February 12, 2009, 6:25 AM CT

Seamounts may serve as refuges for deep-sea animals

Over the last two decades, marine biologists have discovered lush forests of deep-sea corals and sponges growing on seamounts (underwater mountains) offshore of the California coast. It has generally been assumed that a number of of these animals live only on seamounts, and are found nowhere else. However, two new research papers show that most seamount animals can also be found in other deep-sea areas. Seamounts, however, do support especially large, dense clusters of these animals. These findings may help coastal managers protect seamounts from damage by human activities.

Tens of thousands of seamounts dot the world's ocean basins. Eventhough some shallower seamounts have been used as fishing grounds, few seamounts have been studied in detail. Davidson Seamount, about 120 kilometers (75 miles) offshore of the Big Sur coast, is an exception. Since 2000, scientists have spent over 200 hours exploring its slopes and peaks using the remotely operated vehicle (ROV) Tiburon.

Two of the expeditions to Davidson Seamount were led by Andrew DeVogelaere of the Monterey Bay National Marine Sanctuary and were funded by the National Oceanic and Atmospheric Administration's Office of Exploration. Other expeditions were funded by the David and Lucile Packard Foundation (through MBARI) and were led by MBARI biologist James Barry, who studies seafloor animals, and by geologist David Clague, who studies undersea volcanoes......... Posted by: Kelly      Read more         Source

February 10, 2009, 6:25 AM CT

No joy in discoveries of new mammal species

In the era of global warming, when a number of researchers say we are experiencing a human-caused mass extinction to rival the one that killed off the dinosaurs, one might believe that the discovery of a host of new species would be cause for joy. Not entirely so, says Paul Ehrlich, co-author of an analysis of the 408 new mammalian species discovered since 1993.

"What this paper really talks about is how little we actually know about our natural capital and how little we know about the services that flow from it," said Paul Ehrlich, the Bing Professor of Population Studies at Stanford.

"I think what most people miss is that the human economy is a wholly owned subsidiary of the economy of nature, which supplies us from our natural capital a steady flow of income that we can't do without," Ehrlich said. "And that income is in the form of what are called 'ecosystem services'-keeping carbon dioxide out of the atmosphere, supplying fresh water, preventing floods, protecting our crops from pests and pollinating a number of of them, recycling the nutrients that are essential to agriculture and forestry, and on and on".

Ehrlich conducted the analysis with Gerardo Ceballos, a professor of biology at the National University of Mexico. They are co-authors of a paper describing the work, scheduled to be published Monday, Feb. 9, in the online early edition of the Proceedings of the National Academy of Sciences........ Posted by: Kelly      Read more         Source

February 10, 2009, 6:23 AM CT

Salamander decline in Central America

The decline of amphibian populations worldwide has been documented primarily in frogs, but salamander populations also appear to have plummeted, as per a newly released study by University of California, Berkeley, biologists.

By comparing tropical salamander populations in Central America today with results of surveys conducted between 1969 and 1978, UC Berkeley scientists have observed that populations of a number of of the commonest salamanders have steeply declined.

On the flanks of the Tajumulco volcano on the west coast of Guatemala, for example, two of the three commonest species 40 years ago have disappeared, while the third was nearly impossible to find.

"There have been hints before people went places and couldn't find salamanders. But this is the first time we've really had, with a very solid, large database, this kind of evidence," said study leader David Wake, professor of integrative biology at UC Berkeley and curator of herpetology in the campus's Museum of Vertebrate Zoology.

Frog declines have been attributed to a variety of causes, ranging from habitat destruction, pesticide use and introduced fish predators to the Chytrid fungus, which causes an often fatal disease, chytridiomycosis.

These do not appear to be responsible for the decline of Central American salamanders, Wake said. Instead, because the missing salamanders tend to be those living in narrow altitude bands, Wake believes that global warming is pushing these salamanders to higher and less hospitable elevations......... Posted by: Kelly      Read more         Source

February 10, 2009, 6:11 AM CT

How an Antarctic worm makes antifreeze

Two BYU scientists who just returned from Antarctica are reporting a hardy worm that withstands its cold climate by cranking out antifreeze. And when its notoriously dry home runs out of water, it just dries itself out and goes into suspended animation until liquid water brings it back to life.

Identifying the genes the worm uses to kick in its antifreeze system can be useful information - similar genes found in other Antarctic organisms are currently being used to engineer frost-resistant crops.

