Some Butterfly Species Particularly Vulnerable to Climate Change

A recent study of the impact of climate change on butterflies suggests that some species might adapt much better than others, with implications for the pollination and herbivory associated with these and other insect species.

The research, published in Ecological Entomology, examined changes in the life cycles of butterflies at different elevations of a mountain range in central Spain. They served as a model for some of the changes expected to come with warming temperatures, particularly in mountain landscapes.

The researchers found that butterfly species which already tend to emerge later in the year or fly higher in the mountains have evolved to deal with a shorter window of opportunity to reproduce, and as a result may fare worse in a warming climate, compared to those that emerge over a longer time period.

"Insects and plants are at the base of the food pyramid and are extremely important, but they often get less attention when we are studying the ecological impacts of climate change," said Javier G. Illan, with the Department of Forest Ecosystems and Society at Oregon State University.

"We're already expecting localized extinctions of about one third of butterfly species, so we need to understand how climate change will affect those that survive," he said. "This research makes it clear that some will do a lot better than others."

Butterflies may be particularly sensitive to a changing climate, Illan said, and make a good model to study the broader range of ecological effects linked to insects. Their flight dates are a relevant indicator of future responses to climate change.

Read more at Science Daily

Sierra Nevada 200-Year Megadroughts Confirmed

The erratic year-to-year swings in precipitation totals in the Reno-Tahoe area conjures up the word "drought" every couple of years, and this year is no exception. The Nevada State Climate Office at the University of Nevada, Reno, in conjunction with the Nevada Drought Response Committee, just announced a Stage 1 drought (moderate) for six counties and a Stage 2 drought (severe) for 11 counties.

Reno, Lake Tahoe and the Sierra Nevada are no strangers to drought, the most famous being the Medieval megadrought lasting from 800 to 1250 A.D. when annual precipitation was less than 60 percent of normal. The Reno-Tahoe region is now about 65 percent of annual normal precipitation for the year, which doesn't seem like much, but imagine if this were the "norm" each and every year for the next 200 years.

Research by scientists at the University of Nevada, Reno and their partners at Scripps Institution of Oceanography in San Diego indicates that there are other instances of such long-lasting, severe droughts in the western United States throughout history. Their recent paper, a culmination of a comprehensive high-tech assessment of Fallen Leaf Lake -- a small moraine-bound lake at the south end of the Lake Tahoe Basin -- reports that stands of pre-Medieval trees in the lake suggest the region experienced severe drought at least every 650 to 1,150 years during the mid- and late-Holocene period.

"Using an arsenal of cutting edge sonar tools, remotely operated vehicles (ROVs), and a manned submersible, we've obtained potentially the most accurate record thus far on the instances of 200-year-long droughts in the Sierra," Graham Kent, director of the Nevada Seismological Laboratory said. "The record from Fallen Leaf Lake confirms what was expected and is likely the most accurate record, in terms of precipitation, than obtained previously from a variety of methods throughout the Sierra."

Kent is part of the University of Nevada, Reno and Scripps research team that traced the megadroughts and dry spells of the region using tree-ring analysis, shoreline records and sediment deposition in Fallen Leaf Lake. Using side-scan and multibeam sonar technology developed to map underwater earthquake fault lines such as the West Tahoe fault beneath Fallen Leaf Lake, the team also imaged standing trees up to 130 feet beneath the lake surface as well as submerged ancient shoreline structure and development. The trees matured while the lake level was 130 to 200 feet below its modern elevation and were not deposited by a landslide as was suspected.

The team, led by John Kleppe, University of Nevada, Reno engineering professor emeritus, published a paper on this research and is presenting its findings in seminars and workshops.

"The lake is like a 'canary in a coal mine' for the Sierra, telling the story of precipitation very clearly," Kent said. "Fallen Leaf Lake elevations change rapidly due to its unique ratio between catchment basin and lake surface of about 8 to 1. With analysis of the standing trees submerged in the lake, sediment cores and our sonar scanning of ancient shorelines, we can more accurately and easily trace the precipitation history of the region."

Water balance calculations and analysis of tree-ring samples undertaken by Kleppe, Kent and Scripps scientists Danny Brothers and Neal Driscoll, along with Professor Franco Biondi of the University's College of Science, suggest annual precipitation was less than 60 percent of normal from the late 10th century to the early 13th century. Their research was documented in a scientific paper, Duration and severity of Medieval drought in the Lake Tahoe Basin, published in the Quaternary Science Reviews in November 2011.

