September 1, 2010, 7:11 AM CT

Free as a bird?

It may seem like birds have the freedom to fly wherever they like, but scientists at the University of Missouri have shown that what's on the ground has a great effect on where a bird flies. This information could be used by foresters and urban planners to improve bird habitats that would help maintain strong bird populations.

"Movement of individuals influences nearly every aspect of biology, from the existence of a single population to interactions within and among species," said Dylan Kesler, assistant professor in fisheries and wildlife at the University of Missouri's School of Natural Resources. "Movement determines where individual birds procreate. How they spread across the landscape affects who meets whom, which in turn dictates how genes are spread".

Kesler has observed that non-migrating resident birds tend to travel over forest "corridors," which are areas protected by trees and used by wildlife to travel. Birds choose to travel over forests because they can make an easier escape from predators as well as find food. Man-made features such as roads, as well as gaps forests from agriculture or rivers, can restrict birds to certain areas. When forests are removed, bird populations become isolated and disconnected, which can lead to inbreeding and weaker, more disease-prone birds......... Posted by: Kelly      Read more         Source

September 1, 2010, 7:08 AM CT

Effects of Sound on Marine Life

A combination of the biology of marine mammals, mechanical vibrations and acoustics has led to a breakthrough discovery allowing researchers to better understand the potential harmful effects of sound on marine mammals such as whales and dolphins.

An international team of scientists from San Diego State University, UC San Diego, and the Kolmården Zoo in Sweden has developed an approach that integrates advanced computing, X-ray Computerized axial tomography scanners, and modern computational methods that give a 3D simulated look inside the head of a Cuvier's beaked whale.

"Our numerical analysis software can be used to conduct basic research into the mechanism of sound production and hearing in these whales, simulate exposure at sound pressure levels that would be impossible on live animals, or assess various mitigation strategies," said Petr Krysl, a UC San Diego structural engineering professor who developed the computational methods for this research. "We think that our research can enable us to understand, and eventually reduce, the potential negative effects of high intensity sound on marine organisms."

The results of this research were recently published in a PLoS ONE article entitled, "A New Acoustic Portal into the Odontocete Ear and Vibrational Analysis of the Tympanoperiotic Complex" by Krysl, Ted W. Cranford, an adjunct professor of research in biology at San Diego State University; and Mats Amundin, a researcher at Sweden's Kolmården Zoo. Sponsors of the research include the office of the Chief of Naval Operations (CNO), Environmental Readiness Division......... Posted by: Kelly      Read more         Source

August 26, 2010, 11:16 PM CT

Ants use multiple antibiotics as weed killers

Research led by Dr Matt Hutchings and published recently in the journal BMC Biology shows that ants use the antibiotics to inhibit the growth of unwanted fungi and bacteria in their fungus cultures which they use to feed their larvae and queen.

These antibiotics are produced by actinomycete bacteria that live on the ants in a mutual symbiosis.

Eventhough these ants have been studied for more than 100 years this is the first demonstration that a single ant colony uses multiple antibiotics and is reminiscent of the use of multidrug treatment to treat infections in humans.

The work, which was funded by the UK Medical Research Council, has also identified a new antibiotic that could be used to treat fungal infections.

Fungiculture in the insect world is practiced by ants, termites, beetles and gall midges.

Dr Hutchings' research investigates the Acromyrmex octospinosus leaf cutter ant, endemic in South and Central America and the southern US. These ants form the largest and most complex animal societies on earth with colonies of up to several million individuals. The garden worker ants researched were collected from three colonies in Trinidad and Tobago.

Dr Hutchings said: "This was really a fun project which started with a PhD student, Joerg Barke, streaking leaf-cutting ants onto agar plates to isolate antibiotic producing bacteria. Joerg, with his colleagues Ryan Seipke and Sabine Gruschow, really pushed this project forwards and made these major discoveries. They really deserve most of the credit for this work"......... Posted by: Kelly      Read more         Source

August 26, 2010, 11:06 PM CT

Genome Comparison of Ants

By comparing two species of ants, Shelley Berger, PhD, the Daniel S. Och University Professor at the University of Pennsylvania, and his colleagues Danny Reinberg, PhD, New York University, and Juergen Liebig, PhD, Arizona State University, have established an important new avenue of research for epigenetics -- the study of how the expression or suppression of particular genes affects an organism's characteristics, development, and even behavior.

Ants, the new model system used in this study, organize themselves into caste-based societies in which most of the individuals are sterile females, limited to highly specialized roles such as workers and soldiers. Only one queen and the relatively small contingent of male ants are fertile and able to reproduce. Yet despite such extreme differences in behavior and physical form, all females within the colony appear to be genetically identical.

Berger, who directs Penn's Epigenetics program, and his colleagues think that epigenetic mechanisms - chemical modifications to DNA and its supporting proteins that affect gene expression - appears to be critical in establishing such broad variations in behavior and morphology that arise in individuals, despite having the same genome.

As per a research findings published in Science this week, Berger, her Penn colleagues, and a diverse international team of collaborators including ant biologists, geneticists, and biochemists from Arizona State, NYU, Howard Hughes Medical Institute, and the Chinese Academy of Sciences, showed how differences in gene expression between two ant species, the Florida carpenter ant (Camponotus floridanus) and Jerdon's jumping ant (Harpegnathos saltator), correlate with separate castes in each......... Posted by: Kelly      Read more         Source

August 25, 2010, 7:08 AM CT

Make Way for Ducklings

Parent birds know best when it comes to taking care of their babies. But, when food gets scarce and they are forced to fly longer distances to grab a bite, "egg sitting" time drops off. What impact does this have on their brood?

