December 22, 2008, 5:31 AM CT

Snail and human have the same gene function

Biologists have tracked down genes that control the handedness of snail shells, and they turn out to be similar to the genes used by humans to set up the left and right sides of the body.

The finding, reported online in advance of publication in Nature by University of California, Berkeley, researchers, indicates that the same genes have been responsible for establishing the left-right asymmetry of animals for 500-650 million years, originating in the last common ancestor of all animals with bilateral body organization, creatures that include everything from worms to humans.

"Prior studies indicated that the methods for breaking left-right symmetry in animals seem to differ widely, so there was nothing suggesting that the common ancestor of humans, snails and other bilateral organisms had a common strategy for left-right asymmetry," said Nipam H. Patel, UC Berkeley professor of integrative biology and of molecular and cell biology, and an investigator of the Howard Hughes Medical Institute.

"Indeed, researchers thought that one of the genes that is critical for setting up left-right asymmetry in vertebrates was only present in vertebrates and related groups and not in any other animals," said UC Berkeley post-doctoral fellow Cristina Grande. "But we observed that gene in snails, which has a lot of evolutionary implications. This cellular pathway was present already in the ancestors of most animals"......... Posted by: Kelly      Read more         Source

December 18, 2008, 10:30 PM CT

Massive Jellyfish Swarms Released

Massive swarms of stinging jellyfish and jellyfish-like animals are transforming a number of world-class fisheries and tourist destinations into veritable jellytoriums that are intermittently jammed with pulsating, gelatinous creatures. Areas that are currently especially hard-hit by these squishy animals include Hawaii, the Gulf of Mexico, the east coast of the U.S., the Bering Sea, the Mediterranean Sea, Australia, the Black Sea and other European seas, the Sea of Japan, the North Sea and Namibia.

Massive jellyfish swarms--some of which cover hundreds of square miles--have caused injuries and even occasional deaths to water enthusiasts, and have caused serious damage to fisheries, fish farms, marine mines, desalination plants, ships and nuclear power plants. Since the 1980s, jellyfish swarms have cost the world's fishing and tourism industries alone hundreds of millions of dollars and perhaps even billions of dollars.

From large swarms of potentially deadly, peanut-sized jellyfish in Australia to swarms of hundreds of millions of refrigerator-sized jellyfish in the Sea of Japan, suspicion is growing that population explosions of jellyfish are being generated by human activities. Human activities that have been suggested by media reports and researchers as possible causes of some jellyfish swarms include pollution, climate change, introductions of non-native species, overfishing and the presence of artificial structures, such as oil and gas rigs. But which of these human activities, if any of them, are really to blame?........ Posted by: Kelly      Read more         Source

December 18, 2008, 10:22 PM CT

Polygamy, paternal care in birds linked to dinosaur ancestors

Sure, they're polygamous, but male emus and several other ground-dwelling birds also are devoted dads, serving as the sole incubators and caregivers to oversized broods from multiple mothers. It is rare behavior, but research described in the Dec. 19 Science observed that it runs in this avian family, all the way back to its dinosaur ancestors.

Researchers had long wondered about the origins of polygamy and paternal care patterns among modern-day Paleognathes -- an ancient avian lineage that branched off soon after birds evolved from dinosaurs and includes ostriches, emus and tinamous. No such reproductive behavior exists among the vast majority of other vertebrates. Males contribute to parental care in less than 5 percent of mammal and non-avian reptile species, and while more than 90 percent of bird species co-parent to some degree, it is only among the Paleognathes that both polygamy and paternal care rule.

Now, in a groundbreaking paper ("Avian Paternal Care Had Dinosaur Origin"), paleobiologist Gregory M. Erickson of The Florida State University and scientists from three other institutions connect the evolutionary dots linking the polygamous, paternal reproductive patterns of extant (living) birds to the behavior of their extinct dinosaur kin.

"In those cases where adult dinosaurs have been found on top of nests, we observed that the volume or mass of the egg clutch (total number of eggs in the nest) is very large relative to the size of the nesting animals," Erickson said. "This suggests multiple females contributed the eggs and the male guarded them. Notably, the ratio of egg volumes to the nesting animal's size is consistent with those in living birds where the male is the sole or primary nest attendant"......... Posted by: Kelly      Read more         Source

December 18, 2008, 10:05 PM CT

Male Dinosaurs: May Have Been Babysitters

Those ferocious Hollywood meat-eating dinosaurs you're used to seeing in the movies very possibly had a much softer side: the males might even have been sort of prehistoric babysitters, as per a far-flung study conducted by a Texas A&M University researcher.