Tree-ring records and submerged paleoshoreline geomorphology suggest a Medieval low-lake level of Fallen Leaf Lake lasted more than 220 years. More than 80 trees were found lying on the lake floor at various elevations above the paleoshoreline.

"Although the ancient cycle of megadroughts seems to occur every 650 to 1150 years and the last one was 750 years ago, it is uncertain when the next megadrought will occur. With climate change upon us, it will be interesting to see how carbon dioxide loading in the atmosphere will affect this cycle," Kent said.

Read more at Science Daily

Astronomers Discover Faintest Distant Galaxy

Astronomers at Arizona State University have found an exceptionally distant galaxy, ranked among the top 10 most distant objects currently known in space. Light from the recently detected galaxy left the object about 800 million years after the beginning of the universe, when the universe was in its infancy.

A team of astronomers, led by James Rhoads, Sangeeta Malhotra, and Pascale Hibon of the School of Earth and Space Exploration at ASU, identified the remote galaxy after scanning a moon-sized patch of sky with the IMACS instrument on the Magellan Telescopes at the Carnegie Institution's Las Campanas Observatory in Chile.

The observational data reveal a faint infant galaxy, located 13 billion light-years away. "This galaxy is being observed at a young age. We are seeing it as it was in the very distant past, when the universe was a mere 800 million years old," says Rhoads, an associate professor in the school. "This image is like a baby picture of this galaxy, taken when the universe was only 5 percent of its current age. Studying these very early galaxies is important because it helps us understand how galaxies form and grow."

The galaxy, designated LAEJ095950.99+021219.1, was first spotted in summer 2011. The find is a rare example of a galaxy from that early epoch, and will help astronomers make progress in understanding the process of galaxy formation. The find was enabled by the combination of the Magellan telescopes' tremendous light gathering capability and exquisite image quality, thanks to the mirrors built in Arizona's Steward Observatory; and by the unique ability of the IMACS instrument to obtain either images or spectra across a very wide field of view. The research, published in the June 1 issue of The Astrophysical Journal Letters, was supported by the National Science Foundation (NSF).

This galaxy, like the others that Malhotra, Rhoads, and their team seek, is extremely faint and was detected by the light emitted by ionized hydrogen. The object was first identified as a candidate early-universe galaxy in a paper led by team member and former ASU postdoctoral researcher Hibon. The search employed a unique technique they pioneered that uses special narrow-band filters that allow a small wavelength range of light through.

A special filter fitted to the telescope camera was designed to catch light of narrow wavelength ranges, allowing the astronomers to conduct a very sensitive search in the infrared wavelength range. "We have been using this technique since 1998 and pushing it to ever-greater distances and sensitivities in our search for the first galaxies at the edge of the universe," says Malhotra, an associate professor in the school. "Young galaxies must be observed at infrared wavelengths and this is not easy to do using ground-based telescopes, since the Earth's atmosphere itself glows and large detectors are hard to make."

To be able to detect these very distant objects which were forming near the beginning of the universe, astronomers look for sources which have very high redshifts. Astronomers refer to an object's distance by a number called its "redshift," which relates to how much its light has stretched to longer, redder wavelengths due to the expansion of the universe. Objects with larger redshifts are farther away and are seen further back in time. LAEJ095950.99+021219.1 has a redshift of 7. Only a handful of galaxies have confirmed redshifts greater than 7, and none of the others is as faint as LAEJ095950.99+021219.1.

"We have used this search to find hundreds of objects at somewhat smaller distances. We have found several hundred galaxies at redshift 4.5, several at redshift 6.5, and now at redshift 7 we have found one," explains Rhoads. "We've pushed the experiment's design to a redshift of 7 -- it's the most distant we can do with well-established, mature technology, and it's about the most distant where people have been finding objects successfully up to now."

Malhotra adds, "With this search, we've not only found one of the furthest galaxies known, but also the faintest confirmed at that distance. Up to now, the redshift 7 galaxies we know about are literally the top one percent of galaxies. What we're doing here is to start examining some of the fainter ones -- thing that may better represent the other 99 percent."