"I guess everybody, from a human health perspective, knows that what a mother does during pregnancy can have all sorts of effects on her babies," says Bill Hopkins, an associate professor in the Department of Fisheries and Wildlife Sciences at Virginia Tech. He is holding a duckling in his hand. It's one of a number of he and his team are studying. "We study how these little guys can be affected by the things that mom does".

A member of his research team, Sarah DuRant, examines an egg. "If you look really closely," she says, "you can see the embryo moving".

With the support of the National Science Foundation (NSF), ecologists Hopkins and DuRant are studying wood ducks to better understand the impact of mom's nesting behavior on her ducklings and their ability to survive.

"How much time a female spends on her nest is going to influence the temperature that the nest is at," notes DuRant. The scientists incubate eggs at different temperatures to simulate warmer and cooler nesting conditions. "What we're interested in are very, very subtle changes in temperature, maybe a degree Celsius at most," adds Hopkins......... Posted by: Kelly      Read more         Source

August 25, 2010, 7:06 AM CT

Glue That Holds Oyster

Oyster reefs are on the decline, with over-harvesting and pollution reducing some stocks as much as 98 percent over the last two centuries.

With a growing awareness of oysters' critical roles filtering water, preventing erosion, guarding coasts from storm damage, and providing habitat for other organisms, scientists have been investigating how oyster reefs form in order to better understand the organisms and offer potential guidance to oyster re-introduction projects.

At the same time, scientists have been studying marine animals' various adhesives, uncovering fundamental properties that could yield new innovations from replacements for medical sutures to surface coatings that keep waterborne craft from picking up marine hitchhikers.

Now, scientists from Purdue University and the University of South Carolina have shown that oysters produce a unique adhesive material for affixing themselves to each other, a cement that differs from the glues used by other marine organisms.

The scientists are presenting their findings at the 2010 Annual Meeting of the American Chemical Society in Boston, Mass., on Aug. 24, and will publish their results in the Sept. 15, 2010, issue of the Journal of the American Chemical Society. (The article is available online now.)......... Posted by: Kelly      Read more         Source

August 10, 2010, 6:33 AM CT

Fluorescence Shed New Light

A lot has changed about the way researchers study sexual selection and reproduction. Some of it has to do with new tools; some of it has to do with new attitudes. There is a lot more going on than just "sperm meets egg".

"It was simply thought of as "this army of sperm competing," so it functioned as a raffle; the more tickets you bought, the more sperm you transferred, the more likely you were to win out in that competition," explains Scott Pitnick, a professor of biology at Syracuse University. "Females were perceived as these passive vessels in which this competition played out--that females didn't play an active role. That's really not the case."

With help from the National Science Foundation (NSF), Pitnick studies reproduction and sexual selection in fruit flies.

"A sea change came in the mid-'90s in earnest when people started paying attention to the female side of things, and sperm-female interactions, and it turns out that's really where all the action is," he continues. "There has been a real male bias in this field, as in most fields of science. And now, in the sperm competition field, there are as a number of female as male [scientists], and it really has changed the focus considerably and in a very positive way".

For example, modern DNA technology that can confirm paternity opened scientists' eyes to the reality that monogamy is more the exception than the rule in most species......... Posted by: Kelly      Read more         Source

July 23, 2010, 6:50 AM CT

Ancient "stress hormone" in pre-historic fish

A University of British Columbia zoologist has discovered a new corticosteroid hormone in the sea lamprey, an eel-like fish and one of the earliest vertebrates dating back 500 million years. These findings have shed light on the evolution of steroid hormones and may help conservation and management efforts for lampreys.

"This new discovery has significant scientific implications and application for lamprey conservation," says principal investigator and main author David Close, an assistant professor in the UBC Department of Zoology and director of the Aboriginal Fisheries Research Unit at UBC's Fisheries Centre.

Close and his colleagues at Michigan State University identified a corticosteroid hormone - called 11-deoxycortisol - in the sea lamprey that plays dual roles in balancing ions and regulating stresses, similar to aldosterone and cortisol in humans. The findings are published online this week in the Proceedings of National Academy of Sciences Early Edition.

Native to the Pacific Coast of North America and Asia, Pacific lampreys are an important ceremonial and subsistence food for Aboriginal peoples in the Columbia River basin. They are born in freshwater, swim out to the ocean as adults and return to freshwater to reproduce in similar habitats to Pacific salmon and trout. Adult lampreys can grow to approximately 75 cm long and use their sucker-like mouth to attach to other fish while in the ocean......... Posted by: Kelly      Read more         Source

July 12, 2010, 7:17 AM CT

New virus may pose risk to wild salmon

Farmed fish are an increasingly important food source, with a global harvest now at 110 million tons and growing at more than 8 percent a year. But epidemics of infectious disease threaten this vital industry, including one of its most popular products: farmed Atlantic salmon. Perhaps even more worrisome: these infections can spread to wild fish coming in close proximity to marine pens and fish escaping from them.

