October 4, 2006, 4:34 AM CT

Morganella Pyriformis

Morganella pyriformis is a puffball. The mature fruiting body of the fungus bursts open and releases the spores, after some physical force has been applied. I've been known to help a few of these along.

Previous to 2003, this fungus was known as Lycoperdon pyriforme. It has since been moved out of the genus Lycoperdon based on molecular evidence and morphological difference to other members of the genus. No longer is the evocative common name suggested by Tom Volk a literal translation of the genus name. A different common name, pear-shaped puffball, is perhaps more proper. After all, the epithet pyriformis does mean "in the form of Pyrus (pear)". However, I'll personally use the one proposed by Tom, because I know I'll never forget it.

Tom's article also has a story about the results of deeply inhaling the spores of puffballs (don't do it). Illustrations and descriptions of Morganella pyriformis are available from both Mykoweb and Michael Kuo's MushroomExpert.com.........

Posted by: Erica      Permalink         Source

October 3, 2006, 9:58 PM CT

Uncoveing Roots Of DNA Secrets

DNA's simple and elegant structure - the "twisted ladder," with sugar-phosphate chains making up the "rails" and oxygen- and nitrogen-containing chemical "rungs" tenuously uniting the two halves - seems to be the work of an accomplished sculptor.

Yet the graceful, sinuous profile of the DNA double helix is the result of random chemical reactions in a simmering, primordial stew.

Just how nature arrived at this molecule and its sister molecule, RNA, remains one of the greatest - and potentially unsolvable - scientific mysteries.

But Vanderbilt biochemist Martin Egli, Ph.D., isn't content to simply study these molecules as they are. He wants to know why they are the way they are.

"These molecules are the result of evolution," said Egli, professor of Biochemistry. "Somehow they have been shaped and optimized for a particular purpose".

"For a chemist, it makes sense to analyze the origin of these molecules".

One particular curiosity: how did DNA and RNA come to incorporate five-carbon sugars into their "backbone" when six-carbon sugars, like glucose, may have been more common? Egli has been searching for the answer to that question for the past 13 years.

Recently, Egli and colleagues solved a structure that divulges DNA's "sweet" secret. In a recent issue of the Journal of the American Chemical Society, Egli and colleagues report the X-ray crystal structure of homo-DNA, an artificial analog of DNA in which the usual five-carbon sugar has been replaced with a six-carbon sugar.........

Posted by: Janet      Permalink         Source

October 3, 2006, 9:49 PM CT

Myths about species abundance

A new report finds little empirical evidence to support a widely held ecological assumption that species are most abundant near the centers of their geographic ranges and decline in abundance near the ranges' edges.

"When we reviewed data from published studies that looked at species abundance at multiple sites across a range, we found almost no evidence that supported the so-called 'abundant-center hypothesis' and strong evidence that contradicted it," said Raphael D. Sagarin, associate director for oceans and coastal policy at Duke University's Nicholas Institute for Environmental Policy Solutions.

"This is troubling," Sagarin said, "because a lot of current thinking on ecological and evolutionary issues -- including how species will respond to climate change, how to identify probable locations of pest outbreaks, how genetic diversity is distributed among populations and where to locate habitat preserves -- has been based on the hypothesis".

The validity of these ideas now needs to be re-examined using empirical studies, he said.

Sagarin is one of the principal authors of the report, which appeared in the September 2006 issue of the journal Trends in Ecology and Evolution. Other authors are Steven D. Gaines of the University of California-Santa Barbara's Marine Science Institute and Department of Ecology, Evolution and Marine Biology; and Brian Gaylord of the University of California-Davis's Bodega Marine Laboratory and Section of Evolution and Ecology.........

Posted by: Janet      Permalink         Source

October 3, 2006, 9:33 PM CT

Fisheries Linked To Decline In Albatross Population

Fishermen caught and killed about 1 percent of the world's waved albatrosses in a year, as per a new study by Wake Forest University biologists.

"If that happens every year, that is not sustainable," said Jill Awkerman, a Wake Forest graduate student who is the lead author of the study published online Sept. 26 in the journal Biological Conservation. "In a matter of decades, you could be talking about extinction".

Awkerman's research shows the waved albatrosses are unintentionally killed when caught in fishing nets or on fishing hooks, but are also intentionally harvested for human consumption.

