Hawaiian Plant, Thought To Be Newcomer, Actually Shaped Ecology Of The Islands From The Beginning

The distinctly shaped flowers of the Metrosideros plant, known as “ohi’a” in its native Hawaii, share a symbiotic relationship with many of the islands birds, including this apapane, which pollinates the flower as it feeds on the nectar. Through research on a molecular level, scientists at the Smithsonian Institution believe these plants may have colonized the islands much earlier than once believed. Their data show that Metrosideros could have colonized the islands soon after they formed, creating specialized relationships with a number of birds and insects on the islands as they coevolved. (Credit: Jack Jeffrey / jackjeffreyphoto.com)

Scientists at the Smithsonian Institution have discovered data that suggests one of Hawaii’s most dominant plants, Metrosideros, has been a resident of the islands far longer than previously believed.

Metrosideros, commonly called “ohi’a” in the Hawaiian Islands, has puzzled researchers for years. Although previously thought to be a newcomer to the islands, these plants are well integrated into the islands’ ecosystems.

However, scientists from the Smithsonian’s National Museum of Natural History and the Smithsonian’s National Zoo now are able to show, through molecular research, that Metrosideros may have colonized the islands soon after they formed. If so, these plants would have played an important role in shaping the ecology of the islands from the beginning.

The isolated Hawaiian Islands are home to many unique and endemic species of plants and animals. To know how these species came to interact with one another and form functioning ecosystems, scientists must first know how and when each species came to be on the islands. This is particularly important in the case of Metrosideros–many species of birds and insects are specialized to coexist and feed on these plants. Knowing when Metrosideros dispersed and colonized the islands also will give scientists a better understanding of how and when the fauna that rely on them evolved.

Until now, no definitive phylogeographical study (combining evolutionary history with current distribution patterns in order to understand both) has been done on ecologically dominant species in this island group.

“What we are finding,” said Scott Miller, a Smithsonian scientist working on the project, “is a distinct geographical pattern that supports a hypothesis that these plants colonized the Hawaiian Islands sequentially as they formed.” This could prove that Metrosideros played a far more important role in Hawaii’s ecology than once thought.

Scientists at the Smithsonian will continue to research Metrosideros in Hawaii to further determine the plant’s historical colonization pattern and its influence and role in the biodiversity of the islands.

Their findings are being published in the journal Proceedings of the Royal Society B in London on April 16.

http://www.sciencedaily.com/releases/2008/04/080415210623.htm

More To Bats’ Vision Than Meets The Eye

The eyes of nocturnal bats possess two spectral cone photoreceptor types for daylight and colour vision. Scientists at the Max Planck Institute for Brain Research in Frankfurt and the University of Oldenburg have detected cones and their visual pigments in two flower-visiting species of bat. With electroretinographic recordings, they found an increased sensitivity to UV light in cone-stimulating light conditions.

The researchers conclude that bats’ eyes are adapted for both daylight and UV vision. The UV-sensitive cones may yield a number of advantages for bats, including improved visual orientation at twilight, predator avoidance and de tection of UV-reflecting flowers (a benefit for those that feed on nectar).

Bats are mammals in the order Chiroptera, which has two suborders: fruit bats (Megachiroptera) and microbats (Microchiroptera). Microbats (see images 1 and 2), also called ‘true bats,’ echolocate, while fruit bats do not. Microbats have small eyes and well developed visual centres in the brain. In bats, vision plays an important role in predator avoidance during foraging and homing and, in some species. in prey detection. Moreover, bats are exposed to different levels of ambient light during the day, depending on their roosting situation.

Mammalian retinas have rod photoreceptors for night vision and cone photoreceptors for daylight and colour vision. For colour discrimination, most mammals possess two cone populations with two visual pigments (opsins) that have absorption maxima at short wavelengths (S, blue or ultraviolet) and long wavelengths (L, green or red).

http://www.sciencedaily.com/releases/2009/07/090727203745.htm

Coral Algae Have “Eyes,” Study Says

The single-celled algae that set up house inside hard corals and give reefs their vibrant colors may be able to see, a new study says.

The algae—called zooxanthellae—have mysterious crystal-like deposits, which were found to be made of uric acid, a common element in light-reflecting structures in insect and animal eyes.

The substance in the algae had been previously misidentified as calcium oxalate, which is often found in plants, the researchers say.