Heart and skeletal muscle inflammation (HSMI), an often fatal disease, was first detected in salmon on a farm in Norway in 1999, and has now been reported in 417 fish farms in Norway as well as in the United Kingdom. The disease destroys heart and muscle tissue and kills up to 20 percent of infected fish. Eventhough studies have indicated an infectious basis, recent efforts to identify the pathogen causing the disease have been unsuccessful. Now, using cutting-edge molecular techniques, an international team led by W. Ian Lipkin, MD, the John Snow Professor of Epidemiology and director of the Center for Infection and Immunity at Columbia University's Mailman School of Public Health, has found evidence that the disease appears to be caused by a previously unknown virus. The newly identified virus is related but distinct from previously known reoviruses, which are double-stranded RNA viruses that infect a wide range of vertebrates......... Posted by: Kelly      Read more         Source

July 12, 2010, 7:10 AM CT

Mexican salamander and mysteries of stem cells

Dr Andrew Johnson is speaking today (12 July) at the UK National Stem Cell Network annual conference. He and his team from the University of Nottingham have been using a Mexican aquatic salamander called an axolotl to study the evolution and genetics of stem cells - research that supports the development of regenerative medicine to treat the consequences of disease and injury using stem cell therapies. This team has observed that there are extraordinary similarities in the development of axolotls and mammals that provide unique opportunities to study the properties of embryonic stem cells and germ cells. These findings are underpinned by a novel theory of evolution that unifies the diversity of mechanisms in animal developmental into a single conceptual framework.

Dr Johnson said "We've produced evidence that pluripotency the ability of an embryonic stem cell to become absolutely any kind of cell is actually very ancient in evolutionary terms. Even though received wisdom is that it evolved with mammals, our research suggests that it was there all along, just not in a number of of the species that people use in the lab. In fact, pluripotent cells probably exist in the embryos of the simple animals from which amphibians evolved.

"Axolotls, unlike a number of of the frogs, fish, flies and worms that are used in the lab, have pluripotent cells in their embryos that are the equivalent to those found in embryos from mammals, in that they can produce germ cells, in addition to somatic cells, a property known as ground-state pluripotency. And from a practical perspective, axolotl embryos will provide a very useful tool for understanding how to manipulate embryonic stem cells for modern regenerative medicine"......... Posted by: Kelly      Read more         Source

July 7, 2010, 7:06 AM CT

Deworming lambs

Deworming lambs can be minimized with rotational grazing and checking the animals' eye color, as per an Agricultural Research Service (ARS) study.

Animal scientist Joan Burke at the ARS Dale Bumpers Small Farms Research Center in Booneville, Ark., and his colleagues made this finding as part of a continuing collaboration with scientists, veterinarians, and extension agents from the Southern Consortium for Small Ruminant Parasite Control.

The consortium was formed in response to the threats posed by worms resistant to parasiticides. Unnecessary de-worming speeds development of resistant worms. Reducing the use of conventional parasiticides fits well into organic and grass-fed management systems and meets consumer preferences of minimizing chemical residues in meat.

The blood-sucking worm, Haemonchus contortus, can cause severe anemia in animals. It is called the barber pole worm for the spiraling of its white, egg-filled ovaries around blood-filled intestines. Worldwide, they cost farmers and ranchers millions of dollars in losses. Animals shed worm eggs with their manure, and the larvae that hatch can be eaten by other livestock.

Burke and his colleagues observed that gel capsules filled with copper oxide wire particles eliminated the need for conventional dewormers in all but one case. And lambs that also rotated pastures needed fewer dewormings with the copper oxide pills......... Posted by: Kelly      Read more         Source

July 7, 2010, 6:59 AM CT

Lone whales shout to overcome noise

noise increases; and just like humans, at a certain point, it appears to become too costly to continue to shout, as per marine and acoustic scientists.

"The impacts of increases in ocean noise from human activities are a concern for the conservation of marine animals like right whales," said Susan Parks, assistant professor of acoustics and research associate, Applied Research Laboratory, Penn State. "The ability to change vocalizations to compensate for environmental noise is critical for successful communication in an increasingly noisy ocean".

Right whales are large baleen whales that often approach close to shore. They may have been given the name because they were the right whales to hunt as they are rich in blubber, slow swimming and remain afloat after death. Consequently, whalers nearly hunted these whales to extinction. Currently right whales are monitored to determine the health and size of the population. The northern and southern right whales are on the endangered species list.

"Right whale upcalls are used extensively for passive acoustic monitoring in conservation efforts to protect this endangered species," said Parks.

Whales produce upcalls, sometimes called contact calls, when they are alone or in the process of joining with other whales. An upcall begins low and rises in pitch. It is the most frequent call produced by right whales......... Posted by: Kelly      Read more         Source

July 6, 2010, 7:16 AM CT

Salmon in hot water

Rearing juvenile salmon at the relatively high temperature of 16C causes skeletal deformities in the fish. Scientists writing in the open access journal BMC Physiology investigated both the magnitude and mechanisms of this effect, which occurs when salmon farmers use warmed water to increase fish growth rates.

Harald Takle worked with a team of scientists from NOFIMA (the Norwegian Institute of Food, Fisheries and Aquaculture Research), Norway, to carry out the studies. He said, "The data presented here indicate that both production of bone and cartilage were disrupted when promoting fast growth using elevated temperature. It is very likely that higher temperatures result in the increased rate of deformities observed in the 16C group".