Resolving the details of objects that are far away is challenging, which is why images of distant young galaxies such as this one appear small, faint, and blurry.

"As time goes by, these small blobs which are forming stars, they'll dance around each other, merge with each other and form bigger and bigger galaxies. Somewhere halfway through the age of the universe they start looking like the galaxies we see today -- and not before. Why, how, when, where that happens is a fairly active area of research," explains Malhotra.

Read more at Science Daily

Even Early Human Hands Left Prominent Ecological Footprints

Early human activity has left a greater footprint on today's ecosystem than previously thought, say researchers working at the University of Pittsburgh and in the multidisciplinary Long Term Ecological Research (LTER) Network, created by the National Science Foundation to conduct long time scale research on ecological issues that span huge geographical areas. Highlighted in the June issue of BioScience, the Pitt/LTER collaboration shows how historic human actions caused changes in nature that continue to reverberate throughout present-day ecosystems.

In the article, researchers take a retrospective look at the impact of human activity on LTER Network sites spanning states from Georgia to New Hampshire and propose methods for measuring the effects of such activity. The study of legacy effects is important because it provides insights into how today's actions can affect tomorrow's ecological systems, says Daniel Bain, coprincipal investigator at the Baltimore Ecosystem Study LTER Network site and an assistant professor in the Department of Geology and Planetary Science in Pitt's Kenneth P. Dietrich School of Arts and Sciences. Bain notes that decision makers at all levels, including those creating policy, need historical information about ecosystems to make more effective environmental policies. In a democracy, says Bain, a diverse group of stakeholders -- such as outdoor enthusiasts like Trout Unlimited, fiscal watchdog groups such as Common Cause, and individual landowners -- needs this kind of data to effectively engage in the management of common resources.

"Increasingly, we propose to manage our ecosystems with sophisticated and complicated strategies," Bain says. "For example, we are attempting to manage agricultural runoff by changing how streams and floodplains are arranged. However, while designing these strategies, we tend to address the most recent impacts rather than the entire history of impacts. This can lead to wasted effort and misuse of relatively limited resources."

Legacy effects from human activities are all around us, says Bain, but few people ever give them a thought. For example, urban systems accumulate a lot of human-made materials, some of which have large ecological footprints and will ultimately leave a legacy. Bain cites the example of lead, which has been banned from gasoline and paint in the United States for several decades but can remain in soils for much longer periods of time. "We should be careful about growing food close to roads or near old houses," he cautions.

In agriculture, areas that were plowed hundreds of years ago react differently to contemporary acid deposition from air pollutants when compared with adjacent unplowed areas. Similarly, our extensive use of cement may add substantial amounts of calcium to urban soils, although the ecological impact of this practice is not yet fully understood, Bain adds.

Indeed, many landscapes that provide baseline ecological data for evaluating environmental change were structured in part by previous human interactions, such as settlements and agricultural practices. To make sense of the observed ecological patterns on such landscapes, Bain says, we must know something of the history of the processes acting to shape those patterns. A recent example of the need for historical data associated with the impact of humans is the debate over global warming and its associated climate change -- the legacy of increased emissions of carbon dioxide and other greenhouse gases over millennia, but hugely accelerated since the industrial revolution and, especially, over the past several decades.

Bain points out that without a systematic collection of data recorded by the LTER Network, the broader geographical patterns of legacy effects would be much more difficult to detect. For example, scientists have discovered that recently glaciated areas have much less dirt accumulation than unglaciated areas. When Europeans first arrived in the eastern United States and dramatically changed local agricultural practices, eroded soil ultimately found its way into waterways. However, the glaciated areas produced less dirt, leaving less of an erosional signal in contrast to unglaciated areas, which lost more dirt and left such erosional legacies as buried valley bottoms and filled harbors. "In terms of policy, the management of glaciated and unglaciated areas requires different approaches," Bain says.

Nevertheless, Bain says, "although LTER sites have decades of data to draw from, we do not necessarily capture these changes, even with our best multidecade studies. It's hard to know what we might have been able to understand now had the LTER Network been established six or nine decades ago instead of three."

Read more at Science Daily

Bat, Bee, Frog Deaths May Be Linked

In recent years, diseases have ravaged through bat, honeybee and amphibian populations, and now animal experts suspect that shared factors may link the deaths, which are putting many species at risk for extinction.