She worked with David Anderson, professor of biology at Wake Forest, on the study. Since 1999, Anderson and his research team have studied survival rates of waved albatrosses on Española Island in the Galapagos Islands, located off the coast of Ecuador. Española is a small island where almost all of the waved albatrosses in the world nest and breed.

Identification bands from 23 waved albatrosses killed in 2005 were returned to the scientists by fishermen. The scientists put bands on a total of 2,550 albatrosses, so almost one out of every 100 birds is being killed unintentionally or intentionally by fishermen.

As part of the study, the scientists and his colleagues in Peru also surveyed 37 major fishing communities to investigate albatross interactions with fisheries in the main areas where they forage for food off the Peruvian coast. They sent observers out on fishing vessels to find out what happens when fishermen encounter the giant seabirds. The observers observed that some albatrosses became tangled accidentally in submerged gillnets. Eventhough some of the birds caught in nets could be released, fishermen often killed them for food instead. The fishermen also intentionally caught albatrosses on baited hooks.........

Posted by: Kelly      Permalink         Source

October 3, 2006, 5:20 AM CT

Reintroducing Megafauna To North America

Dozens of megafauna (large animals over 100 pounds) such as giant tortoises, horses, elephants, and cheetah went extinct in North America13,000 years ago during the end of the Pleistocene. As is the case today in Africa and Asia, these megafauna likely played keystone ecological roles via predation, herbivory, and other processes. What are the consequences of losing such important components of America's natural heritage?.

In the recent issue of The American Naturalist, a group of 12 ecologists and conservationists provide a detailed proposal for the restoration of North America's lost megafauna. Using the same species from different locales or closely related species as analogs, their project "Pleistocene Rewilding" is conceived as carefully managed experiments in an attempt to learn about and partially restore important natural processes to North American ecosystems that were present for millennia until humans played a significant role in their demise 13,000 years ago.

"Over the past 30 years, more and more evidence suggests that if we lose large animals from ecosystems, they often collapse and biodiversity, along with society, are the ultimate losers," says Josh Donlan (Cornell University). "For millions of years, large animals were the norm all over the world we should start thinking about reintroducing these large animals and restoring these important processes back to ecosystems."........

Posted by: Kelly      Permalink         Source

October 3, 2006, 5:16 AM CT

Chilly Bugs At Bottom Of The World

The larvae of Antarctic midges never stop producing special proteins that minimize environmental stress, allowing them to withstand a range of intense environmental conditions in one of the world's harshest environments.

Researchers observed that adult midges (Belgica antarctica) lose their ability to continually express these protective heat-shock proteins. Instead, like most animals, adult midges produce these proteins only when they are stressed. The discovery currently appears in the online edition of the Proceedings of the National Academy of Sciences.

The proteins help defend the larval midges against environmental stresses including temperature changes as well as changes in water, oxygen and pH levels, said David Denlinger, the study's lead author and a professor of entomology at Ohio State University.

"They've somehow figured out a way to maintain a level of these heat-shock, or stress, proteins and still make proteins that are vital for growth and development," he said.

This mechanism seems to offer the larvae protection during their two-year life span, most of which is spent encased in ice.

All animals, including humans, make heat shock proteins, but normally they only do so during times of extreme physical stress. Curiously, adult midges don't express these proteins all the time - only during periods of extreme environmental stress. Yet when most insects express stress proteins, it temporarily compromises the production of other proteins, Denlinger said.........

Posted by: Kelly      Permalink         Source

October 2, 2006, 10:10 PM CT

How did bilaterally symmetric flowers evolve?

How did bilaterally symmetric flowers evolve from radially symmetric ones? To address this important question, geneticists Francisco Perfectti and Juan Pedro M. Camacho, and ecologist Jos M. Gmez (Universidad de Granada, Spain) explored how different flower shapes affected plant fitness in natural populations of Erysimum mediohispanicum, a Mediterranean herb. Their findings would be reported in the recent issue of The American Naturalist.

The scientists observed that plants bearing bilaterally symmetrical flowers were more visited by pollinators and had higher fitness, measured by both the number of seeds produced per plant and the number of seeds surviving to the juvenile stage, than plants with radially symmetric flowers.

"This study reveals that natural selection can play a key role in the evolution of flower bilateral symmetry," says Camacho. "Our data also suggest that it is possible to understand the evolution of complex forms by means of microevolutionary analyses, as complementary tools to those coming from developmental genetics".........