The scientists reared 400 fish in 10C water and another 400 at 16C. The fish in the 16C water grew faster, but 28% were found to show some signs of skeletal deformity, in comparison to 8% of the fish reared in the cooler tank. Takle said, "Our results strongly indicate that temperature induced fast growth is severely affecting gene transcription in osteoblasts and chondrocyte bone cells, leading to a change in the tissue structure and composition".

In a second related study, fish with vertebral deformities were studied in detail. Takle said, "The deformity process involves molecular regulation and cellular changes similar to those found in mammalian intervertebral disc degeneration"......... Posted by: Kelly      Read more         Source

July 6, 2010, 7:13 AM CT

Digital embryo gains wings

The researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Gera number of, who 'fathered' the Digital Embryo have now given it wings, creating the Fly Digital Embryo. In work published recently in Nature Methods, they were able to capture fruit fly development on film, and were the first to clearly record how a zebrafish's eyes and midbrain are formed. The improved technique will also help to shed light on processes and organisms, which have so far been under-studied because they could not be followed under a microscope.

"Non-transparent samples like the fruit fly embryo scatter light, so the microscope picks up a mixture of in-focus and out-of-focus signal good and bad information, if you like," says Ernst Stelzer, whose group carried out the project at EMBL. "Our new technique enables us to discriminate between that good and bad information, so it allows us to record organisms which have so far been poorly studied, because of their unfortunate optical properties".

Philipp Keller, who co-led and conducted the work, and Ernst Stelzer overcame the difficulties caused by thick, opaque samples, by shining patterns of light on them, instead of the usual continuous light sheet. This generates an image with alternating light and dark stripes, unless the light bounces off the sample and changes direction, in which case this stripy pattern will be blurred. By taking multiple images of different phases of the light pattern, and combining them, a computer can filter out the effects of scattered light and generate an accurate image of the sample, thus enabling researchers to record images that were previously unobtainable......... Posted by: Kelly      Read more         Source

June 24, 2010, 11:15 PM CT

System that controls sleep

In a novel mathematical model that reproduces sleep patterns for multiple species, an international team of scientists has demonstrated that the neural circuitry that controls the sleep/wake cycle in humans may also control the sleep patterns of 17 different mammalian species. These findings, reported by scientists from Brigham and Women's Hospital (BWH), the University of Sydney, and the Center for Integrated Research and Understanding of Sleep (Camperdown, Australia), suggest that fundamental physiological mechanisms are at work across diverse species, even though sleep patterns vary drastically. This research published June 24th in the open-access journal PLoS Computational Biology.

"These findings show that eventhough mammalian sleep is remarkably diverse in expression, from dolphins who sleep with one brain half at a time to rodents who have a number of short naps, it is very likely universal in origin, which suggests that this simple system is both highly flexible and evolutionarily conserved," said Andrew Phillips, main author of the paper and researcher in the Division of Sleep Medicine at BWH.

Over the past decade, scientists have reported findings correlation to the structures in the brain that are critical to sleep regulation, but these findings have been limited to a small number of species. Until now, it was unclear to what extent these physiological mechanisms are universal across all mammals, particularly given such large interspecies differences in sleep patterns......... Posted by: Kelly      Read more         Source

June 24, 2010, 10:36 PM CT

Even brooding female birds are sensitive to visual stimulation

In a breeding experiment with Houbara bustards - a North African bird species with a very distinctive courtship behaviour, researchers have concluded that visual stimulation from attractive males of the same species positively affects brooding females, improving offspring growth. Females that observed highly displaying male birds in the experiment were more fertile and had a greater breeding success due to an increased allocation of testosterone into their eggs, leading to an increase in the growth rate in chicks. The results showed that using artificial insemination without appropriate stimulation of breeding females probably has negative impacts on their breeding performance and can therefore even affect the survival of a species, as per Adeline Loyau and Frederic Lacroix in the online edition of Proceedings of the Royal Society B

For the experiment, Loyau of the Helmholtz Center for Environmental Research (UFZ) and the French CNRS station for experimental ecology and her colleague Lacroix (ECWP) confronted 90 brooding Houbara bustard females (Chlamydotis undulata undulata) with various individuals of the same species. In the Emirates Center for Wildlife Propagation (ECWP) in Moroccan Missour, 30 female birds were visually confronted with either highly displaying male birds, poorly displaying male birds, or females. During the experiment the female birds under investigation were artificially inseminated and kept isolated in aviaries five meters apart from birds of the same species in other aviaries. That way the researchers were able to exclude any other factors from playing a role in the experiment other than that of visual stimulation. "To my knowledge our study is the first example in species conservation of a successful manipulation of maternal allocation of resources through sensory stimulation ", explains behavioural biologist Adeline Loyau from the UFZ, "Our results show that it is possible to control maternal allocation of resources independent of the quality of male genes." Male display courtship constitutes an effective signal thereby providing conservationists with a simple and inexpensive means. The results could therefore be very significant for the improvement of captive breeding programs of other threatened bird species......... Posted by: Kelly      Read more         Source

June 24, 2010, 10:15 PM CT

3D Models of Whole Mouse Organs

Yale University engineers have for the first time created 3D models of whole intact mouse organs, a feat they accomplished using fluorescence microscopy. The team reports its findings in the May/recent issue of the Journal of Biomedical Optics, as per a research findings published online this week.

