ASU News - Life Science + Life Science + Life Science

Bacterial ‘ropes’ tie down shifting Southwest

mcoulomb — Mon, 16 Nov 2009 00:00:00 -0700

Researchers from Arizona State University have discovered that several species of microbes (cyanobacteria), at least one found prominently in the deserts of the Southwest, have evolved the trait of rope-building to lasso shifting soil substrates.

These tiny filamentous cyanobacteria are typically found in the environment as multicellular single strands or threads. Though known as pioneers in the biostabilization of soils, scientists have long puzzled over the factors that control and promote the twisting of some species’ individual threads into thick cords sometimes inches in length.

Ferran Garcia-Pichel and Martin Wojciechowski, researchers in ASU’s School of Life Sciences in the College of Liberal Arts and Sciences, examined genetic markers of rope-makers, relating them to shear stress, soil particle size and friction velocity (linked to erosion) to develop an understanding about the relationship between bacterial behavior, evolutionary fitness and environmental effectors.

The results of their study, published Nov. 17 in the journal Public Library of Science (PLoS) ONE, revealed that rope-building cyanobacteria, typically found in fine, sandy desert soils, marine subtidal stromatolites and coastal sand flats, are able, because of their larger size, to hog-tie sand grains and resist eroding wind and fluid at velocities that would typically wash away their thread-like relatives.

"While forming thick ropes seems to have apparent disadvantages, such as limiting access to light or nutrients, bundling-up actually turns out to be, literally, like throwing your neighbor a life-line," Garcia-Pichel says.

Wojciechowski adds: “These microbes rope-building attributes have added to their success as the true Western pioneers.”

Garcia-Pichel believes that it was environmental effectors that led to the selection of genetic traits to promote rope-building. Phylogenetic analyses performed by the researchers have further shown that the evolution of the trait occurred separately in three different genera; an example of convergent evolution, rather than a tie to a single common rope-building ancestor.

In the desert, the initial stabilization of topsoil by rope-builders promotes colonization by a multitude of other microbes. From their interwoven relationships arise complex communities known as “biological soil crusts,” important ecological components in the fertility and sustainability of arid ecosystems.

Research shows impacts from airborne nitrogen

mcoulomb — Thu, 05 Nov 2009 10:06:37 -0700

The impact of airborne nitrogen released from the burning of fossil fuels and widespread use of fertilizers in agriculture is much greater than previously recognized and even extends to remote alpine lakes, according to a study published Nov. 6 in the journal Science.

Examining nitrogen deposition in alpine and subalpine lakes in Colorado, Sweden and Norway, James Elser, a limnologist in the School of Life Sciences at Arizona State University, and his colleagues found that, on average, nitrogen levels in lakes were elevated, even those isolated from urban and agricultural centers.

The article “Shifts in lake N:P stoichiometry and nutrient limitation driven by atmospheric nitrogen deposition” presents experimental data from more than 90 lakes. The researchers’ collaboration also revealed that nitrogen-rich air pollution has already altered the lakes’ fundamental ecology.

“This is because plant plankton or phytoplankton, like all plants, need nitrogen and phosphorus for growth,” Elser says. “Inputs from pollution in the atmosphere appear to shift the supplies of nitrogen relative to other elements, like phosphorus.”

The increase in the availability of nitrogen means that growing phytoplankton in lakes receiving elevated nitrogen deposition are now limited by how much phosphorus they can acquire. Elser says that this is important because “we know that phosphorus-limited phytoplankton are poor food – basically ‘junk food’ for animal plankton, which in turn are food for fish.”

“Such a shift could potentially affect biodiversity,” he adds. “However, we don’t really know because unlike in terrestrial systems, the impacts of nitrogen deposition on aquatic systems have not been widely studied.”

Elser’s collaborators include researchers Tom Andersen and Dag Hessen from the University of Oslo; Jill Baron of the United States Geological Survey and Natural Resource Ecology Laboratory at Colorado State University; Ann-Kristin Bergström and Mats Jansson with Umeå University, Sweden; and Koren Nydick of the Mountain Studies Institute in Colorado, in addition to Marcia Kyle and Laura Steger, who are members of his own group in ASU’s College of Liberal Arts and Sciences.

Hessen, a well-known limnologist, and Elser have had a long-standing collaborative relationship, looking not only at nitrogen deposition but also zooplankton nutrition and a broad range of stoichiometric studies. Elser met Bergström at a conference at Umeå University and discovered that she had performed similar experiments in Sweden.

“By combining these studies we were able to achieve a more global picture of how nitrogen was impacting a broad range of lakes and come to firmer conclusions about effects of deposition,” Elser says.