Posted by: Erica      Permalink         Source

October 1, 2006, 8:56 PM CT

Big Welcome For A Big Cat

A feline ambassador from Pakistan made his debut in the Himalayan Highlands of the Bronx Zoo on September 25, following an historic ceremony that united the Pakistani and U.S. governments. Endangered snow leopard cub Leo was transferred to the Bronx Zoo this past summer after he was discovered orphaned in the wild, unable to fend for himself.

Click here to read more about the expedition and diplomatic collaboration that led to Leo's relocation.

First lady of Pakistan Sebha Musharraf was among the honored guests to officially welcome Leo. "Wildlife is among our greatest resources," she said. "It provides both beauty and a discovery of the natural world around us. Leo is a most fitting wildlife ambassador, representing both Pakistan and his species. It is our hope that he will inspire others to care".

Assistant Secretary of State for Oceans, Environment and Science Claudia A. McMurray also attended the welcome ceremony. She commented, "Today we celebrate the arrival of this beautiful snow leopard cub as a symbol of hope for the global effort to save endangered wildlife. I am particularly pleased that diplomacy between the United States and Pakistan played a key role in making this accomplishment possible".

The 14-month-old male cub will remain at the Bronx Zoo until an appropriate facility can be constructed in Pakistan. As a world leader in snow leopard care-and the first zoo in the Western Hemisphere to exhibit these big cats, in 1903-the Bronx Zoo will provide a secure refuge for the growing cub.........

Posted by: Kelly      Permalink         Source

October 1, 2006, 8:53 PM CT

Opportunity For Conservation

Arctic Alaska contains one of the last great wildlife spectacles in North America. Breeding birds from all over the world-from every continent and every ocean-come here to rear their young in the highly productive summer on the tundra wetlands. In the entire circumpolar Arctic, the Teshekpuk region contains some of the most diverse, productive, and abundant populations of birds.

Birds are not the only fauna attracted to this Arctic haven. The Teshekpuk caribou herd, at 45,000 strong, calves its young here. Grizzly bears, wolves, wolverines, and musk ox thrive in the area. Lemming populations surge periodically. Arctic fox, red fox, weasels, and ground squirrels all call Teshekpuk home.

The Wildlife Conservation Society has been studying wildlife in this region for the past two summers. From our remote field camp located a few miles south of the Teshekpuk Lake shore, we have watched as a number of different species of shorebirds gather to nest and raise chicks. Waterfowl are also abundant, and we have observed large populations of eider, geese, and swans.

Yet a number of of these birds face an uncertain future. The remote haven of Teshekpuk is not immune to the human footprint: Teshekpuk Lake is part of the National Petroleum Reserve-Alaska (NPR-A). At 23.5 million acres, NPR-A is the largest single piece of public land in the United States. The reserve envelops most of western arctic Alaska and its vital wetlands.........

Posted by: Kelly      Permalink         Source

October 1, 2006, 8:49 PM CT

Endangered Western Gray Whale

Ten prominent international researchers will monitor the status of the critically endangered Western Gray Whale population in the Northwest Pacific and provide ongoing independent advice to a consortium of companies developing oil and gas reserves in the whale's summer feeding grounds, off Sakhalin Island in the Russian Far East.

The new long-term Western Gray Whale Advisory Panel, convened by the World Conservation Union (IUCN) brings together independent scientific expertise to inform the decisions of oil and gas companies operating in the marine waters off Sakhalin Island and other interested stakeholders. In particular, the Panel will focus on the Sakhalin II oil and gas project being developed by Sakhalin Energy Investment Company Limited (Sakhalin Energy) and due to commence in spring 2007. Sakhalin Energy is a consortium of companies including Royal Dutch Shell and Japanese companies Mitsui and Mitsubishi Corporation.

The World Conservation Union is convening the Panel in response to the findings of an independent report, published in 2005, on the impacts of the Sakhalin II project on the whale population and following consultation with the oil industry and the conservation community.

"This Panel will help to incorporate long-term scientific findings into the design and management of oil and gas operations in the region, thereby contributing to the conservation and recovery of one of the world's critically endangered giants," said Carl Gustaf Lundin, Head of the IUCN Global Marine Programme.........

Posted by: Kelly      Permalink         Source