The latest setback affects bats, given this week's announcement that the deadly fungal disease known as white-nose syndrome has been confirmed in already endangered gray bats. The illness, caused by the fungus Geomyces destructans, has mortality rates reaching up to 100 percent at some sites.

Simultaneously, Colony Collapse Disorder continues to kill honeybees, while yet another fungus, Batrachochytrium dendrobatidis, has wiped out more than 200 frog species across the world.

"It appears that many species are under an immense amount of stress, allowing opportunistic diseases to take hold," Rob Mies, executive director of the Organization for Bat Conservation, told Discovery News. "Life is far more complex, so a single cause is likely not the only explanation for the bat, bee and frog deaths. There could be five, six or more factors involved."

One is how humans may be helping fungal spread. According to the U.S. Fish & Wildlife Service, white-nose syndrome can be inadvertently transferred from people to bats.

"Some of the first caves in North America to be affected by white nose syndrome were in very high tourism areas," Mies said. "Somebody could have visited a cave in Europe wearing boots, and then brought back a tiny bit of mud on the boots containing dormant fungus."

He explained that the fungus, which is sensitive to body warmth, does not infect humans and most other animals. Bats experience a lower body temperature while hibernating, when the fungus can set in.

"It may eat into a bat's skin, even putting holes in it," Mies said. "The fungus can grow to a point where it winds up replacing the skin."

The amphibian fungus also attacks through the skin, causing an infected frog's skin to become up to 40 times thicker than usual, according to San Francisco State University biologist Vance Vredenburg, who recently conducted a study on the related disease, known as chytrid. Since frogs use their skin to absorb water and vital salts, such sodium and potassium, infection often leads to death.

Other human factors tied to the bat, frog and bee deaths include the use of chemical pesticides that may be absorbed through the skin, climate change, habitat loss and the spread of other health threats, such as viruses and mites.

Helene Marshall of Marshall's Farm Natural Honey told Discovery News that "the virus causing CCD came to us when U.S. beekeepers were importing Australian packaged bees to meet the high pollination demand of the almond growers here in California."

Both bees and bats are critical to agriculture. Bats, like bees, can help to pollinate. They are also a primary predator of agricultural and other insect pests, such as mosquitoes. Frogs additionally consume insect pests.

The U.S. Fish & Wildlife Service now has a national plan for managing white-nose syndrome in bats. It allows for diagnostics, disease management, disease surveillance and more. But Mies points out that for animals like bats and frogs, antifungals can be "pretty nasty medicines," doing damage of their own and perhaps further damaging ecosystems.

Read more at Discovery News

Lip Smacks of Monkeys Prelude to Speech?

Monkeys smack their lips during friendly face-to-face encounters, and now a new study says that this seemingly simple behavior may be tied to human speech.

Previously experts thought the evolutionary origins of human speech came from primate vocalizations, such as chimpanzee hoots or monkey coos. But now scientists suspect that rapid, controlled movements of the tongue, lips and jaw -- all of which are needed for lip smacking -- were more important to the emergence of speech.

For the study, published in the latest Current Biology, W. Tecumseh Fitch and colleagues used x-ray movies to investigate lip-smacking gestures in macaque monkeys. Mother monkeys do this a lot with their infants, so it seems to be kind of an endearing thing, perhaps like humans going goo-goo-goo in a baby's face while playing. (Monkeys will also vibrate their lips to make a raspberry sound.)

Monkey lip-smacking, however, makes a quiet sound, similar to "p p p p". It's not accompanied by phonation, meaning sound produced by vocal cord vibration in the larynx.

Fitch, who is head of the Department of Cognitive Biology at the University of Vienna, and his team determined that lip-smacking is a complex behavior that requires rapid, coordinated movements of the lips, jaw, tongue and the hyoid bone (which provides the supporting skeleton for the larynx and tongue).

The smacks occur at a rate of about 5 cycles per second, and that's the clincher. It's the exact same rate as for average speed human speech, and much faster than chewing movements (about 2.5 cycles per second).

Read more at Discovery News

NASA Preparing to Launch Its Newest X-Ray Eyes

NASA's Nuclear Spectroscopic Telescope Array, or NuSTAR, is being prepared for the final journey to its launch pad on Kwajalein Atoll in the central Pacific Ocean. The mission will study everything from massive black holes to our own sun. It is scheduled to launch no earlier than June 13.