Elser and Hessen hope to expand on these findings and have a pending grant proposal with the Norwegian government. In addition, Elser says he hopes to perform similar studies in China “where atmospheric nitrogen pollution is extremely high,” but, as yet, unstudied.

Elser has built a career around asking questions about energy and material flows in ecosystems, and traveling all over the world to find answers.Understanding the balance of phosphorus, carbon and nitrogen in systems forms the backbone of Elser’s worldview, known as “stoichiometric theory.” His pioneering studies have jumpstarted new research approaches, insights into nutrient limitation, trophic dynamics, biogeochemical cycling, and linkages between evolutionary and ecosystem processes. This study was supported by the National Science Foundation.

Engineering new approaches to cancer research

jkullman — Mon, 26 Oct 2009 10:19:34 -0600

Deirdre Meldrum, dean of the Ira A. Fulton Schools of Engineering, is a key member of a team leading a new Arizona State University research center that will embark on a novel approach to understanding and treating cancer.

Meldrum directs the Center for Ecogenomics at ASU’s Biodesign Institute. The center will play a role in work for the new Center for Convergence of Physical Science and Cancer Biology at ASU.

It’s one of 12 Physical Sciences-Oncology Centers being supported by the National Cancer Institute, a part of the National Institutes of Health, to pursue development of new methods of arresting tumor growth and metastasis in the fight against cancer.

Research at the Center for Ecogenomic focuses in part on the study of the fundamental mechanisms governing the birth, growth and decline of human cells with the aim of better understanding and finding ways to combat the most widespread diseases and other threats to human health.

ASU’s new cancer research center will use technology developed in Meldrum’s ecogenomics lab, specifically a medical imaging technology called cell CT. Pioneered by researcher Roger Johnson and Alan Nelson, it enables true three-dimensional computed tomography imaging of individual cancer cells.

For more information visit: http://asunews.asu.edu/20091026_ASUcancer

ASU scientists' research on honey bees featured in ‘Science’

mcoulomb — Thu, 22 Oct 2009 19:54:38 -0600

Two Arizona State University researchers, Robert Page and Gro Amdam, are the subject of a feature article in the Oct. 25 issue of the journal Science, which traces their collaboration, discoveries and extensive published works on the reproductive traits and social life history of honey bees.

Page is a professor and founding director of the School of Life Sciences. Amdam is an associate professor in both the School of Life Sciences and Norwegian University of Life Sciences.

As detailed in Science, the collaboration between Page and Amdam has led to the synthesis of the “reproductive ground plan hypothesis,” and catalyzed understanding of how genes and hormones might control social roles and longevity. Their focus on the role of the ovary in honey bee colonies has contributed insight as to how genetically related colony members partition the labor of the colony between raising young bees, nest construction, food processing, and foraging for pollen or nectar.

In her article, journalist Elizabeth Pennisi notes that Page and Amdam’s hypothesis has provided a framework and tools to study division of labor, which now “converges on two genes that may explain both ovary size and behavior.”

Amdam, expanding on observations made in the Science article, notes that “Fundamentally, our work is about how complex social behavior evolves – which gives a history and an understanding of how behavior is regulated today.

What emerges from our hypothesis and data is that social behavior is not ‘new,’ it can be built from old mechanisms – behavioral mechanisms that were present before the organism developed sociality,” she adds.

The ASU researchers believe that their reproductive ground plan hypothesis has fueled their research programs, a result of its accessibility for experimental testing: genetically, molecularly, physiologically and behaviorally, and that it “can serve as a looking glass for scientists that work with other social organisms.”

Amdam and Page have published 16 papers together in a range of journals and captured two covers of the journal Nature in 2006. Their collaborative work has also been featured in and on the covers of Naturwissenschaften and Bioessays in 2007, while Amdam’s team in Norway received the same honor in Functional Ecology in 2008 and the Journal of Experiment Biology in 2009. Page and Amdam’s most recent publication in the journal Genetics, published online and featured on the cover in October, highlights their study of the genetics of ovary size. Both researchers were also part of the Honey Bee Genome Sequencing Consortium that published the genome of the honey bee in 2006.

Page is a highly cited author with more than 200 publications centered on Africanized bees, genetics and evolution of social organization, sex determination and division of labor in insect societies. He has received numerous awards and honors, including election to the German Academy of Sciences Leopoldina, the American Academy of Art and Sciences, the Brazilian Academy of Science and the American Association for the Advancement of Science. Page, professor emeritus and former chair of the Department of Entomology at the University of California, Davis, has been intrigued by how complex social behavior evolved since he earned his doctorate there in 1980. In 2004, he was recruited to develop the School of Life Sciences in the College of Liberal Arts and Sciences at ASU. As its founding director, he has established the school as a platform for discovery in the biomedical, genomic, and evolutionary and environmental sciences. In addition, he founded the Social Insect Research Group and ASU Honey Bee Research Facility, which has attracted top researchers in social insect studies to ASU. Page was also named a fellow of the Wissenschaftskolleg zu Berlin (Wiko) or Institute for Advanced Study, where he is leading a working group on social insect evolution.

