at this scientific conference, which was held in Pirénopolis, Brazil, June 21-26.

Diana Hews, ISU associate professor of biology, senior biology major Brittani Gardner and Maria Thaker, a former doctoral student with Hews, received the Founder's Award for their research poster presentation "Fluctuating asymmetry of hormonally-mediated traits in the lizard, Sceloporus undulatus."

Thaker, who grew up in Singapore, received her Ph.D. in biology from ISU in May 2009. Thaker is now a post-doctoral researcher at School of Biological and Conservation Sciences at the University of KwaZulu-Natal in Durban, South Africa.

Gardner, of Glen Ridge Ill., became involved in the research as part of her Research Capstone project, an optional research component of the biology undergraduate degree at ISU. Gardner is a pre-veterinary student and is in the ISU Honors Program.

Conferences are important for students to attend, according to Hews, because

Their research focused on asymmetry, which is when a characteristic deviates from perfect left-right symmetry of the body.

"Many humans have asymmetry in leg length," Hews said as an example. "Fluctuating asymmetry (FA) is when it is random as to which side is bigger."

Hews and her colleagues studied fluctuating asymmetry in the size of color patches on the eastern fence lizards. Hews' research has shown that these patches are used in signaling to other male lizards in this species. Other work by Hews documented that sex steroid hormones play key roles during the development and expression of these signaling traits. For this study, Hews and colleagues measured color patch sizes and how the sizes for each patch differed on the left sides versus right sides of the body.

Researchers are typically interested in the fluctuating asymmetry of animal traits because it can reflect the environment that an animal experienced when it was developing. This environment can include the mother's womb, the egg or the environment of the juvenile, and thus the development of embryos and juveniles can be affected by changes in this environment, Hews said.

"Nutrition is an important environmental effect, but there are more subtle ones, such as temperature for reptiles and birds, exposure to various chemicals in the womb or egg, and many of these effects can be considered stressful," Hews said. "Researchers are also interested in possible genetic differences among individuals in how resistant their developmental program is to these environmental challenges."

To study fluctuating asymmetry in the lizard color patches, the researchers captured adult lizards from wooded sites on US Forest Service property in the Land-Between-the Lakes area of Kentucky, and then took high-magnification images. Detailed analyses of the digital images revealed that individuals from sites of recent logging showed significantly higher levels of fluctuating asymmetry than animals from non-logged areas. Further, traits that were subjected to early hormonal control showed more fluctuating asymmetry than those traits on which hormones have effects in the adult stage.

"Surprisingly little work has compared the amount of fluctuating asymmetry for traits that have known differences in developmental mechanisms," Hews said.

Thaker was one of 25 students selected to receive a travel award to attend the conference in South America. In addition, she was one of only 12 students selected to present their research orally in the prestigious Warner Clyde Allee Best Student Paper Symposium. Entrants must be graduate students or have recently-minted doctoral degrees, and are chosen to participate in the oral component of the competition based on a seven-page synopsis of the research.

"Giving an Allee talk with other doctoral students was the most appropriate and fun way for me to culminate my graduate years," Thaker said. "Unlike other talks, which are allocated 15 minutes, Allee competitors have 30 minutes to present their work. For most of us, this was more of an opportunity to present results from five years of research than it was a competition."

Thaker's entry in the Allee Competition dealt with the role that stress hormones can play in memory and learning. Although much laboratory research has examined these relationships in humans and rodents, Thaker used a novel experimental approach in a wild animal species. She demonstrated that blood levels of the stress hormone corticosterone show a short-term spike following an encounter with a novel stressor, and that this initial spike facilitates learning and memory during subsequent encounters with the stressor.

Two of Thaker's dissertation chapters have been published this year as papers, both co-authored with Hews and Lima, one in the journal Animal Behaviour and one in Hormones and Behavior.

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Contact: Diana Hews, Indiana State University, associate professor of biology, at 812-237-8352 or dhews@isugw.indstate.edu

Writer: Jennifer Sicking, Indiana State University, assistant director of media relations, at 812-237-7972 or Jennifer.Sicking@indstate.edu

Photo: http://isuphoto.smugmug.com/photos/612656436_Ukfv5-L.jpg

Cutline: Diana Hews, ISU associate professor of biology, accepts the Founders Award during the Animal Behavior Society annual meeting. Courtesy photo

Photo: http://isuphoto.smugmug.com/photos/612656433_SiQEP-L.jpg

Cutline: Coauthors Maria Thaker and Diana Hews after receiving the Founders Award for their poster presentation at the 46th Annual Meeting of the Animal Behavior Society, held this June in Pirénopolis, Brazil. Coauthor Brittani Gardner is not pictured. Courtesy photo

Story Highlights

An Indiana State University faculty member, a recently-graduated doctoral student and an undergraduate student garnered an award during the annual meeting of the Animal Behavior Society.

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