"We will see the hottest, densest and most energetic objects with a fundamentally new, high-energy X-ray telescope that can obtain much deeper and crisper images than before," said Fiona Harrison, the NuSTAR principal investigator at the California Institute of Technology in Pasadena, Calif., who first conceived of the mission 20 years ago.

The observatory is perched atop an Orbital Sciences Corporation Pegasus XL rocket. If the mission passes its Flight Readiness Review on June 1, the rocket will be strapped to the bottom of an aircraft, the L-1011 Stargazer, also operated by Orbital, on June 2. The Stargazer is scheduled to fly from Vandenberg Air Force Base in central California to Kwajalein on June 5 to 6.

After taking off on launch day, the Stargazer will drop the rocket around 8:30 a.m. PDT (11:30 a.m. EDT). The rocket will then ignite and carry NuSTAR to a low orbit around Earth.

"NuSTAR uses several innovations for its unprecedented imaging capability and was made possible by many partners," said Yunjin Kim, the project manager for the mission at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "We're all really excited to see the fruition of our work begin its mission in space."

NuSTAR will be the first space telescope to create focused images of cosmic X-rays with the highest energies. These are the same types of X-rays that doctors use to see your bones and airports use to scan your bags. The telescope will have more than 10 times the resolution and more than 100 times the sensitivity of its predecessors while operating in a similar energy range.

The mission will work with other telescopes in space now, including NASA's Chandra X-ray Observatory, which observes lower-energy X-rays. Together, they will provide a more complete picture of the most energetic and exotic objects in space, such as black holes, dead stars and jets traveling near the speed of light.

"NuSTAR truly demonstrates the value that NASA's research and development programs provide in advancing the nation's science agenda," said Paul Hertz, NASA's Astrophysics Division director. "Taking just over four years from receiving the project go-ahead to launch, this low-cost Explorer mission will use new mirror and detector technology that was developed in NASA's basic research program and tested in NASA's scientific ballooning program. The result of these modest investments is a small space telescope that will provide world-class science in an important but relatively unexplored band of the electromagnetic spectrum."

NuSTAR will study black holes that are big and small, far and near, answering questions about the formation and physics behind these wonders of the cosmos. The observatory will also investigate how exploding stars forge the elements that make up planets and people, and it will even study our own sun's atmosphere.

The observatory is able to focus the high-energy X-ray light into sharp images because of a complex, innovative telescope design. High-energy light is difficult to focus because it only reflects off mirrors when hitting at nearly parallel angles. NuSTAR solves this problem with nested shells of mirrors. It has the most nested shells ever used in a space telescope: 133 in each of two optic units. The mirrors were molded from ultra-thin glass similar to that found in laptop screens and glazed with even thinner layers of reflective coating.

The telescope also consists of state-of-the-art detectors and a lengthy 33-foot (10-meter) mast, which connects the detectors to the nested mirrors, providing the long distance required to focus the X-rays. This mast is folded up into a canister small enough to fit atop the Pegasus launch vehicle. It will unfurl about seven days after launch. About 23 days later, science operations will begin.

Read more at Science Daily

Mystery of Monarch Butterfly Migration Takes New Turn

During the fall, hundreds of millions of monarch butterflies living in eastern North America fly up to 1,500 miles to the volcanic forests of Mexico to spend the winter, while monarchs west of the Rocky Mountains fly to the California coast. The phenomenon is both spectacular and mysterious: How do the insects learn these particular routes and why do they stick to them?

A prevailing theory contends that eastern and western monarchs are genetically distinct, and that genetic mechanisms trigger their divergent migratory paths.

An analysis led by Emory University biologists, however, finds that the two groups of monarchs are genetically mixed. Their research, published in the journal Molecular Ecology, suggests that environmental factors may be the key to the butterflies' choice of winter homes, and to where they wind up in the spring.

"Our data gives the strongest signal yet that the eastern and western monarchs belong to a single genetic population," says Emory biologist Jaap de Roode, who led the research. "This distinction is important to help us better understand the behavior of the organism, and to conserve the monarch flyways."

In addition to researchers in the de Roode lab, the study involved a scientist from the Institute of Integrative Biology in Zurich, Switzerland.