Amdam was selected as a Pew Scholar in the Biomedical Sciences by the Pew Charitable Trusts and a Young Outstanding Researcher by the Research Council of Norway in 2007. Starting out as a theoretician who built computer simulations of social interactions, Amdam has moved on to make key discoveries in the genetic, physiological and behavioral mechanisms underlying division of labor, caste development and has advanced understanding around the evolution of social life strategies, including aging, in social insects. Her work produced the first “knockdown” adult bee where gene expression was experimentally changed, and her research team in Norway discovered how honey bee aging can be a function of behavior, rather than age itself. She has published 46 articles since her first paper appeared in 2002. Her work, primarily using the honey bee as a model organism, has been published in professional journals as varied as Nature, Science, Experimental Gerontology, Proceedings of the National Academy of Science (PNAS), Behavioural Brain Research, Public Library of Science (PLoS) Biology, Animal Behavior and Advances in Cancer Research. Amdam joins Page as a Fellow at the Wissenschaftskolleg zu Berlin in 2010, with her focus on the role of epigenetic mechanisms in social behavior.

To hear more about these researchers:

Science Studio podcast with Robert Page: http://sols.asu.edu/podcasts/index.php?year=2007#Vol_18

Ask A Biologist podcast for K-12 with Gro Amdam: http://askabiologist.asu.edu/podcasts/index.html#Amdam

James Elser joins ranks of elite faculty

mcoulomb — Wed, 21 Oct 2009 15:17:56 -0600

Editor’s Note: This profile is one in a series that highlights Arizona State University’s 2008 and 2009 Regents’ Professors. The Regents’ Professor honor is the most prestigious faculty award at the university. Click here to view the complete list of awardees.

In another lifetime, ASU Regents’ Professor James Elser might have pursued his childhood passion for a life devoted to faith, as a priest, taking confessions rather than conducting experiments. However, his early desire to discover answers to deep questions took him into a career in science instead.

As a professor in the School of Life Sciences at Arizona State University, Elser has taken fields of study in new directions, both physically and experimentally. In the pursuit of the yet-to-be-known about the evolution, the flow of energy and materials in ecosystems and the impact of human activity in nature, Elser has traveled from the frozen stretches of Antarctica and the alpine lakes of Norway and Colorado to the Mongolian grasslands of China and the hot springs of Yellowstone National Park and Cuatro Cienegas, Mexico.

A scholar and adventurer, Elser examines the balance of the elements carbon, nitrogen and phosphorus in organisms and ecosystems and tries to understand their potential role in ecological and evolutionary dynamics. This focus emerges from Elser’s pioneering world view, known as the theory of “biological stoichiometry.”

“We started our studies examining plankton, nutrient cycling, food quality and element ratios in different zooplankton species,” Elser says. “We came to the realization that some of the fundamental understanding about plankton could be applied to all living things, from fruit flies to tumors.”

In addition to co-writing a book considered a “milestone in ecology” (“Ecological Stoichiometry: the Biology of Elements from Molecules to the Biosphere”) with Robert W. Sterner, his colleague at the University of Minnesota, Elser has penned or co-written more than 150 research publications on topics as wide ranging as ecosystem nutrient limitation, trophic dynamics, biogeochemical cycling, life history evolution, proteomics, cancer and infection. His highly cited work has appeared in venues as diverse as Science, Nature, Nature Reviews Microbiology, Ecology, Limnology and Oceanography, American Naturalist, Genome, Ecology Letters, Ecosystems, and Proceedings of the National Academy of Sciences.

Even more importantly, Elser has communicated his joy of discovery and creative approach to science to others.

As an ASU life sciences professor in the College of Liberal Arts and Science since 1990, Elser has taught more than 12,000 students and directly mentored 33 undergraduates, 10 graduate students, and 11 others in his laboratory. His “Biology 100” course is legendary for “weird days.”

“Weird” was the watchword for Fridays, when Elser would come to class armed with claims from pop culture and pseudo science, such as “Nostradamus predicted the attack on 9/11” or “Therapeutic touch can cure cancer.” He would deconstruct the claims, using the scientific method and look for real evidence behind the “weird.”