Combining an imaging technique called multiphoton microscopy with "optical clearing," which uses a solution that renders tissue transparent, the scientists were able to scan mouse organs and create high-resolution images of the brain, small intestine, large intestine, kidney, lung and testicles. They then created 3D models of the complete organs-a feat that, until now, was only possible by slicing the organs into thin sections or destroying them in the process, a disadvantage if more information about the sample is needed after the fact.

With traditional microscopy, scientists are only able to image tissues up to depths on the order of 300 microns, or about three times the thickness of a human hair. In that process, tissue samples are cut into thin slices, stained with dyes to highlight different structures and cell types, individually imaged, then stacked back together to create 3D models. The Yale team, by contrast, was able to avoid slicing or staining the organs by relying on natural fluorescence generated from the tissue itself......... Posted by: Kelly      Read more         Source

June 14, 2010, 10:08 PM CT

Sequencing the salmon genome

The economically important, environmentally sensitive Atlantic salmon species is one step closer to having its genome fully sequenced, thanks to an international collaboration involving researchers, funding agencies and industry from Canada, Chile and Norway.

Genome BC partnered with the Chilean Economic Development Agency, InnovaChile, Norwegian Research Council, Norwegian Fishery and Aquaculture Industry Research Fund to form the International Cooperation to Sequence the Atlantic Salmon Genome (the Cooperation).

Together they are well underway on a multi-million dollar, multi-phased project that will produce a genome sequence that identifies and maps all of the genes in the Atlantic salmon genome and can act as a reference/guide sequence for the genomes of other salmonids (e.g. Pacific salmon, rainbow trout and more distantly related fish such as smelt and pike.).

Phase one of the project was awarded to Beckman Coulter Genomics to produce a 4X coverage genome using paired-end, plasmid, fosmid and BAC Sanger sequences. It is expected that this phase will be complete in January, 2011.

The Cooperation is gearing up for phase two which will result in a high definition and well-annotated genome using primarily next generation sequencing technologies. The Cooperation is seeking interested parties (publically or privately funded genome sequencing centres, or public/private partnerships) to undertake phase two......... Posted by: Kelly      Read more         Source

June 9, 2010, 11:25 PM CT

Impact of fishing on remote coral reefs

Coral reefs - kaleidoscopes of pink anemones and silver sharks - are the planet's most colorful ecosystems and among its most endangered, say marine scientists.

As global warming raises ocean temperatures, a number of corals blanch and die, a phenomenon called "coral bleaching." And pumping large amounts of carbon dioxide into the atmosphere could make the ocean more acidic, further decimating corals and the fish that depend on them for food and shelter.

Millions of people inhabit coral reefs around the world, putting additional pressure on reef menageries. Establishing sustainable fisheries, even at remote islands and atolls, could significantly slow the decline of a number of reefs, say marine ecologists.

"We know that fishing can dramatically change the composition of a reef ecosystem," said Fiorenza Micheli, a professor of biology at Stanford University's Hopkins Marine Station. "By confronting overfishing immediately, we may increase the resilience of coral reefs to global warming and other threats".

To gain new insights on the ecology of reef fishing, Micheli and a team of Stanford scientists are taking advantage of an ongoing "natural experiment" at two isolated Pacific atolls - Palmyra and Tabuaeran (or Fanning Island) - located about 1,000 miles south of Hawaii. The project is funded by Stanford's Woods Institute for the Environment......... Posted by: Kelly      Read more         Source

May 6, 2010, 6:44 AM CT

Mammal Diversity Patterns

Travel from the tropics to the poles, and you'll notice that the diversity of mammals declines with distance from the equator. Move from lowland to mountains, and you'll see diversity increase as the landscape becomes more varied. Ecologists have proposed various explanations for these well-known "biodiversity gradients," invoking ecological, evolutionary and historical processes.

New findings by University of Michigan scientists John A. Finarelli and Catherine Badgley suggest that the elevational patterns of diversity we see today have appeared, disappeared and reappeared over Earth's history and that these patterns arise from interactions between climate change and mountain building.

The results, published online in the journal Proceedings of the Royal Society B, also have implications for conservation efforts in the face of modern-day global warming, said Finarelli, a visiting assistant professor in the Department of Geological Sciences.

In their study, focused on the Miocene Epoch, which began around 23 million years ago and ended about 5 million years ago, Finarelli and Badgley reviewed diversity for more than 400 rodent species from adjacent regions that differed in geologic history and topography. The geologically "active region," which extends from the Front Range of the Rocky Mountains to the Pacific coast, has experienced several episodes of mountain-building and volcanic activity, and as a result has a topographically complex landscape. In contrast, the relatively flat Great Plains, has been more stable geologically......... Posted by: Kelly      Read more         Source

April 26, 2010, 7:27 PM CT

New monitor lizard discovered

A newly discovered species of monitor lizard, a close relative of the Komodo dragon, was published in the journal Zootaxa this week by a professor at UC Santa Barbara and a researcher from Finland.

Sam Sweet, a professor in the department of Ecology, Evolution and Marine Biology at UCSB, and Valter Weijola, a graduate student at Abo Akademi University in Turku, Finland, are the first to describe the distinctive lizard, which lives in the Moluccan islands of east Indonesia. Sweet is an authority on monitor lizard biology.