Biologists have long been fascinated by the innate and learned behaviors underlying animal migrations. When monarchs are breeding, for instance, they can live up to four weeks, but when they are migrating, they can live as long as six months.

"As the day length gets shorter, their sexual organs do not fully mature and they don't put energy into reproduction. That enables them to fly long distances to warmer zones, and survive the winter," de Roode says. "It's one of the basic lessons in biology: Reproduction is very costly, and if you don't use it, you can live much longer."

Mass movements of animals have huge ecological impacts. They are also visually arresting, from the spectacle of giant herds of wildebeest trekking across the Serengeti to hundreds of thousands of sandhill cranes flocking along the banks of Nebraska's Platte River.

In the case of long-lived mammals and birds, the younger animals may learn some of the behaviors associated with migration. That's not the case with the monarchs, notes Amanda Pierce, a graduate student in Emory's Population Biology, Ecology and Evolution program, and a co-author of the study.

"We know there is no learning component for the butterflies, because each migration is separated by two to three generations," Pierce says. "To me, that makes the problem even more interesting. How can these small, delicate animals travel thousands of kilometers and arrive at the same destination as their great-great grandparents?"

The question of whether eastern and western monarchs are genetically the same has been hotly debated, and may be an essential piece to the puzzle of their divergent migration patterns.

The researchers used 11 genetic markers to compare the genetic structures of eastern and western monarchs, as well as non-migratory monarch populations in Hawaii and New Zealand. The results showed extensive gene flow between the eastern and western monarchs, and a genetic divergence between these North American butterflies and those from Hawaii and New Zealand.

"In a sense, the genetic markers provide a DNA 'fingerprint' for the butterflies," de Roode says. "Just by looking at this fingerprint, you can easily separate the butterflies of North America from those in Hawaii and New Zealand, but you can't tell the difference between the eastern and western monarchs."

The Emory researchers have now joined a project headed by Harvard, which also involves the University of Georgia and the University of Massachusetts, to sequence the full genomes of monarch butterflies from places around the world. That data should rule out genetic differences between the eastern and western monarchs, or reveal whether any smaller genetic differences, beyond the 11 markers used in the study, may be at play between the two groups.

The idea that eastern and western monarchs are distinct populations has been bolstered by tagging-and-tracking efforts based in the United States. That data, gathered through citizen science, indicates that the butterflies stay on separate sides of the Rocky Mountains -- a formidable high-altitude barrier.

De Roode, however, theorizes that when spring signals the eastern monarchs to leave the overwintering grounds in Mexico, they may simply keep radiating out, reproducing and expanding as long as they find milkweed plants, the food for their caterpillars.

"Few people have tagged the monarchs within Mexico to see where they go," he says, "because Mexico doesn't have as much citizen science as the U.S."

If the theory is correct, some of the monarchs leaving Mexico each spring may wind up in western North America, while others may filter into the eastern United States. This influx to the western U.S. could be crucial to survival of monarchs on that side of the continental divide.

"There are far fewer monarchs west of the Rockies," de Roode says. He notes that all of the overwintering monarchs on a typical overwintering site along the California coast consist of about the same number clustered onto a single big tree in Mexico's Monarch Butterfly Biosphere Reserve, where hundreds of millions of monarchs blanket the landscape in the winter.

The monarch butterfly migration has been called an endangered phenomenon, due to the loss of habitat along the routes. The Mexican overwintering sites, located in the Trans-Mexican Volcanic Belt region northwest of Mexico City, particularly suffer from deforestation. Drug trafficking in the region has decimated eco-tourism and hampered efforts to protect the trees.

"We hope our research can aid in the conservation of the monarch flyways," de Roode says.

Raising monarchs for release at weddings, memorials and other events is a growing industry, but U.S. Department of Agriculture regulations restrict shipping the butterflies across state lines.

Read more at Science Daily

Modern Birds Are Really Baby Dinosaurs

Modern birds retain the physical characteristics of baby dinosaurs, according to a new Nature study that found birds are even more closely related to dinos than previously thought.

Depending on the non-avian dinosaur and bird compared, that might be hard to believe. A toothy, angry reconstruction of Tyrannosaurus rex, for example, on first glance looks little like a common garden blue jay.

When researchers go beyond the surface to the tissue and skull levels, however, the similarities become more obvious.