Elser melds an inquiry-based and question-driven approach that taps into students’ natural curiosity and desire to answer questions. His teaching style promotes life skills that extend beyond biology, as he challenges students to discover how scientific reasoning can apply in their daily lives and help them make sense of an increasingly complex world where science has major ramifications for political, cultural and personal decision-making.

Elser also is highly active in building integrative research collaborations within ASU and abroad. For example, one project’s study – in partnership with Valeria Souza, a professor with Universidad Nacional Autónoma de México – of a unique series of ancient hot springs and ecosystems in Cuatro Cienegas in Chihuahua, Mexico – has led to the discovery of new species of microbes and fundamental insights into how phosphorus limitation has shaped their evolution and that of the food webs that they support. His work with Souza has greatly increased the national and international profile of this unique landscape, including added support from the governor of Coahuila, the secretary of the environment, and Mexican President Phillipe Calderon.

Creative approaches and partners also have helped Elser garner millions of dollars in research funding from National Science Foundations, National Aeronautics and Space Administration, and National Institutes of Health.

Elser’s commitment to learning and discovery also extends to the wider community in Arizona. As associate director of the Research and Training Initiative Program in the School of Life Sciences, he has led faculty and students to paint houses for the elderly during the Rock and Roll Paint-Thon, held fundraisers for Chrysalis Shelter for Women and Children, Pappas School for Homeless Children, and Camp Kesem (an ASU undergraduate organization that provides experience for children whose family members have cancer), among others projects. He also has spearheaded the creation of credible, institutional relationships with Arizona Science Center and area public schools, and encouraged his colleagues to reach out, communicate and contribute in ways that outlast a funding cycle. In addition, he created the annual SOLS Takes a Hike community outreach event that puts graduate students and faculty in touch with the public through a series of guided hikes conducted in local parks. This event is now part of ASU in the Community, and has touched the minds and hearts of more than 300 children, families, retirees and ASU alumni.

ASU entities nominated for Innovator of the Year Award

cderra — Tue, 13 Oct 2009 10:31:33 -0600

Two ASU entities – the College of Technology and Innovation on the Polytechnic campus and the School of Life Sciences on the Tempe campus – are finalists for the 2009 Innovator of the Year Award for Academia, which is given out as part of the Arizona Governor’s Celebration of Innovation.

Winner of the award, Arizona’s highest honor for technology innovation, will be named at a banquet on November 19. The award – given to a department or office within an accredited higher education institution that has achieved success through innovation in the past calendar year – is presented by the Arizona Technology Council and the Arizona Department of Commerce.

Two specific ASU projects were highlighted as examples of innovation for each ASU entity. For the College of Technology and Innovation, the process of converting algae into jet fuel is cited; and for the School of Life Sciences, the development of computer software that can compare the genomes of humans and pathogens was cited.

In ASU’s School of Life Sciences, Sudhir Kumar, an ASU professor of biology, recognized early on the importance and usefulness of computer analysis of genetic data. His research group pioneered development of methods and discovery tools for the analysis of DNA of humans and their pathogens. Over the past year, Kumar, who also is director of the Center for Evolutionary Functional Genomics at ASU’s Biodesign Institute, and his group have developed and refined tools for the computational analysis of DNA data (called MEGA software) and for mining scientific literature to build a tree of life scaled to time (TimeTree Web tool).

These two software tools have proven to be quite popular. The MEGA software for comparative genomics has been cited in more than 3,000 publications annually and the TimeTree of Life Web tool, launched this year, has been accessed 30,000 times in the past few months. Its widespread use includes a targeted educational component and is accessible to everyone.

“Around the world, thousands of scientists are studying the evolutionary diversification of life by taking advantage of rapidly expanding DNA genome databases,” said Robert Page, founding director of ASU’s School of Life Sciences. “The genomic software developed by Sudhir Kumar has improved not only the fundamental understanding of the process of evolution but also provided key insights into the evolution of beneficial (e.g. crops) and harmful (pathogens, pests) species.”

The work of Milton Sommerfeld and Qiang Hu, both professors of applied science and mathematics, was highlighted in the College of Technology and Innovation nomination. Sommerfeld and Hu have developed a process that can convert algae into aviation or jet fuel. Last year, Time magazine named the process one of the top innovations in 2008.

Sommerfeld and Hu have been working on algae as a source of renewable fuel for more than 25 years. The technology they developed uses sunlight, waste materials like carbon dioxide in flue gas, and nitrates and phosphates in waste waters as nutrients for growing a renewable algae feedstock that yields oil. The algae biomass residuals yield carbohydrates for ethanol production and proteins for animal feed or organic fertilizer.

“A significant aspect of Sommerfeld and Hu’s research is the holistic nature of their efforts,” said Douglas Green, interim chair of the applied science and mathematics department. “Not only are they interested in lipid production from algal cells, but they continually strive and have been successful in utilizing inputs and products to create a green, sustainable production chain.”