But BYU's Byron Adams, associate professor of molecular biology, and his Ph.D. student Bishwo Adhikari, are carrying on their love affair with microscopic nematode worms for a different reason.

They spent Christmas near the South Pole to help determine how the fate of a half-millimeter worm can actually impact an entire ecosystem, and how that information can serve as an important baseline for understanding climate change's impact on more complex systems, such as a farmer's field in the United States.

Their latest study, published Monday in the journal BMC Genomics, used samples Adams gathered during prior trips to the world's most inhospitable continent. He's lived at McMurdo Station seven times and hitched helicopter rides to gather soil from Antarctica's freezing, bone-dry valleys, where only a handful of microscopic animals can survive. The ones that do make for a convenient laboratory for observing how minor changes in the environment can have a big impact on an ecosystem......... Posted by: Kelly      Read more         Source

February 4, 2009, 11:12 PM CT

Bacteria Jump From Host to Host

All life - plants, animals, people - depends on peaceful coexistence with a swarm of microbial life that performs vital services from helping to convert food to energy to protection from disease.

Now, with the help of a squid that uses a luminescent bacterium to create a predator-fooling light organ and a fish that uses a different strain of the same species of bacteria like a flashlight to illuminate the dark nooks of the reefs where it lives, researchers have observed that gaining a single gene is enough for the microbe to switch host animals.

The finding, reported this week (Feb. 1) in the journal Nature by a team of researchers from UW-Madison, is important not only because it peels back some of the mystery of how bacteria evolved to colonize different animals, but also because it reveals a genetic pressure point that could be manipulated to thwart the germs that make us sick.

"It seems that every animal we know about has microbes linked to it," says Mark J. Mandel, the main author of the study and a postdoctoral fellow in the UW-Madison School of Medicine and Public Health. "We pick up our microbial partners from the environment and they provide us with a raft of services from helping digestion to protection from disease".

In the Pacific, a species of bacteria known as Vibrio fischeri lives in luminescent harmony with two distinct hosts: the diminutive nocturnal bobtail squid and the reef-dwelling pinecone fish. In the squid, which feeds at night near the ocean surface, one strain of the bacterium forms a light organ that mimics moonlight and acts like a cloaking device to shield the squid from hungry predators below. In the pinecone fish, another strain of the bacterium colonizes a light organ within the animal's jaw and helps illuminate the dark reefs in which it forages at night. The fish light organ may also play a role in attracting the zooplankton that make up the pinecone fish's menu......... Posted by: Kelly      Read more         Source

February 4, 2009, 11:09 PM CT

Why Don't More Animals Change Their Sex

Most animals, like humans, have separate sexes - they are born, live out their lives and reproduce as one sex or the other. However, some animals live as one sex in part of their lifetime and then switch to the other sex, a phenomenon called sequential hermaphroditism. What remains a puzzle, as per Yale scientists, is why the phenomenon is so rare, since their analysis shows the biological "costs" of changing sexes rarely outweigh the advantages.

A report by Yale researchers in the recent issue of The American Naturalist says that while this process is evolutionarily favored, its rarity cannot be explained by an analysis of the biological costs vs benefits.

Sequential hermaphroditism naturally occurs in various organisms from plants to fishes. Following four decades of research that established why sex change is advantageous, the question remained why it is rare among animals. In this study, Yale graduate student Erem Kazancioglu and his advisor Suzanne Alonzo, assistant professor of ecology and evolutionary biology, demonstrate that sex change is surprisingly robust against costs.

While the adaptive advantage of sex change is well understood, it is not clear why relatively few animals change sex. As per Alonzo, "An intuitive, yet rarely studied, explanation is that the considerable time or energy it takes to change sex make hermaphroditism unfeasible for most animals"......... Posted by: Kelly      Read more         Source

February 4, 2009, 11:03 PM CT

Did Early Whales Gave Birth on Land?

Two newly described fossil whales--a pregnant female and a male of the same species--reveal how primitive whales gave birth and provide new insights into how whales made the transition from land to sea.

The 47.5 million-year-old fossils, discovered in Pakistan in 2000 and 2004, are described in a paper published Feb. 4, 2009, in the online journal PLoS.

"This stunning discovery reinforces the belief that modern cetaceans originated from terrestrial ancestors," said H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.

Paleontologist Philip Gingerich of the University of Michigan, who led the team that made the discoveries, was at first perplexed by adult female and fetal bones found together.

