University of Michigan
Department of Ecology and Evolutionary Biology

Running cockroaches start to recover from being shoved sideways before their dawdling nervous system kicks in to tell their legs what to do, researchers have found. These new insights on how biological systems stabilize could one day help engineers design steadier robots and improve doctors' understanding of human gait abnormalities.

In experiments, the roaches were able to maintain their footing mechanically – using their momentum and the spring-like architecture of their legs, rather than neurologically, relying on impulses sent from their central nervous system to their muscles.

"The response time we observed is more than three times longer than you'd expect," said Shai Revzen, a U-M assistant professor of electrical engineering and computer science, as well as ecology and evolutionary biology. Revzen is the lead author of a paper on the findings published online in Biological Cybernetics. It will appear in a forthcoming print edition.

To gather detailed information about the roaches' gait, the researchers utilized a technique Revzen developed several years ago called kinematic phase analysis. It involves using a high-speed camera to constantly measure the position of each of the insects' six feet as well as the ends of its body. A computer program then merges the continuous data from all these points into an accurate estimate of where the roach is in its gait cycle at all times. The approach gives scientists a more detailed picture than measuring the timing of footfalls – a common metric used today to study gait.

In kinematic phase analysis, the signals are converted into a wave graph that illustrates the insect's movement pattern. The pattern only changes when the nervous system kicks in. How do the researchers know this? In a separate but similar experiment, they implanted electrodes into the legs of seven cockroaches to measure nerve signals.

Robot makers often look to nature for inspiration. As animals move through the world, they have to respond to unexpected disturbances like rocky, uneven ground or damaged limbs. Revzen and his team believe that patterns in how they move as they adjust could give away how their machinery and neurology work together.

"The fundamental question is, 'What can you do with a mechanical suspension versus one that requires electronic feedback?" Revzen said. "The animals obviously have much better mechanical designs than anything we know how to build. But if we could learn how they do it, we might be able to reproduce it."

More than 70 percent of Earth's land surface isn't navigable by wheeled or tracked vehicles, so legged robots could potentially bridge the gap for ground-based operations like search and rescue and defense.

For human gait analysis, Revzen and colleagues said their noninvasive, high-resolution kinematic phase approach could be valuable in the biomedical community.

"Falls are a primary cause for deterioration in the elderly," Revzen said. "Anything we can do to understand gait pathology and stabilization of gait is very valuable."

These experiments were funded by the National Science Foundation and conducted at the University of California, Berkeley, before Revzen came to U-M. Shortly before Revzen joined U-M, he received a Young Investigator Award from the Army Research Office for related research.

U-M News Service press release and video

Increasing evidence suggests that loss of Earth’s biological diversity will compromise our planet’s ability to provide the goods and services societies need to prosper.

Read the opinion piece in The Scientist (Feb. 20, 2013) by Brad Cardinale, an associate professor in the Department of Ecology and Evolutionary Biology and in the School of Natural Resources and Environment. He is director of the school's Conservation Ecology Program and teaches courses in conservation, restoration ecology, and ecosystem services. He is also an elected member of the International Council for Science's research program DIVERSITAS.

The article ends, “We are taking the very genes and species that have made Earth an inhabitable and biologically productive planet over the past 3.8 billion years, and we are lining them up on the edge of a cliff from which there is no return. If the ever growing human population is to continue to prosper, we must better appreciate how our own well-being is directly linked to the great variety of life that is the most striking feature of our planet.”

Gregory Dick is one of three U-M professors who are among the 126 early-career scientists and scholars from the United States and Canada selected as 2013 Alfred P. Sloan research fellows.

Dick is assistant professor of ecology and evolutionary biology and earth and environmental sciences.

The awards were announced Thursday, Feb. 14, 2013 by the Alfred P. Sloan Foundation. The fellows, who are nominated by their peers and chosen by a panel of senior scholars, each receive $50,000.

Dick's research program focuses on the interactions between microbiology and geochemistry in deep-sea hydrothermal vent plumes. Funding from the Sloan Foundation will help support deep-sea experiments to test hypotheses regarding the metabolisms of major microbial groups and their roles in the global carbon cycle.

"I'm ecstatic," Dick said. "To me, this award is recognition that the work we've been doing is important and exciting.

"One of the things this award is going to allow me to do is extend support to some post-docs in my lab who are working on some really novel aspects that are difficult to get funded by the National Science Foundation because they are somewhat high-risk," Dick said. "For example, one project is to develop computer models of microbial communities, which is a little bit crazy, because microbial communities are very complicated things."

The Sloan program seeks to recognize the achievements of outstanding young scholars in science, mathematics, economics and computer science. Past recipients of Sloan Research Fellowships have gone on to win Nobel prizes, Fields Medals (mathematics), and John Bates Clark Medals (economics).