The researchers recently received significant funding for their algae projects and already two spin-off companies have been created from technologies developed in their laboratory.

The Governor’s Celebration of Innovation has become a premier community gathering in Arizona. The November 19 banquet will be held at the Orpheum Theatre in Phoenix.

Spider lab at ASU's West campus frightens, then educates

sdesgeor — Fri, 09 Oct 2009 16:18:51 -0600

“Along came a spider,
And sat down beside her,
And frightened Miss Muffett away.”

Little Miss Muffett, Anonymous

(Editor’s Note: No spiders were harmed in the telling of this story. As the research being conducted is behavioral, it is, as professor Chad Johnson notes, “important we keep them alive.”)

Little Miss Muffett wouldn’t stand a chance in Chad Johnson’s classroom. Being “frightened away” is not an option in the “spider lab” at Arizona State University’s West campus where Johnson is an assistant professor in the New College of Interdisciplinary Arts and Sciences. The lab, after all, is home to thousands of highly venomous Latrodectus hesperus, or Western Black widow spiders.

Spiders. The iconic Halloween creature lives, breeds, cannibalizes its own, and serves as a learning tool for Johnson and his student research assistants, many of whom overcome their fears of spiders simply by getting closer to the eight-legged crawlers and climbers.

Johnson, who joined the faculty in New College’s Division of Mathematical and Natural Sciences in 2006, is well known and well published when it comes to spiders. His research has appeared in such leading journals as Animal Behaviour, Behavioral Ecology, Behavioral Ecology and Sociobiology, and Ethology, and has captured the interest of his students, who can be found counting, feeding, poking and caring for his roomful of black widows on the third floor of the Classroom Lab/Computer Classroom building.

The research Johnson and his students are conducting focuses on how spiders make a living in urban and desert environments. In particular, one ongoing study focuses on the cannibalistic tendencies of spiderlings and how a mother’s body condition might impact her offspring’s rate of cannibalism. It’s a tangled web, indeed, for the young ones, born as many as 250 to a single egg sac. They're brothers and sisters who don’t seem to hesitate before dining on one another.

But first, student researchers must leave their fears at the door.

“I think spiders are frightening to some people because they are so foreign,” says Johnson, who earned his Ph.D. in biology at the University of Kentucky. “They have all those legs, and it is mysterious who they are and what they are. They come out at night, and that plays into people’s fears.

“The more you learn about spiders, the less apprehension you have. Personally, I’m more afraid of snakes, because I don’t understand them.”

For graduate assistants Patricia Trubl and Lindsay Miles, their fears began – like most – at an early age, but have since been allayed as they get up-close and personal with Latrodectus hesperus.

“(Spiders) used to scare the bejeezus out of me,” says Miles, who received her B.S. in biology at ASU last May. “They crawl, and when they get on you, it’s creepy. They bite, which is a health danger. I used to jump out of the way of spiders.”

So how did she come to work in Johnson’s lab, meticulously working a small paint brush around mature adult black widows as large as 15 millimeters in length and 600 milligrams in weight, while gathering more data on their feeding habits?

“(Johnson) said in class one day, ‘I work with black widows and I need volunteers.’"

Her start was designed to ease her into the spiders’ makeshift world.

“I started out doing maintenance and cleaning the spider dishes,” says Miles, who already has her sights set on Ph.D. work in animal behavior following her graduate studies at the West campus. “Then I got involved with an independent study in the lab and started working with the spiders more closely, studying web building and the difference between urban- and desert-dwelling spiders.”

The research is important, she says, and tied to her future career as a research biologist.

“This helps you understand the elements of research,” she says. “You design a project, conduct the study and test it, you analyze the data, and write or publish into a peer-reviewed journal. To take research from the design stage to the publishing stage means that you, as a researcher, are able to think outside the box. It translates to, ‘I have my own ideas, and I can test my own ideas.’”

Meanwhile, Trubl started working in Johnson’s lab in 2007, and it was a close encounter of the wolf spider kind as a youngster that cemented her fear of spiders.

“I was 7 years old when I got bitten by a wolf spider. It was this big,” she says, spreading her arms out wide. “I told my mom that it had pinned me down. It was that scary. Now, logically, I know they’re not that big, but it sure seemed like it at the time.

“I think people are afraid of spiders because they don’t know them, but do know they can hurt you. Parents, too, instill a fear of spiders in you at an early age; they’re always telling you to stay away from spiders. Plus, they’re used as a scary symbol, along with witches and goblins.”