The scientific name of this lizard is Varanus obor; its popular names are Torch monitor and Sago monitor. It's called Torch monitor because of its bright orange head with a glossy black body. Obor means torch in Indonesian. It is a close relative of the fruit-eating monitor lizard recently reported from the Philippines. The Torch monitor can grow to nearly four feet in length, and thrives on a diet of small animals and carrion.

The Torch monitor exists only on the small island of Sanana in the western Moluccan islands. A unique aspect of this geographical region is the lack of mammalian predators, which may have given reptiles the space to evolve as the top terrestrial predators and scavengers. Several million years ago, this island was situated near New Guinea, and it is possible that the lizard lives on as a relic from that period. It is the only black monitor in its lineage, and the only monitor species anywhere that has evolved red pigmentation......... Posted by: Kelly      Read more         Source

March 24, 2010, 10:27 AM CT

Petri Sheep

In the winter of 2003, a large herd of bison in an Idaho feedlot was cut in half when a disease outbreak swept through, killing 825 animals.

Two years ago, 19 cattle, most owned by FFA students, died after being shown in Washington's Puyallup State Fair.

In both instances, Washington State University scientists determined the animals died of cancerous catarrhal fever because they had been kept near flocks of sheep, which routinely carry a disease called ovine herpes virus 2. Scientists have known of the disease for decades, but have repeatedly been frustrated in their attempts to grow it in a lab-a major step in developing a vaccine.

So they use the next best thing to a Petri dish: sheep.

USDA and WSU researchers, writing in an upcoming issue of the journal Veterinary Microbiology, say they have propagated the virus in sheep and for the first time identified specific cells where it can replicate. Their discovery opens the door for growing these cells and the virus in a laboratory setting, where they can then begin developing vaccines.

Naomi Taus, main author and veterinary medical officer for the Pullman unit of the USDA's Agricultural Research Service, says she and her colleagues collected secretions from sheep-snot, actually-and aerosolized it to expose other sheep. They then took tissue samples from the sheep and searched for infections by looking for fluorescent markers designed to bind with proteins linked to the virus and certain cell types......... Posted by: Kelly      Read more         Source

March 19, 2010, 10:50 AM CT

Mexican Cave Scorpions

Blind scorpions that live in the stygian depths of caves are throwing light on a long-held assumption, showing that specialized adaptations aren't always an evolutionary dead-end. Looking at the phylogenetic relationships among species of the scorpion family Typhlochactidae, endemic to Mexico, Associate Curator Lorenzo Prendini and his colleagues observed that species currently living closer to the surface (under stones and in leaf litter) evolved independently on more than one occasion from specialized deep-cave ancestors adapted to life further below the surface (in caves). This finding puts a dent in both Cope's Law of the unspecialized, which assumes that novel evolutionary traits tend to originate from a generalized member of an ancestral taxon, and Dollo's Law of evolutionary irreversibility, which theorizes that specialized evolutionary traits are unlikely to reverse.

Scorpions are predatory, venomous, nocturnal arachnids correlation to spiders, mites, and other arthropods. About 2,000 species are distributed throughout the world, but only 23 species found in ten different families are adapted to a permanent life in caves. One of these families is the Typhlochactidae, comprising four genera and nine species.

"Scorpions have been around for 450 million years, and their biology is obviously flexible," says Prendini. "This unique group of eyeless Mexican scorpions may have started re-colonizing niches closer to the surface from the deep caves of Mexico after their surface-living ancestors were wiped out by the nearby Chicxuluxb impact along with non-avian dinosaurs, ammonites, and other species"......... Posted by: Kelly      Read more         Source

March 19, 2010, 10:48 AM CT

Dogs likely originated in the Middle East

Dogs likely originated in the Middle East, not Asia or Europe, as per a new genetic analysis by an international team of researchers led by UCLA biologists. The research, funded by the National Science Foundation and the Searle Scholars Program, appears March 17 in the advance online edition of the journal Nature.

"Dogs seem to share more genetic similarity with Middle Eastern gray wolves than with any other wolf population worldwide," said Robert Wayne, UCLA professor of ecology and evolutionary biology and senior author of the Nature paper. "Genome-wide analysis now directly suggests a Middle East origin for modern dogs. We have observed that a dominant proportion of modern dogs' ancestry derives from Middle Eastern wolves, and this finding is consistent with the hypothesis that dogs originated in the Middle East.

"This is the same area where domestic cats and a number of of our livestock originated and where agriculture first developed," Wayne noted.

Prior genetic research suggested an East Asian origin for dogs, "which was unexpected," Wayne said, "because there was never a hint in the archaeological record that dogs evolved there".

"We were able to study a broader sampling of wolves globally than has ever been done before, including Middle Eastern wolves," said the paper's main author, Bridgett vonHoldt, a UCLA graduate student of ecology and evolutionary biology in Wayne's laboratory who studies the genetics of dog domestication. "In our analysis of the entire genome, we observed that dogs share more unique markers with Middle Eastern wolves than with East Asian wolves. We used a genome-wide approach, which avoids the bias of single genome region"......... Posted by: Kelly      Read more         Source

March 17, 2010, 8:17 PM CT

Spider silk reveals a paradox

Since its development in China thousands of years ago, silk from silkworms, spiders and other insects has been used for high-end, luxury fabrics as well as for parachutes and medical sutures. Now, National Science Foundation-supported scientists are untangling some of its most closely guarded secrets, and explaining why silk is so super strong.