Jason Moore, a post-doctoral researcher in the Department of Geology and Geophysics, and team members from Montana State University, Florida State University and the American Museum of Natural History in New York discovered that some types of male dinosaurs probably cared for and watched over eggs in much the same way that females of other species do. Their work appears in the current issue of Science magazine.

Moore and the research team examined six nests of well-preserved dinosaur eggs, with each nest containing from 22 to 30 eggs found in Montana and Mongolia. Most of the eggs were about 75 million years old.

Numerous clues - including the size of the eggs and the internal structure of the adult bones found sitting on the eggs - indicate that males, not females, likely watched over the eggs and served in a nanny-like function as the eggs slowly developed.

"The bones we found closest to the eggs don't display characteristics of female dinosaurs," Moore says of the findings.

"Modern birds descended from dinosaurs, so we can use birds as modern representatives of dinosaurs. We have looked at some other modern-day animals for similarities as well, including crocodiles, turtles, snakes and others, and asked the question in each case, 'Which of the parents were taking care of the eggs?' Comparing these modern animals to dinosaurs, the evidence all points to the males as the ones who likely cared for the eggs"......... Posted by: Kelly      Read more         Source

December 16, 2008, 9:24 PM CT

Treasure trove of 1,000 newly discovered species

A rat thought to beextinct for 11 million years, a spider with a foot-long legspan, and a hot pink cyanide-producing "dragon millipede" are among the thousand newly discovered species in the largely unexplored Mekong Delta region.

The region, including parts of Vietnam and five other countries, is home to 1,068 species found between 1997 and 2007, as per a World Wildlife Fund report released this week.

Some of the creatures were not lurking in fertile floodplains or tropical foliage.

A scientist visiting an outdoor restaurant was startled to see a Laotian rock rat among the nearby wildlife. The hairy, nocturnal, thick-tailed rat, which resembles a squirrel, had been thought for centuries to be extinct.

"There is a certain amount of shock because our researchers will sometimes see something that doesn't fit anything they know," said Dekila Chungyalpa, Director of the Fund's Mekong Program. "They run through a catalogue of wildlife in their brain, asking themselves, 'Have I seen this?'".

Perhaps a more startling discovery than the rat was a bright green pit viper researchers spotted slithering through the rafters of a restaurant in Khao Yai National Park in Thailand.

Read more........ Posted by: Kelly      Read more

December 15, 2008, 10:24 PM CT

Baby Koala Debuts At The LA Zoo

The Los Angeles Zoo and Botanical Gardens will unveil the newest member of the Zoo's koala family on Friday, December 12, 2008 at 9:30 a.m. Born on April 3, 2008, the newborn koala spent six months developing in the mother's pouch.

Baby koalas are usually referred to as joeys. When a koala is born, it is just three-fourths of an inch long. After birth they climb into the mother's pouch and stay there for six months. For the following six months, they are weaned from milk to eucalyptus as they stick their heads out of the pouch to eat partially digested leaves. After a year, they leave the pouch for good.

Eventhough they are often referred to as a "koala bear," koalas belong to the marsupial family. Marsupials are mammals whose females typically rear their young in a pouch through early infancy. Other members of the marsupial family are kangaroos, wallabies, wallaroos, wombats and opossums.

Native to Australia, koalas have a very low metabolic rate requiring them to conserve energy and to sleep between 18 and 20 hours a day. They spend about three of their five active hours eating a diet that consists entirely of eucalyptus leaves. Koalas consume 2 ½ pounds of leaves per day and rarely drink water due to the moisture found in eucalyptus leaves......... Posted by: Kelly      Read more         Source

December 15, 2008, 9:24 PM CT

Diverse landscapes are better

Diversity is valuable socially, economically and now environmentally.

Research by Michigan State University researchers has observed that growing more corn to produce ethanol creating less diverse landscapes reduces the ability of beneficial insects to control pests, a loss valued at about $58 million per year in the four states studied (Michigan, Iowa, Minnesota and Wisconsin).

"Corn is a less favorable habitat for a number of ladybird beetles (ladybugs) and other beneficial insects that feed on pests such as the soybean aphid," said Doug Landis, MSU professor of entomology. "As we plant more corn, we reduce the ability of that landscape to supply beneficial predators to control pests in soybeans and other crops. This results in increased pesticide use and yield losses. This research estimates the value of this biological pest control service in soybeans (in the four states) to be about $240 million each year".