Trubl graduated with a B.S. in life sciences last May. She is currently a teacher’s assistant in a biology lab class at the Tempe campus as she works toward an M.S. in biology.

“I was terrified when I started working in the spider lab, but I didn’t let (Johnson) know,” she says. “It took me 45 minutes to catch my first spider and my hands were shaking for months. Chad told me to just relax. Finally, as I got to know the spiders I realized they are more afraid of me than I am of them; they run the other way when they see me coming. Now, I can catch a spider in 30-60 seconds.”

“This lab and the research work we are doing represent a unique opportunity for students to study and learn,” says Johnson, who visits grade school classrooms to share learning experiences utilizing his eight-legged friends. “It may sound altruistic, but this is what prepares students to take the next step, to reach the next level after graduation.

“Science has the power to explain our world to us, and animals and plants are a part of that world. It’s important we study and know what’s around us.”

Trubl, a mother of a 5-year-old son she is teaching to respect — not fear — spiders, takes a practical approach to the research being conducted by Johnson and company.

“We live in an urban center, and black widows thrive in urban areas,” she says, counting fruit flies as they spill from a tube into a container of baby spiders. “In studying the black widow, we can understand how disturbed environments, such as urbanization, impact species for the short and long term.

“Plus, I’m interested in foraging behavior and sexual selection in invertebrate systems. Studying black widows will allow me to better prepare myself for a Ph.D. program and an eventual college teaching career where I will have my own lab.”

30 years of finches bring evolutionary theory to life

mcoulomb — Thu, 08 Oct 2009 22:38:44 -0600

Kyoto winners to speak at ASU Darwinfest

Peter and Rosemary Grant, Princeton professors emeritus and winners of the 2009 Kyoto Prize for Lifetime Achievement, come to Arizona State University on Oct. 28 to join in ASU’s Darwinfest, as part of the Darwin Distinguished Lecture Series. Their talk about their work with “Darwin’s Finches” starts at 6 p.m. in the Turquoise Ballroom at the Memorial Union on the Tempe campus and will be followed by a book signing.

With more than 35 years devoted to study in the Galapagos Islands, the Grants shared research has delved into questions about natural selection and evolutionary change. Their long-term studies (where the duo tagged thousands of birds — that's more than 20 generations) have allowed the Grants to trace lineages and demonstrate how evolutionary change — revealed through alternations in beak size and shape — can rapidly result via competition for resources and environmental stress. The Grants and their finch studies formed the basis of the novel “The Beak of the Finch: A Story of Evolution in Our Time” penned by Jonathon Weiner, which won a Pulitzer Prize in 1995. Following their talk, the Grants will sign copies of Weiner’s book and their own, titled “How and Why Species Multiply. The Radiation of Darwin’s Finches.”

As the 150th anniversary of Darwin’s book “On the Origin of Species” draws nigh, the last of the distinguished lecture series will be held on Nov. 13 at 2 p.m. in the Life Sciences E-wing, room 104. Noted author Janet Browne, Harvard University Aramont Professor of the History of Science will address “Celebrating Darwin: 1909, 1959 and 2009.”

ASU Darwinfest was developed by School of Life Sciences founding director Robert E. Page, Jr., in collaboration with Quentin Wheeler, VP and Dean of the College of Liberal Arts and Sciences. Designed to bring attention to how bold ideas can transform science, technology and society, ASU Darwinfest has grown to become one of the most significant Darwin celebrations nationally. With more than 33 partners and sponsors, on and off campus, ASU launched the Darwin Distinguished Lecture Series with a visit from E. O. Wilson, The Future of Evolution Lecture Series (held at the Arizona Science Center), and a ASU workshop for public school teachers called “Translating Evolutionary Science into the Public Classroom Workshop.” Emissaries of the New American University, graduate students collaborated from a range of academic units at ASU and hosted festivals, movies, contest, panels and discussions with some of the foremost evolutionary scientists and theorists in the world. Darwinfest also served as a platform for the original and radical science being done on campus. Estimated attendance of core events exceeded 3,600, not including the popular Origins Initiative and lecturers Daniel Dennett and Jay Melosh, hosted by the Beyond Center for Fundamental Concepts in Science. The Darwin Distinguished Lectures have been captured as podcasts, featured by Apple on iTunesU and can be found at http://darwin.asu.edu. For more information about the upcoming talks by the Grants or Browne, contact Margaret.coulombe@asu.edu; (480) 727-8934.

Bird feathers color research on duck nutrition

Mon, 14 Sep 2009 19:37:00 -0600

The wings of many ducks are decorated with intense bands of color, while others are downright drab. Have you ever stopped to think about the significance behind the coloration of birds? Biologist Kevin McGraw has.