Harvard University's Arkhat Abzhanov, associate professor of organismic and evolutionary biology, and Bhart-Anjan Bhullar, a Ph.D. student in Abzhanov laboratory and the first author of the study, did just that and found evidence that the evolution of birds is the result of a drastic change in how dinosaurs developed. Rather than take years to reach sexual maturity, as many dinosaurs did, birds sped up the clock (some species take as little as 12 weeks to mature), allowing them to lock into their baby dinosaur look.

"What is interesting about this research is the way it illustrates evolution as a developmental phenomenon," Abzhanov was quoted as saying in a press release. "By changing the developmental biology in early species, nature has produced the modern bird –- an entirely new creature –- and one that, with approximately 10,000 species, is today the most successful group of land vertebrates on the planet."

"The evolution of the many characteristics of birds –- things like feathers, flight, and wishbones -– has traditionally been a difficult problem for biologists," Mark Norell, chair of the division of paleontology at the American Museum of Natural History and one of the paper's co-authors, added.

"By analyzing fossil evidence from skeletons, eggs, and soft tissue of bird-like dinosaurs and primitive birds, we've learned that birds are living theropod dinosaurs, a group of carnivorous animals that include Velociraptor," Norell continued. "This new work advances our knowledge by providing a powerful example of how developmental changes played a major role in the origin and evolution of birds."

Read more at Discovery News

Milky Way Doomed to Crash with Andromeda

Four billion years from now, the Milky Way galaxy as we know it will cease to exist.

Our Milky Way is bound for a head-on collision with the similar-sized Andromeda galaxy, researchers announced today (May 31). Over time, the huge galactic smashup will create an entirely new hybrid galaxy, one likely bearing an elliptical shape rather than the Milky Way's trademark spiral-armed disk.

"We do know of other galaxies in the local universe around us that are in the process of colliding and merging," Roeland van der Marel, of the Space Telescope Science Institute in Baltimore, told reporters today. "However, what makes the future merger of the Andromeda galaxy and the Milky Way so special is that it will happen to us."

Astronomers have long known that the Milky Way and Andromeda, which is also known as M31, are barrelling toward one another at a speed of about 250,000 mph (400,000 kph). They have also long suspected that the two galaxies may slam into each other billions of years down the road.

However, such discussions of the future galactic crash have always remained somewhat speculative, because no one had managed to measure Andromeda's sideways motion —  a key component of that galaxy's path through space.

But that's no longer the case.

Van der Marel and his colleagues used NASA's Hubble space telescope to repeatedly observe select regions of Andromeda over a seven-year period. They were able to measure the galaxy's sideways (or tangential) motion, and they found that Andromeda and the Milky Way are indeed bound for a direct hit.

"The Andromeda galaxy is heading straight in our direction," van der Marel said. "The galaxies will collide, and they will merge together to form one new galaxy." He and his colleagues also created a video simulation of the Milky Way crash into Andromeda.

That merger, van der Marel added, begins in 4 billion years and will be complete by about 6 billion years from now.

A future cosmic crash

Such a dramatic event has never occurred in the long history of our Milky Way, which likely began taking shape about 13.5 billion years ago.

"The Milky Way has had, probably, quite a lot of small, minor mergers," said Rosemary Wyse of Johns Hopkins University in Baltimore, who was not affiliated with the new study. "But this major merger will be unprecedented."

The merger poses no real danger of destroying Earth or our solar system, researchers said. The stretches of empty space separating the stars in the two galaxies will remain vast, making any collisions or serious perturbations unlikely.

However, our solar system will likely get booted out to a different position in the new galaxy, which some astronomers have dubbed the "Milkomeda galaxy." Simulations show that we'll probably occupy a spot much farther from the galactic core than we do today, researchers said.

A new night sky

And the collision will change our night sky dramatically. If any humans are still around 3.75 billion years from now, they'll see Andromeda fill their field of view as it sidles up next to our own Milky Way. For the next few billion years after that, stargazers will be spellbound by the merger, which will trigger intense bouts of star formation.

Finally, by about 7 billion years from now, the bright core of the elliptical Milkomeda galaxy will dominate the night sky, researchers said. (The odds of viewing this sight, at least from Earth, are pretty slim, since the sun is predicted to bloat into a huge red giant 5 or 6 billion years from now.)

Read more at Discovery News