The research was reported in the current issue of the Proceedings of the National Academy of Sciences

From 2006 to 2007, corn acreage increased by 19 percent in the United States, reducing landscape diversity in a number of areas, as per the scientists.

"Over-reliance on any one crop is likely to reduce the value of natural control of pest insects by beneficial insects," said Scott Swinton, MSU professor of agricultural, food and resource economics and paper co-author. "If we look at farmers who grow only corn and soybeans, increasing corn acreage and reducing soybean acreage will probably mean higher costs for soybean pest control. Beneficial insects help control pests so growers have lower pest control costs"......... Posted by: Kelly      Read more         Source

December 15, 2008, 9:06 PM CT

CO2 emissions will cause physiological impairment to jumbo squid

The elevated carbon dioxide levels expected to be found in the world's oceans by 2100 will likely lead to physiological impairments of jumbo (or Humboldt) squid, as per research by two University of Rhode Island scientists.

The results of a study by Brad Seibel, URI assistant professor of biological sciences, and Rui Rosa, a former URI post-doctoral student now on the faculty at the University of Lisbon, Portugal, is reported in this week's issue of the Proceedings of the National Academy of Sciences

The scientists subjected the squids (Dosidicus gigas) to elevated concentrations of CO₂ equivalent to those likely to be found in the oceans in 100 years due to anthropogenic emissions. They observed that the squid's routine oxygen consumption rate was reduced under these conditions, and their activity levels declined, presumably enough to have an effect on their feeding behavior.

Jumbo squid are an important predator in the eastern Pacific Ocean, and they are a large component of the diet of marine mammals, seabirds and fish.

As per Seibel, jumbo squid migrate between warm surface waters at night where CO₂ levels are increasing and deeper waters during the daytime where oxygen levels are extremely low.

"Squids suppress their metabolism during their daytime foray into hypoxia, but they recover in well-oxygenated surface waters at night," he said. "If this low oxygen layer expands into shallower waters, the squids will be forced to retreat to even shallower depths to recover. However, warming temperatures and increasing CO₂ levels may prevent this. The band of habitable depths during the night may become too narrow"......... Posted by: Kelly      Read more         Source

December 15, 2008, 5:25 AM CT

Practice as well as sleep may help birds learn new songs

Practice as well as sleep may help birds learn new songs.

The reorganization of neural activity during sleep helps young songbirds to develop the vocal skills they display while awake, University of Chicago scientists have found.

Sleep is well known to have a role in a broad range of learning processes studied in humans, including acquiring complex skills such as video game playing and learning new speech dialects. However, the neural mechanisms involved in the nighttime consolidation of learning are not well understood. To study this, scientists turned to an animal model system, the developmental learning of song in songbirds, which long has been known to share features with learning speech and language.

Sylvan Shank, a recent Ph.D. graduate in Psychology, and Daniel Margoliash, Professor in Organismal Biology & Anatomy and in Psychology, report in this week's issue of Nature that when young zebra finches listen to an adult tutor's song and then practice singing, the activity of premotor neurons in the brain is altered during the following night's sleep. The newly formed pattern of spikes in nighttime activity carries information both about the tutor song and auditory feedback the birds hear while singing. These nighttime changes lead to improvements the young birds' singing that can be observed the following day......... Posted by: Kelly      Read more         Source

December 11, 2008, 10:35 PM CT

Missing: 2,000 elephants

Elephants in Zakouma National Park, the last stronghold for the savanna elephants of Central Africa's Sahel region, now hover at about 1,000 animals, down from an estimated 3,000 in 2006. Ivory poachers using automatic weapons have decimated elephant populations especially when herds venture seasonally outside of the park.

Civil unrest in has made conservation exceedingly difficult in Chad. Several park guards have been shot and killed in recent years. However, safety conditions have recently improved somewhat and WCS is optimistic that it can increase on-the-ground elephant conservation work in and around Zakouma to protect the remaining population.

"The situation in Zakouma is dire, but there is still time to save the park's remaining elephants provided we can marshal the forces we need to stop poaching," said WCS President and CEO Dr. Steven E. Sanderson. "We need to continue to work closely with Zakouma's dedicated park guards and give them what they need to do their jobs, while our own field staff provide aerial reconnaissance and technical support".

WCS has established a fund to help save Zakouma's surviving elephants. Members of the public can support this critical effort by going to: www.wcs.org/elephants.

History has shown that elephants can recover in Zakouma. Until this recent spate in poaching, elephant numbers have rebounded from an estimated 1,100 in 1985 to as a number of as 3,500 in early 2006......... Posted by: Kelly      Read more         Source