McGraw’s laboratory in the School of Life Sciences at Arizona State University delves deep into research that examines pigments and structural color and their link to nutrition in birds – with funding from the National Science Foundation (NSF) and support from postdoctoral fellow Melissah Rowe and University of Rochester undergraduate Alison Ossip-Klein.

McGraw’s research grows out of his interest in understanding how and why animals display the colors that they do. In previous work, for example, he discovered that foods rich in carotenoids – yellow, orange and red pigments found in plants that also function as antioxidants – can directly affect bird coloration and health.

“These studies of carotenoids and color have emerged as an excellent model for testing life-history tradeoffs using a common nutritional currency,” McGraw says.

McGraw’s most recent NSF study examines how pigments in ducks play a role in their vision, health and appearance. McGraw’s group is working with 120 male and female ducks from two waterfowl species; the Mallard (Anas platyrhynchos) and the Northern Pintail (Anas acuta). As part of the experimental regime, the ducks are first fed a low-carotenoid “depletion diet” to flush their systems of these pigments. Then they are divided into six groups and placed on experimental diets that differ only in concentration of xanthophyll carotenoids (like lutein and zeaxanthin, typical yellow components of corn). Once the birds molt and develop their attractive adult colors this fall, McGraw and his team will score coloration, immune system performance and carotenoid accumulation in internal body tissues (like ovaries and eyes) to determine how relatively important these different uses of pigments are.

Ossip-Klein joined McGraw's laboratory by applying to do a summer Research Experiences for Undergraduates (REU) fellowship funded by the federal government and administered in the College of Liberal Arts and Sciences by the School of Life Sciences. “I never worked with birds before, but was curious about sexual selection and coloration in animals and found the topic interesting,” Ossip-Klein says. She was in charge of diet preparation and contributed to regular blood draws (for health assessment) and behavioral monitoring.

“We typically work with ten or more ASU undergraduates in our research each year,” McGraw says. “They become involved through many different routes – as student volunteers, to earn independent-study credit, as hired employees on grants, or as part of our formal research track, the School of Life Sciences Undergraduate Research (SOLUR) program.” To ensure the best fit in his lab, McGraw searches for students “with diverse interests, perhaps having a background in ecology, evolution or physiology or an interest in animal communication, sexual selection, coloration or immunology”.

Ossip-Klein gained a range of skills and experiences working with the ducks, including learning how to handle birds, conducting morphological measurements and video analysis of animal behaviors, and utilizing sophisticated biochemistry equipment, like High Performance Liquid-Chromatography (HPLC), to analyze pigments in food and tissue.

Ossip-Klein also made time during her 11-week stay in Arizona to conduct her own independent project. McGraw says that “it was my and Melissa Rowe’s hope that we could attract a student that would not only assist with our project but also have the maturity and drive to pursue his/her line of research with these birds.” Ossip-Klein chose to explore the role of carotenoids in influencing the flight capacity of ducks. Based on similar work in the field, she hypothesized that ducks exposed to higher concentrations of carotenoids would fly higher and faster. She will be analyzing the data she’s gathered over the course of the next few months.

“Kevin definitely has one of the top labs in the country that deals with animal coloration,” says Australia native Melissah Rowe. Rowe was drawn to McGraw's lab while completing her doctorate at the University of Chicago. McGraw gave a talk there about on colors in songbirds in 2005, and she introduced herself and was soon collaborating with him.

“Understanding the potential tradeoffs of a certain molecule for multiple functions within an organism, and how an organism might prioritize an allocation to one or the other of those competing functions,” is what Rowe says is the most interesting part of this research in McGraw’s laboratory.

Rowe also points out, “Kevin is a very prolific researcher, and is one of the main reasons I chose to come to ASU.”

By: Addie Lenox
School of Life Sciences

Media contact: Margaret Coulombe
(480) 727-8934
margaret.coulombe@asu.edu

Cockroaches advance student’s study of ancient life

Thu, 03 Sep 2009 19:56:32 -0600

Have you ever seen a three-foot dragonfly? Where such gigantic insects once dominated earth, now only diminutive cousins remain. What created these differences? Elyse Munoz, a junior majoring in biology in the College of Liberal Arts and Sciences, had the rare opportunity to directly investigate this question over the summer, while participating in cutting-edge research in the lab of physiologist Jon Harrison.

"In the lab, research experiences provide an internship-type training that let students actually do research, rather than just read or hear about it," says Harrison, a professor in the School of Life Sciences. "They learn practical techniques, as well as ways of thinking critically about the research process. They get to interact on a personal level with faculty, post-doctoral fellows and graduate students, which helps them decide whether this is something they wish to do as a career."