Scientists at the Massachusetts Institute of Technology's Center for Materials Science and Engineering say the key to silk's pound-for-pound toughness, which exceeds that of steel, is its beta-sheet crystals, the nano-sized cross-linking domains that hold the material together.

Markus Buehler, the Esther and Harold E. Edgerton Associate Professor in MIT's department of civil and environmental engineering, and his team recently used computer models to simulate exactly how the components of beta sheet crystals move and interact with each other. They observed that an unusual arrangement of hydrogen bonds--the "glue" that stabilizes the beta-sheet crystals--play an important role in defining the strength of silk.

They observed that hydrogen bonds, which are among the weakest types of chemical bonds, gain strength when confined to spaces on the order of a few nanometers in size. Once in close proximity, the hydrogen bonds work together and become extremely strong. Moreover, if a hydrogen bond breaks, there are still a number of hydrogen bonds left that can contribute to the material's overall strength, due to their ability to "self-heal" the beta-sheet crystals......... Posted by: Kelly      Read more         Source

March 12, 2010, 7:41 AM CT

Why female moths are big and beautiful?

In most animal species, males and females show obvious differences in body size. But how can this be, given that both sexes share the same genes governing their growth? University of Arizona entomologists studied this conundrum in moths and found clues that had been overlooked by prior efforts to explain this mystery of nature.

Take a look around in the animal world and you will find that, in most organisms, individuals of one sex are larger than the other of the species.

Even though evolutionary biologists have long recognized this discrepancy, called sexual dimorphism, they have struggled for decades to solve a major paradox: How can males and females of one species be of different sizes, given that they share the same genetic blueprints dictating their development and growth?

Scientists from the University of Arizona have discovered that the key to unraveling this mystery lies in the early developmental stages during which the sexes begin to grow apart and that females can respond to selection on size almost twice as fast as can males.

Their findings are published online before print in Proceedings of the Royal Society of London, Series B

"In mammals, the males tend to be larger because there is an advantage in being bigger and stronger when it comes to fighting over who gets the female," explained Craig Stillwell, main author of the study and a UA Center for Insect Science postdoctoral fellow in the lab of Goggy Davidowitz, an assistant professor of entomology at the UA......... Posted by: Kelly      Read more         Source

March 11, 2010, 11:06 PM CT

Yellow fever strikes monkey populations

A group of Argentine scientists, including health experts from the Wildlife Conservation Society, have announced that yellow fever is the culprit in a 2007-2008 die-off of howler monkeys in northeastern Argentina, a finding that underscores the importance of paying attention to the health of wildlife and how the health of people and wild nature are so closely linked.

The paperappearing in a recent edition of the American Journal of Primatologyfocuses on yellow fever outbreaks that were documented in several howler monkey populations of Misiones Province, Argentina. The epidemics, which caused the death of dozens of rare howler monkeys, signaled the need for a human vaccination program in the region to save lives.

The authors of the study include: Ingrid Holzmann and Mario S. Di Bitetti of the Argentine Council for Science and Technology (CONICET); Ilaria Agostini of the Universidad de Roma and CNR; Juan Ignacio Areta of Grupo FALCO; and Hebe Ferreyra and Pablo Beldomenico of the Wildlife Conservation Society.

"The outbreak has tragic conservation implications for the endangered brown howler monkey, one of the two species affected, which is highly threatened primarily by habitat destruction, hunting, and now disease," said Dr. Pablo Beldomenico. "The study also points out the importance of wildlife as a critically important indicator of health and disease processes which can help protect people too."........ Posted by: Kelly      Read more         Source

March 10, 2010, 8:20 AM CT

Hidden habits and movements of insect pests

For a high-resolution image of the Asota caricae moth referenced in the article, visit http://bit.ly/aB4PEb. The moth has a two-inch wingspan and a 2,500 mile distribution. Image is courtesy of Lauren Helgen, Smithsonian Institution. For a copy of the research paper, contact Jeff Falk at jfalk@umn.edu.

Contacts: Peggy Rinard, College of Biological Sciences, rinar001@umn.edu, (612) 624-0774.

Jeff Falk, University News Service, jfalk@umn.edu, (612) 626-1720.

MINNEAPOLIS / ST. PAUL (03/09/2010) -University of Minnesota researcher George Weiblen and his colleagues have found a faster way to study the spread and diet of insect pests.

Using a technique called DNA barcoding, which involves the identification of species from a short DNA sequence, Weiblen and an international team of scientists studied populations of numerous moth and butterfly species across Papua New Guinea. DNA barcodes showed that migratory patterns and caterpillar diets are very dynamic. In one case, a tiny moth that is distributed from Taiwan to Australia, has recently crossed thousands of miles of Pacific Ocean.

The research, "Population genetics of ecological communities with DNA barcodes: An example from New Guinea Lepidoptera," was reported in the Early Online edition of Proceedings of the National Academy of Sciences on March 1......... Posted by: Kelly      Read more         Source

March 9, 2010, 8:30 AM CT

Musk Ox Population Decline Due to Climate

team of researchers has discovered that the drastic decline in Arctic musk ox populations that began roughly 12,000 years ago was due to a warming climate rather than to human hunting. "This is the first study to use ancient musk ox DNA collected from across the animal's former geographic range to test for human impacts on musk ox populations," said Beth Shapiro, the Shaffer Career Development assistant professor of biology at Penn State University and one of the team's leaders. "We observed that, eventhough human and musk ox populations overlapped in a number of regions across the globe, humans probably were not responsible for the decline and eventual extinction of musk oxen across much of their former range." The team's findings would be reported in the 8 March 2010 issue of the journal Proceedings of the National Academy of Sciences.