The algae’s crystal clusters strongly reflected light in lab experiments, suggesting that “this is really a functional eye,” study co-author Kazuhiko Koike, of Japan’s Hiroshima University, said in an email.

Each of the single-celled orgamisms also contains a photoreceptor molecule, which creates an “eyespot.”

Eyespots are light-sensitive patches that allow simple organisms, such as jellyfish and some other algae, to sense their environments.

(Related: “Brittle Star Found Covered With Optically Advanced ‘Eyes.’”)

Four other types of dinoflagellates—one-celled aquatic organisms that include zooxanthellae—have eyespots, Koike said.

But he believes the newfound type of eyespot is unique to the coral-dwelling life-forms.

http://news.nationalgeographic.com/news/2009/07/090728-corals-eyes-algae.html

“LUCA” -Search for the Common Ancestor of All Life

Trying identify the “beginning” of life seems an impossible task. 

Just as linguists have been able to establish that all human languages have a common origin, so it turns out that all cellular life has a common origin. The ancestor of all life on Earth today has been dubbed LUCA, short for Last Universal Common Ancestor. The fact that there must have been a LUCA was first made clear in the 1960s when the genetic code was deciphered and found to be universal. In the forty years since the code was cracked, the emphasis is now on trying to reconstruct LUCA, but the emerging picture is substantially blurred by new insights into the evolutionary history of life. 

But an evolutionary geneticist from the Université de Montréal, together with researchers from the French cities of Lyon and Montpellier, published a ground-breaking study that characterizes the common ancestor of all life on earth, LUCA (last common ancestor).

The study changes ideas of early life on Earth. “It is generally believed that LUCA was a heat-loving or hyperthermophilic organism. A bit like one of those weird organisms living in the hot vents along the continental ridges deep in the oceans today (above 90 degrees Celsius),” says Nicolas Lartillot, the study’s co-author and a bio-informatics professor at the Université de Montréal. “However, our data suggests that LUCA was actually sensitive to warmer temperatures and lived in a climate below 50 degrees.”

The research team compared genetic information from modern organisms to characterize the ancient ancestor of all life on earth. “Our research is much like studying the etymology of modern languages so as to reveal fundamental things about their evolution,” says professor Lartillot. “We identified common genetic traits between animals, plant, bacteria, and used them to create a tree of life with branches representing separate species. These all stemmed from the same trunk – LUCA, the genetic makeup that we then further characterized.”

The group’s findings are an important step towards reconciling conflicting ideas about LUCA. In particular, they are much more compatible with the theory of an early RNA world, where early life on Earth was composed of ribonucleic acid (RNA), rather than deoxyribonucleic acid (DNA).

However, RNA is particularly sensitive to heat and is unlikely to be stable in the hot temperatures of the early Earth. The data of Dr. Lartillot with his collaborators indicate that LUCA found a cooler micro-climate to develop, which helps resolve this paradox and shows that environmental micro domains played a critical role in the development of life on Earth.

“It is only in a subsequent step that LUCA’s descendants discovered the more thermostable DNA molecule, which they independently acquired (presumably from viruses), and used to replace the old and fragile RNA vehicle. This invention allowed them to move away from the small cool microclimate, evolved and diversify into a variety of sophisticated organisms that could tolerate heat,” adds Dr. Lartillot.

http://www.dailygalaxy.com/my_weblog/2009/07/ancient-ancesto.html

A Better Way to Shoot Down Spam

Junk mail can now be identified based on a single packet of data.

New software developed at the Georgia Institute for Technology can identify spam before it hits the mail server. The system, known as SNARE (Spatio-temporal Network-level Automatic Reputation Engine), scores each incoming e-mail based on a variety of new criteria that can be gleaned from a single packet of data. The researchers involved say the automated system puts less of a strain on the network and minimizes the need for human intervention while achieving the same accuracy as traditional spam filters.

Separating spam from legitimate e-mail, also known as ham, isn’t easy. That’s partly because of the sheer volume of messages that need to be processed and partly because of e-mail expectations: users want their e-mail to arrive minutes, if not seconds, after it was sent. Analyzing the content of every e-mail might be a reliable method for identifying spam, but it takes too long, says Nick Feamster, an assistant professor at Georgia Tech who oversaw the SNARE research. Letting spam flow into our in-boxes unfiltered isn’t a sensible option, either. According to a report released by the e-mail security firm MessageLabs, spam accounted for 90.4 percent of all e-mail sent in June.