The Alfred P. Sloan Foundation is a philanthropic, not-for-profit grant-making institution based in New York, established in 1934 by Alfred Pritchard Sloan Jr., then-president and chief executive officer of General Motors Corp.

On the U-M Gateway

U-M News Service press release

Environmental scientist Joel D. Blum has been awarded the 2013 Clair C. Patterson Award from the Geochemical Society for the development and application of innovative techniques that have enhanced the understanding of the behavior of mercury in the environment.

The Patterson Award is given annually for a breakthrough of fundamental significance in the field of environmental geochemistry. It is the Geochemical Society's highest honor in the discipline of environmental geochemistry.

Blum is the Arthur F. Thurnau and John D. MacArthur Professor of Earth and Environmental Sciences and a professor in the Department of Ecology and Evolutionary Biology. His research group developed methods to make high-precision measurements of mercury isotope ratios and has applied this tool to a wide range of research problems in biogeochemistry and environmental science.

The techniques have been used, for example, to obtain the first-ever chemical "fingerprints" of the element mercury in the environment, enabling researchers to directly link exposure in animals and humans to specific sources of pollution.

Mercury is a naturally occurring element, but more than 2,000 tons are emitted to the atmosphere each year from human-generated sources such as coal-fired power plants, small-scale gold-mining operations, metals and cement production, incineration and caustic soda production. Health effects on humans include damage to the central nervous system, the heart and the immune system. The developing brains of fetuses and young children are especially vulnerable.

The Patterson Award is named for Clair Cameron Patterson, who is known for two major scientific accomplishments. Using lead and uranium isotope measurements from the Canyon Diablo meteorite, he calculated the age of the Earth to be 4.55 billion years—a figure far more accurate than those that existed at the time and one that has remained unchanged for more than 50 years.

Next, Patterson turned his attention to the study of lead contamination in the environment. His research led to a re-evaluation of the growth in lead concentrations, from industrial sources, in the atmosphere and in the human body. Following a protracted campaign by Patterson against lead contamination, lead additives in gasoline and lead solder in food cans were banned.

While Blum was a graduate student at the California Institute of Technology, he got to know Patterson and was influenced by his research and his dedication to environmental activism.

"My research is in some ways motivated by, and similar to, several different pioneering studies that Patterson did," Blum said. "So it's a great honor to receive this award, named for one of the giants in the field of environmental geochemistry."

U-M News Service press release

Fabien Duveau, a postdoctoral fellow and evolutionary biologist, has been awarded the prestigious European Molecular Biology Organization Fellowship.

The 12-month fellowship award of over $40,000 is from EMBO, headquartered in Heidelberg, Germany. The award, which recognizes excellence in life sciences, is sponsored by 27 governments, which contribute to the General Program of the European Molecular Biology Conference.

Duveau works in the lab of Professor Patricia Wittkopp. His main interest is to understand how biases in mutational spectrum can influence evolutionary trajectories, with a particular focus on gene expression in the budding yeast Saccharomyces cerevisiae. “To this end, I am trying to identify and characterize the properties of hundreds of mutations previously isolated in the Wittkopp lab that affect the transcription level of a focal gene (TDH3),” Duveau said. “This powerful experimental approach will also be extended to the analysis of additional yeast promoters to unravel gene properties affecting mutational spectra. This work will provide a better understanding of the evolutionary role of mutations, which will be instrumental for improving models of regulatory evolution. In a broader scope, the study of mutational spectra in unicellular eukaryotes should also help to predict mutation-driven phenotypes in human such as birth defects or cancers.”

Ancient carbon trapped in Arctic permafrost is extremely sensitive to sunlight and, if exposed to the surface when long-frozen soils melt and collapse, can release climate-warming carbon dioxide gas into the atmosphere much faster than previously thought.

University of Michigan ecologist and aquatic biogeochemist George Kling and his colleagues studied places in Arctic Alaska where permafrost is melting and is causing the overlying land surface to collapse, forming erosional holes and landslides and exposing long-buried soils to sunlight.

The team, led by Rose Cory of the University of North Carolina, reported its findings in an article  published online Feb. 11, 2013 in the Proceedings of the National Academy of Sciences. EEB graduate student Jason Dobkowski is a co-author of the paper.

"What we can say now is that regardless of how fast the thawing of the Arctic permafrost occurs, the conversion of this soil carbon to carbon dioxide and its release into the atmosphere will be faster than we previously thought," Kling said. "That means permafrost carbon is potentially a huge factor that will help determine how fast the Earth warms."

Watch for an EEB research feature coming soon.

U-M News Service press release

Caption: Professor George Kling at a landslide thermokarst on a glacial headwall near Toolik Lake, Alaska. As permafrost ice melts, the soil collapses and either creates an erosional hole in the tundra or a landslide such as this one. These features are called thermokarst failures. Photo courtesy of George Kling.