Musk oxen once were plentiful across the entire Northern Hemisphere, but they now exist almost solely in Greenland and number only about 80,000 to 125,000. As per the researchers, musk oxen are not the only animals to suffer during the late Pleistocene Epoch. "The late Pleistocene was marked by rapid environmental change as well as the beginning of the spread of humans across the Northern Hemisphere," said Shapiro. "During that time several animals became extinct, including mammoths and woolly rhinoceroses, while others, including horses, caribou, and bison, survived into the present. The reasons for these drastically different survival patterns have been debated widely, with some researchers claiming that the extinctions were due largely to human hunting. Musk oxen provide a unique opportunity to study this question because they suffered from a decline in their population that coincided with the Pleistocene extinctions, yet they still exist today, which allows us to compare the genetic diversity of today's individuals with those individuals that lived up to 60,000 years ago"......... Posted by: Kelly      Read more         Source

March 8, 2010, 9:09 AM CT

Snake venom charms science world

The King Cobra continues to weave its charm with scientists identifying a protein in its venom with the potential for new drug discovery and to advance understanding of disease mechanisms.

The novel protein named haditoxin has been described in the prestigious Journal of Biological Chemistry (March 12, 2010).

The editorial board of the journal has selected this work as the "Paper of the Week" recognising it as being in the top one per cent of their published articles in terms of significance and overall importance.

Haditoxin was discovered in Professor Manjunatha Kini's laboratory at the National University of Singapore. Co-author of the paper Dr S. Niru Nirthanan, now at Griffith University on the Gold Coast, has characterised the pharmacological actions of haditoxin.

Dr Nirthanan said that haditoxin was structurally unique and therefore expected to have unique pharmacological properties.

"This toxin is like a conjoined twin. It is a relatively large complex made up of two identical protein molecules known as three-finger toxins associated withgether."

"We know that the family of three-finger toxins display diverse biological actions on the human nervous system, cardiovascular system and blood clotting. Some have directly led to the development of compounds with potent analgesic and blood pressure reducing properties so it is likely that haditoxin in its 'conjoined twin' state or as individual components will offer us more novel insights," he said......... Posted by: Kelly      Read more         Source

February 25, 2010, 2:52 AM CT

Tree-dwelling mammals climb to the heights of longevity

The squirrels littering your lawn with acorns as they bound overhead will live to plague your yard longer than the ones that aerate it with their burrows, as per a University of Illinois study.

Researchers know from prior studies that flying birds and bats live longer than earthbound animals of the same size. Milena Shattuck and Scott Williams, doctoral candidates in anthropology, decided to take a closer look at the relationship between habitat and lifespan in mammals, comparing terrestrial and treetop life. They published their findings in the Proceedings of the National Academy of Sciences.

The two hypothesized that, like flight, treetop or arboreal dwelling reduces a species' extrinsic mortality - death from predation, disease and environmental hazards; that is, causes other than age.

"One of the predictions of the evolutionary theory of aging is that if you can reduce sources of extrinsic mortality, you'll end up exposing some of the late-acting mutations to natural selection, and therefore evolve longer lifespans," Williams said.

Williams and Shattuck observed that for arboreality, the theory holds. Mammals who spend the majority of their time up a tree enjoy longevity over those who scurry along the ground. The pattern holds consistent both on the large scale among all mammals, and also in specific classes the pair studied, such as tree squirrels versus ground squirrels......... Posted by: Kelly      Read more         Source

February 11, 2010, 8:17 AM CT

Big Cats in Serious Trouble Around the World

As a number of Asian countries prepare to celebrate Year of the Tiger beginning February 14, World Wildlife Fund (WWF) reports that tigers are in crisis around the world, including here in the United States, where more tigers are kept in captivity than are alive in the wild throughout Asia. As few as 3,200 tigers exist in the wild in Asia where they are threatened by poaching, habitat loss, illegal trafficking and the conversion of forests for infrastructure and plantations.

WWF is releasing a new interactive map of the world's top 10 tiger trouble spots and the main threats against tigers. WWF is also launching a campaign: Tx2: Double or Nothing to support tiger range states in their goal of doubling wild tiger numbers by the next Year of the Tiger in 2022.

The issues highlighted in the trouble spots map (www.worldwildlife.org/troublespots) include:

• Pulp, paper, palm oil and rubber companies are devastating the forests of Indonesia and Malaysia, home to two endangered tiger sub-species;
• Hundreds of new or proposed dams and roads in the Mekong region will fragment tiger habitat;
• Illegal trafficking in tiger bones, skins and meat feeds a continued demand in East and Southeast Asia;
• More tigers are kept in captivity in the U.S. than are left in the wild -- and there are few regulations to keep these tigers from ending up on the black market. The largest numbers of captive tigers are in Texas (an estimated 3,000+), but they are also kept in other states;
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Posted by: Kelly      Read more         Source