“If you’re not concerned about spam, I would suggest you turn off your spam filter for about an hour and see what happens,” says Sven Krassen, senior director of data-mining research at McAfee. The Santa Clara, CA, company provided raw data for analysis by the Georgia Tech team.

The team analyzed 25 million e-mails collected by TrustedSource.org, an online service developed by McAfee to collate data on trends in spam and malware. Using this data, the Georgia Tech researchers discovered several characteristics that could be gleaned from a single packet of data and used to efficiently identify junk mail. For example, their research revealed that ham tends to come from computers that have a lot of channels, or ports, open for communication. Bots, automated systems that are often used to send out reams of spam, tend to keep open only the e-mail port, known as the Simple Mail Transfer Protocol port.

http://www.technologyreview.com/communications/23086/

51 Headless Vikings Found in English Execution Pit?

Naked, beheaded, and tangled, the bodies of 51 young men—their heads stacked neatly to the side—have been found in a thousand-year-old pit in southern England, according to carbon-dating results released earlier this month.

The mass burial took place at a time when the English were battling Viking invaders, say archaeologists who are now trying to verify the identity of the slain.

(Related: ” Vikings’ Barbaric Bad Rap Beginning to Fade.”)

The dead are thought to have been war captives, possibly Vikings, whose heads were hacked off with swords or axes, according to excavation leader David Score of Oxford Archaeology, an archaeological-services company.

Announced in June, the pit discovery took place during an archaeological survey prior to road construction near the seaside town of Weymouth (map).

http://news.nationalgeographic.com/news/2009/07/090728-headless-viking-execution-pit.html

SPACE PHOTOS THIS WEEK: Space Eye, Jupiter Blast, More

Supernova remnant 1E 0102.2-7219, the debris of an exploded star, is seen in a new image combining data from the Chandra X-ray Observatory and the Hubble Space Telescope. The explosion would have been visible from Earth’s Southern Hemisphere more than a thousand years ago.

The picture marks the tenth anniversary of Chandra, which, shortly after blinking on, imaged the same explosion in 1999, though to decidedly drabber effect. (See more of Chandra’s “puffballs in outer space” and read more about the supernova remnants on Breaking Orbit.)

http://news.nationalgeographic.com/news/2009/07/photogalleries/week-in-space-pictures-53/photo4.html

Report finds fake antivirus on the rise

Malware posing as antivirus software is spreading fast with tens of millions of computers infected each month, according to a report to be released on Wednesday from PandaLabs. 

PandaLabs found 1,000 samples of fake antivirus software in the first quarter of 2008. In a year, that number had grown to 111,000. And in the second quarter of 2009, it reached 374,000, Luis Corrons, technical director of PandaLabs said in a recent interview.

“We’ve created a specific team to deal with this,” he said, of the rogue antivirus software that issues false warnings of infections in order to get people to pay for software they don’t need. The programs also typically download a Trojan or other malware.

PandaLabs found that 3 percent to 5 percent of all the people who scanned their PCs with Panda antivirus software were infected. Using that and worldwide computer stats from Forrester, PandaLabs estimates there could be as many as 35 million computers infected per month with rogue antivirus programs.

About 3 percent of the people who see the fake warnings fall for it, forking over $50 for an annual license or $80 for a lifetime license, according to Corrons.

Last September, a hacker was able to infiltrate rogue antivirus maker Baka Software and discovered that in one period an affiliate made more than $80,000 in about a week, said Sean-Paul Correll, a PandaLabs threat researcher.

A Finjan report from March estimated that fake antivirus distributors can make more than $10,000 a day

http://news.zdnet.com/2100-9595_22-325914.html.

After Dinosaurs, Mammals Rise But Their Genomes Get Smaller

New research suggests that only one group — mammals, like the mouse shown here — have seen their genomes shrink after the dinosaurs’ extinction. (Credit: iStockphoto/Margo VanLeeuwen)

Evidence buried in the chromosomes of animals and plants strongly suggests only one group — mammals — have seen their genomes shrink after the dinosaurs’ extinction. What’s more, that trend continues today, say Indiana University Bloomington scientists in the first issue of a new journal, Genome Biology and Evolution.

