Department of Ecology, Evolution, and Organismal Biology

Dr. John Downing speaks at the 30th Congress of the International Society of Limnology

After more than 30 years, one of the largest gatherings of freshwater scientists returned to North America this past August with a host of experts from around the world. As a Plenary Speaker, EEOB's own Dr. John Downing presented "Global Limnology: Up-scaling aquatic services and processes to the planet Earth" which can be viewed at the following website: http://www.sil2007.uqam.ca/media_stream.html.

 

Release of "Secrets of Plant Genomes: Revealed!" Video

With appearances by EEOB Professor and Chair Jonathan Wendel and his lab, Secrets of Plant Genomes: Revealed! makes the study of plants exciting and relevant by showing how learning more about plants can improve our everyday lives.

Video

 

Tobacco genome article published in lastest version of New Phytologist

Authored by Grover, Hawkins, and Wendel, the article entitled "Tobacco Genomes Quickly Go Up In Smoke" appears in the September 2007 issue of New Phytologist.

Full Article

 

Debinski Studies Methods for Improving Prairie Restoration

Dr. Debinski has been studying a variety of methods to improve prairie restoration efforts for pollinators in agroecosystems.  Her work has involved roadside prairie restorations, filter strips adjacent to crop fields, and large-scale prairie restorations.  She has shown that the composition of the plant community in linear habitats such as roadsides and filter strips affects the composition of the pollinator community.  Filter strip width and the height and vertical density of vegetation are important in attracting prairie specialist butterflies.  She has found that large, integrated prairie restoration projects have a higher diversity of butterfly species as compared to isolated restorations.  She has also shown that bee and butterfly responses to landscape are inversely correlated, indicating that these two pollinator groups are responding to two very different microhabitats within agroecosystems.

Her work on reintroducing a rare prairie butterfly is featured in a book entitled "The Prairie Builders: Reconstructing America's Lost Grasslands" by Sneed Collard

 

Breeding for High Voluntary Exercise Levels in Mice Correlated to Evolution in Lifelong Activity Patterns and Lifespan

Anne Bronikowski, along with collaborators at Washington State University, found that breeding for high voluntary exercise levels caused correlated evolution in lifelong activity patters and lifespan.
Male and female mice that were bred for 16 generations for high voluntary wheel-running early in life, continued to run more than control mice until about midlife (20 months). After that, all animals declined in their voluntary running at the same rate to uniformly low levels at the end of life. Mice that were bred for high voluntary exercise and that had wheels attached to their home cages had the longest median lifespan (healthspan). Interestingly, the mice that faired the worst in the experiment were those animals that had been bred for high exercise motivation, but that did not have exercise wheels.

These mice had significantly shorter healthspans than either control animals or their siblings that were housed with exercise wheels.
(Bronikowski et al. 2006, Evolution 60: 1494 - 1508)

 

Long-lived birds teach us new tricks about aging

Birds live about three times longer than mammals of comparable size. Some of the longest-lived sea birds are unusual in having telomeres (caps on the ends of each chromosome) that do not shorten with time, as they do in other animals. The Vleck Lab has found that these birds have high telomerase activity throughout their lives. Telomerase is a special enzyme that maintains telomere length and extends the chromosome’s ability to replicate. Since most animals down-regulate telomerase, presumably as a deterrent against tumor formation, how these long-lived birds avoid cancer is of special interest.

 

Mitochondrial genomic analysis reveals evolutionary relationships within the most ancient group of animals

It is well accepted that efficient conservation, research and economic use of any group of organisms should be based on a resolved phylogeny. Phylum Porifera (sponges) is the most ancient group of multicellular animals that plays an essential role in many benthic communities and is an important target for marine natural products research. Unfortunately, despite much previous research, the evolutionary relationships of sponges have been mostly unresolved. Among many unanswered questions were the most fundamental, including the monophyly of the group, the relationship among and within its three major classes, and phylogenetic relationships within the Demospongiae, by far the largest class of sponges.