Senate Bill 78 would prevent the Department of Natural Resources from setting aside an area of land specifically for the purpose of maintaining biological diversity (in essence, to protect the variety of plants and animals that live in an area). If the bill passes, the DNR could not make or enforce a rule to do that. That oversight would come from the Legislature.

Professor Bradley Cardinale (EEB/School of Natural Resources and Environment) said areas with more biodiversity offer all kinds of benefits for people and wildlife. He said this bill doesn’t consider benefits.

“And all of the language is essentially arguing that we need to give people higher priority to have access to the land, to be able to extract resources from the land.”

Consider attending the hearing on SB 78 to testify, scheduled for 9 a.m., Thursday, Feb. 14, 2013 in Room 210 Farnum Building, 125 W. Allegan Street, Lansing, Mich. Or you can email your Michigan state senator to express your opinion on SB 78 in case it comes up for vote. This bill is similar to one Senator Casperson introduced last fall, SB 1276. Sign up for committee notices on the Michigan Legislative website.

Listen to the podcast of "The Environment Report" on Michigan Radio

The LSA website’s slideshow features winning entries from EEB’s recent photo contest, highlighting fieldwork amid global wonders. Glimpse a pufferfish in Japanese waters, see Alaskan ice masses, and view barnacles along Hong Kong’s rocky shores. Don’t miss this special feature with accompanying photo captions.

Watch for all the submitted images coming soon to a screen in the lobby of the Shapiro Undergraduate Library!

Previously on the U-M Gateway and in the Record Update, Feb. 26, 2013.

Soon, you might have to shell out more dough for your cuppa joe. Professor John Vandermeer was interviewed by CNBC and Southern California Public Radio about a coffee rust fungus that’s severely affecting coffee crops.

“The fungus is devastating crops in Central America, which has become one of the most important growing regions in the world,” according to Southern California Public Radio. “It's the worst outbreak in more than 40 years and it's estimated that this year's crop could be cut by a third or more.”

"The real question in my mind is whether this disease is going to be a continual problem like this not just this year, but in the foreseeable future," said Vandermeer. If it becomes a longer term problem, coffee lovers can expect to pay higher prices.

Read the article and listen to the podcast on S. California Public Radio.

Read coverage by CNBC. Listen for Vandermeer on the BBC World Service program, “Science In Action,” Thursday, Feb. 7, 2013 at 12:32 p.m. (1932 GMT).

New York Times Green blog, Environment section.

Previously, on the U-M Gateway.

U-M News Service press release

Working beneath the towering oaks and maples on the U-M’s central campus Diag, undergraduate researchers and their faculty adviser helped explain an observation that had puzzled insect ecologists who study voracious leaf-munching gypsy moth caterpillars.

The caterpillars, which defoliate and sometimes kill stands of trees in the Upper Midwest and the Northeast, are especially fond of oaks, but sugar maple trees appear to be relatively resistant to the European pest.

Biologists wondered whether the caterpillars shun sugar maples in part because their leaves are less nutritious than the leaves of other trees. To find out, U-M biochemist Ray Barbehenn and several of his undergraduate research assistants compared the protein quality of red oak and sugar maple leaves from trees on the Diag.

What they found runs counter to conventional wisdom on the topic, which states that protein quality in leaves differs significantly from species to species. Instead, Barbehenn and his students found that the amino acid composition of the proteins in red oak and sugar maple leaves is strikingly similar – so similar, in fact, that they could not be distinguished during the spring, when gypsy moths do most of their feeding.

However, the researchers found that protein is more abundant in oak leaves than in maple leaves. Instead of differences in protein quality, we showed that maple trees have lower quantities of protein than oak, partly explaining why they are less nutritious than oak leaves," said Barbehenn, an associate research scientist in the Department of Ecology and Evolutionary Biology and the Department of Molecular, Cellular and Developmental Biology. The amount of essential amino acids in oak leaves was 30-42 percent higher than the EAA content of maple leaves in the spring and summer.

"These results help us understand the nutritional reasons why insects perform better or worse on different species of plants. This kind of information is needed in agriculture and forestry to improve the resistance of plants to insect pests," he said. "In the short term, though, this is basic research that is driven by the curiosity of ecologists to understand nature better."

The team's findings will be published in an upcoming edition of the journal Oecologia. Authors of the journal article are Barbehenn and two of his former undergraduate research assistants, Joseph Kochmanski and Julie Niewiadomski. Barbehenn has worked with more than 40 undergraduate research assistants since 2000.

Read the Oecologia paper

U-M News Service press release

On the U-M Gateway, click on the featured photos.

Captions: (top) U-M student research assistants Grace Lee (left) and Cara Mozola cut sugar maple leaves on the Diag as part of a study of leaf protein quality and gypsy moth caterpillars. Credit: U-M Undergraduate Research Opportunity Program.

A gypsy moth caterpillar. Credit: Richard Lindroth.