The scientists’ finding might seem counter-intuitive, given that the last 65 million years have seen mammals expand in diversity and number, not to mention dominance in a wide variety of ecological roles. But it is precisely their success in numbers that could have led to the contraction of their genomes.

“Larger population sizes make natural selection more efficient,” said IU Bloomington evolutionary biologist Michael Lynch, who led the study. “If we are correct, we have shown how to bring ancient genomic information together with the paleontological record to learn more about the past.”

And the present. Lynch says the data he and his colleagues analyzed suggest human genomes are still undergoing a contraction — though you shouldn’t expect to see noticeable changes in our chromosomes for a few million years yet.

http://www.sciencedaily.com/releases/2009/07/090727191919.htm

Is Hyper Evolution Possible? A Galaxy Classic

Think it takes thousands or even millions of years for animals to evolve significantly new traits? Think again. New research lends just a touch of credibility to the idea behind the popular sci-fi TV series Heroes, which portrays certain humans as having quickly evolved new astounding traits in response to increasingly tumultuous environmental pressures.  

In 1971 biologists moved 5 adult pairs of Italian wall lizards from their island home of Pod Kopiste, in the South Adriatic Sea, and introduced them to the neighboring island of Pod Mrcaru. An international team of researchers discovered that introducing these small, green-backed lizards, Podarcis sicula, to a new environment caused them to undergo shockingly fast and large-scale evolutionary changes.

Researchers returned to the islands twice a year for three years, in the spring and summer of 2004, 2005 and 2006. Captured lizards were transported to a field laboratory and measured for snout-vent length, head dimensions and body mass. Tail clips taken for DNA analysis confirmed that the Pod Mrcaru lizards were genetically identical to the source population on Pod Kopiste. In other words, there is no doubt that these lizards are the offspring of the 1971 transplant. The results of the study were recently published in Proceedings of the National Academy of Sciences.

The lizards evolved entirely new digestive system features to cope with dietary changes, evolved bigger heads and also ceased to defend territories—an instinct once very integral to the species behavior back on their original home territory. 

“Striking differences in head size and shape, increased bite strength and the development of new structures in the lizard’s digestive tracts were noted after only 36 years, which is an extremely short time scale,” remarks Duncan Irschick, a professor of biology at the University of Massachusetts Amherst.

Observed changes in head morphology were caused by adaptation to a different food source explains Irschick. The lizards on the barren island of Pod Kopiste were well-suited to catching mobile prey, feasting mainly on insects. Life on Pod Mrcaru, where they had never lived before, offered them an abundant supply of plant foods, including the leaves and stems from native shrubs. Analysis of the stomach contents of lizards on Pod Mrcaru showed that their diet included up to two-thirds plants, depending on the season, a large increase over the population of Pod Kopiste.

“As a result, individuals on Pod Mrcaru have heads that are longer, wider and taller than those on Pod Kopiste, which translates into a big increase in bite force,” says Irschick. “Because plants are tough and fibrous, high bite forces allow the lizards to crop smaller pieces from plants, which can help them break down the indigestible cell walls.”

Examination of the lizard’s digestive tracts revealed something even more surprising. Eating more plants caused the development of new structures called cecal valves, designed to slow the passage of food by creating fermentation chambers in the gut, where microbes can break down the difficult to digest portion of plants. Cecal valves, which were found in hatchlings, juveniles and adults on Pod Mrcaru, have never been reported for this species, including the source population on Pod Kopiste.

“These structures actually occur in less than 1 percent of all known species of scaled reptiles,” says Irschick. “Our data shows that evolution of novel structures can occur on extremely short time scales. Cecal valve evolution probably went hand-in-hand with a novel association between the lizards on Pod Mrcaru and microorganisms called nematodes that break down cellulose, which were found in their hindguts.”

Change in diet also affected the population density and social structure of the Pod Mrcaru population. Because plants provide a larger and more predictable food supply, there were more lizards in a given area on Pod Mrcaru. Food was obtained through browsing rather than the active pursuit of prey, and the lizards had given up defending territories.

“What is unique about this finding is that rapid evolution can affect not only the structure and function of a species, but also influence behavioral ecology and natural history,” says Irschick.

So next time you see Hayden Panettiere on TV running around in her cheer skirt regenerating her limbs, just think how the premise may be just slightly less crazy that you previously suspected.

http://www.dailygalaxy.com/my_weblog/2009/07/is-hyper-evolution-possible-a-galaxy-classic.html