"When we first saw the small teeth, we thought we were dealing with a small adult whale, but then we continued to expose the specimen and found ribs that seemed too large to go with those teeth," Gingerich said. "By the end of the day, we realized we had found a female whale with a fetus".

It is the first discovery of a fetal skeleton of an extinct whale in the group known as Archaeoceti, and the find represents a new species dubbed Maiacetus inuus. (Maiacetus means "mother whale," and Inuus was a Roman fertility god.)......... Posted by: Kelly      Read more         Source

February 4, 2009, 10:55 PM CT

Largest Prehistoric Fossil Snake

Researchers have recovered fossils from a 60-million-year-old South American snake whose length and weight might make today's anacondas seem like garter snakes.

Named Titanoboa cerrejonensis by its discoverers, the size of the snake's vertebrae suggest it weighed 1,140 kilograms (2,500 pounds) and measured 13 meters (42.7 feet) nose to tail tip.

A paper describing the find appears in this week's issue of the journal Nature.

"At its greatest width, the snake would have come up to about your hips," said geologist David Polly of Indiana University, who identified the position of the fossil vertebrae, which made an estimate possible. "The size is pretty amazing. We went a step further and asked, how warm would the Earth have to be to support a body of this size?".

Smithsonian Tropical Research Institute geologist Carlos Jaramillo and University of Florida vertebrate paleontologist Jonathan Bloch discovered the fossils in the Cerrejon Coal Mine in northern Colombia, and investigated what the snake's environment might have been like.

Paleontologist Jason Head of the University of Toronto, the Nature paper's main author, made an estimate of Earth's temperature 58 to 60 million years ago in an area encompassed by modern-day Colombia......... Posted by: Kelly      Read more         Source

February 2, 2009, 6:13 AM CT

New class of genes found in mammals

A research team at the Broad Institute of Harvard and MIT and Beth Israel Deaconess Medical Center has uncovered a vast new class of previously unrecognized mammalian genes that do not encode proteins, but instead function as long RNA molecules. Their findings, presented in the February 1st advance online issue of the journal Nature, demonstrate that this novel class of "large intervening non-coding RNAs" or "lincRNAs" plays critical roles in both health and disease, including cancer, immune signaling and stem cell biology.

"We've known that the human genome still has a number of tricks up its sleeve," said Eric Lander, founding director of the Broad Institute and co-senior author of the Nature paper. "But, it is astounding to realize that there is a huge class of RNA-based genes that we have almost entirely missed until now".

Standard "textbook" genes encode RNAs that are translated into proteins, and mammalian genomes harbor about 20,000 such protein-coding genes. Some genes, however, encode functional RNAs that are never translated into proteins. These include a handful of classical examples known for decades and some recently discovered classes of tiny RNAs, such as microRNAs.

By contrast, the newly discovered lincRNAs are thousands of bases long. Because only about ten examples of functional lincRNAs were known previously, they seemed more like genomic oddities than critical components. The new Nature study shows that there are actually thousands of such genes and that they have been conserved across mammalian evolution......... Posted by: Kelly      Read more         Source

January 30, 2009, 6:22 AM CT

Surprising lion stronghold in central Africa

Times are tough for wildlife living at the frontier between Uganda and the Democratic Republic of the Congo. Armies are reportedly encamped in a national park and wildlife preserve on the Congolese side, while displaced herders and their cattle have settled in an adjoining Ugandan park.

And yet, the profusion of prey in the region could potentially support more than 900 individuals of the emblematic African lion, as per new research but only if immediate conservation steps are taken.

"Those two protected areas that straddle the frontier could be the stronghold for lions in central Africa the largest population," says University of Wisconsin-Madison environmental studies professor Adrian Treves, the study's main author. "Therefore, (the population) is critically important, because the lion is now considered threatened throughout Africa".

He and fellow scientists from the Wildlife Conservation Society and the Panthera Foundation report their findings in the recent issue of the journal Oryx, which published online today (Jan. 29).

While the conflict raging in D.R. Congo makes conservation efforts in that country's Parque National Virungas (PNVi) nearly impossible right now, says Treves, action can be taken in Uganda's Queen Elizabeth National Park (QENP). In an attempt to protect their livestock, cattlemen there have reportedly poisoned and shot predators in large numbers, stirring fears that the king of beasts appears to be driven to extinction in Uganda......... Posted by: Kelly      Read more         Source