The recent work by Dennis Lavrov’s group addressed the question of demosponge relationships using mitochondrial genomic data. Dennis Lavrov and collaborators determined complete mitochondrial DNA sequences from 22 species of demosponges representing all 14 currently recognized orders in this group. They then used mitochondrial gene sequences and gene order data to reconstruct a well-supported phylogeny for the class Demospongiae. The results of this study revealed that the currently accepted classification of demosponges does not reflect their evolutionary relationships and suggested a large amount of hidden morphological and genetic evolution in this group of animals.

 

New Bamboo Species IDed

Two Iowa State botanists and their colleague at the University of North Carolina have discovered a new species of North American bamboo in the hills of Appalachia. It is the third known native species of the hardy grass. The other two were discovered more than 200 years ago.

ISU botanists Lynn Clark and Jimmy Triplett study bamboo diversity and evolution. They first heard about "hill cane" from University of North Carolina botanist Alan Weakley. As soon as they saw it, they knew it was different.

Hill cane differs from the other two native North American bamboo species -- commonly known as switch cane and river cane -- in an important way: It drops its leaves in the fall.

"That's why it was recognized locally as being different," Clark said. "It's pretty uncommon for bamboos to drop their leaves."

Clark should know. She's an internationally recognized bamboo expert. She had previously discovered 74 new species of bamboo.

"All the other new ones came from Central and South America," she said. "It's so exciting to find a new species in our own backyard!"

Her 75th species discovery has been named Arundinaria appalachiana. Clark, Triplett and Weakley recently completed the intricate process botanists are obliged to follow to officially name and describe a newfound species. Following rules laid out in the International Code of Botanical Nomenclature, they prepared a short description of the plant in Latin and a longer one in English, and provided drawings and other information to make a strong case for the recognition of A. appalachiana as a distinct species of bamboo. They submitted their evidence in a manuscript to the scientific journal Sida, Contributions to Botany, convincing the peer reviewers that the bamboo they discovered was new. Their study was published last fall.

There are 1,400 known species of bamboo. Of those, about 900 are tropical and 500 are temperate. The bamboos of North America are found in the Eastern and Southeastern United States, from New Jersey south to Florida and west to Texas. River cane (Arundinaria gigantea) occurs in low woods and along riverbanks. Switch cane (Arundinaria tecta) is found in non-alluvial swamps, moist pine barrens, live oak woods and along sandy margins of streams.

"Most people have no idea that we have native bamboo in the U.S.," Clark said. "But it has been a very important plant ecologically. And there's recent interest in using it for re-vegetation projects because it's native and was used for habitat by so many different animals, especially birds."

Clark and Triplett began looking at the North American bamboos as part of a larger collaboration with botanists worldwide to develop an evolutionary family tree of bamboo species. They're using modern DNA sequencing technologies together with traditional plant taxonomy, which involves observation and description of a plant's form, anatomy, ecology and other characteristics.

"We want to get the big picture of how all the temperate bamboos are related to each other. That means taking inventory of what exists, then comparing notes," Clark said.

They already know that the closest relatives of native North American bamboos are not in Central or South America, but are in East Asia.

"That's a well-known pattern of diversity in plants and animals. Plants known to be closely related that were previously found across a large area of the earth are only in those two areas now. For various reasons, the Eastern U.S. and East Asia are a repository for a lot of diversity," Clark said.

"But we still don't understand exactly how long it has been since our bamboos separated from their Asiatic cousins. And we don't know how we ended up with three species in North America and 500 in East Asia," she said.

Although botanists had previously studied the North American bamboos, no one had done extensive fieldwork to study and collect the plants in the wild, and questions remained as to whether there was really more than just a single species. In 2003, with funding from the National Geographic Society, Clark and Triplett set off for the Southeast to find the switch cane and river cane in their native habitats.

"Once we actually saw the plants in the field, we knew quickly that there were two distinct species," Clark said. "But we kept hearing about a third plant, called hill cane." And as soon as they saw it, they knew it was different.