Munoz connected with Harrison through the summer Undergraduate Research Experience program (REU) offered by the School of Life Sciences. The program is just one of a number of undergraduate research programs in the school. Such opportunities are one reason that Munoz, a native of San Antonio, Texas, came to Arizona State University with an award from the Hispanic Scholarship Fund.

“This research program has given me a truly invaluable experience,” Munoz says, “and an amazing opportunity to improve on myself and explore avenues of science that I didn’t even know existed.”

A Barrett Honors College student fueled by a penchant for genetics and a desire to become a surgeon, Munoz discovered the life sciences research program while taking Harrison’s undergraduate course in anatomy and physiology; attending graduate students mentioned there was a summer research opening in the Harrison lab to do research with insects.

Munoz says that while she wasn’t exactly sure what the research entailed, she had enjoyed Harrison’s course. She applied and was accepted.

The summer undergraduate research program links students with mentors and existing grants from the National Science Foundation (NSF). Students receive fellowships and are paid while they learn first hand what research is all about.

The NSF grant on which Munoz works was developed by John VandenBrooks, a post-doctoral fellow in the Harrison laboratory. Jennifer Hale, another life sciences undergraduate, is also working on this project. The goal of VandenBrook’s research is to understand how oxygen affects the body size of insects related to those that existed in the Paleozoic era. A second goal is to determine whether the dimensions of insect tracheae (breathing tubes) can be used to estimate oxygen levels of the prehistoric earth.

Why the link between oxygen and size? Models developed by scientists have suggested that levels of oxygen in earth’s atmosphere have undergone some major shifts over time. For example, oxygen is believed to have reached 31 percent during the Paleozoic era (today it is 21 percent), followed by a massive decline to as low as 13 percent in the Mesozoic era. The gigantic insects occurred at the same time as the oxygen peak, suggesting that changes in atmospheric oxygen enabled and then eliminated these giants.

How can one measure the oxygen in prehistoric atmospheres? The idea that Munoz, Hale, VandenBrooks and Harrison pursue is that the dimensions of insect’s tracheae can provide a key. They are measuring the effect of different oxygen levels on the dimensions of the bodies and tracheal tubes of German roaches. The reason the cockroach is interesting is that the species have lived for such a long time and existed during time periods of both high and low oxygen and persist still today. To study them, Munoz and Hale spent this summer rearing cockroaches in tanks that contained different oxygen levels. They measured the insects’ growth, and then took them to the Argonne National laboratory in Chicago, which operates an X-ray Synchrotron. There, Munoz, Hale and VandenBrooks peered inside the cockroaches and collected images that will enable them to document the effect of oxygen level on the dimensions of the cockroaches’ tracheae. The researchers also imaged many insect fossils that have been preserved in amber, an optically clear, petrified pitch from ancient plants. They hope to verify a method for estimating the oxygen content of ancient atmospheres from the ratio of trachea tubes size to body size in insects. If successful, this will be a major advance for biology and geology.

Taking on summer research study is a commitment. Munoz worked roughly 40 hours a week, but the returns on her investment have been immeasurable. “Working with the graduate and post doctoral students has been amazing. They have so much to teach, and most importantly are willing and wanting to help you advance and succeed,” says Munoz of her colleagues.

A typical day of research in the laboratory for Munoz started with checking the oxygen and nitrogen levels in the tanks along with ensuring the ROXY (the lab’s oxygen regulating system) was running effortlessly. The start of her week was dedicated to the care of the lab’s 500 cockroaches. Munoz and Hale changed their water tubes and replenished their food, if needed, just as if they were family pets. With a laugh, Munoz admits that the general maintenance, such as attempting to put the roaches into their containers, was her least favorite part of the research. In addition to caring for her research subjects, Munoz performed imaging, data collection and analysis.

“Sometimes it’s just as satisfying to see that you were wrong as it is to see that you were correct in your hypothesis and your predictions,” says Munoz about her research results.

In addition to her work examining oxygen levels in cockroaches, Munoz will gear up to do research on dragonflies. She will examine the effect of atmospheric oxygen level on the growth and size of dragonfly larvae: a study that will turn her summer research into a long-term project that extends into the fall. Results from her researches may ultimately support the generation of an academic paper.

Munoz hopes that as she continues to learn new skills in Harrison’s lab, she will ultimately come to design her own experiments, possibly focusing on the genetics in these insects. “The experience has been fantastic,” Munoz says. “I recommend it to all ASU students.”

To find out more about the School of Life Sciences undergraduate research opportunities, visit: http://sols.asu.edu/ugrad/research_experiences.php

By: Addie Lenox
School of Life Sciences

Media contact: Margaret Coulombe
(480) 727-8934
margaret.coulombe@asu.edu