Study of poison frogs the first to show that the Andes Mountains have been a major source of diversity for the Amazon basin.

AUSTIN, Texas—Colorful poison frogs in the Amazon owe their great diversity to ancestors that leapt into the region from the Andes Mountains several times during the last 10 million years, a new study from The University of Texas at Austin suggests.

This is the first study to show that the Andes have been a major source of diversity for the Amazon basin, one of the largest reservoirs of biological diversity on Earth. The finding runs counter to the idea that Amazonian diversity is the result of evolution only within the tropical forest itself.

“Basically, the Amazon basin is a ‘melting pot’ for South American frogs,” says graduate student Juan Santos, lead author of the study. “Poison frogs there have come from multiple places of origin, notably the Andes Mountains, over many millions of years. We have shown that you cannot understand Amazonian biodiversity by looking only in the basin. Adjacent regions have played a major role.”

Santos and Dr. David Cannatella, professor of integrative biology, published their findings this month in the journal PLoS Biology.

It has been assumed that much of the evolution of biodiversity in the Amazon basin occurred over the last one to two million years, a mere snapshot in time.

Santos and Cannatella peered about 45 million years into the past using novel biogeographical techniques to create a deep evolutionary history of poison frogs in space and time. Because of the lack of an extensive fossil record for the tropical forest, their work used DNA sequences to discover the frogs’ evolutionary history.

The poison frogs, or dendrobatids, are diverse and widely distributed across the Neotropics, an area that includes Central and South America. The scientists created an evolutionary tree, or phylogeny, using 223 of the 353 species of poison frogs known from throughout this region.

In analyzing the evolutionary relationships among the poison frogs, they discovered that Amazonian diversity is the result of at least 14 dispersals of ancestral frogs into the region beginning about 23 million years ago.

All living Amazonian poison frogs evolved from these ancestors, most of which (11 dispersals) came from the Andes Mountains.

The Amazon basin has changed dramatically over that long time. A large inland system of water has come and gone, the Andes Mountains started their uplift (about 15 million years ago) and the Amazon River was formed (about nine million years ago).

Most of the frog dispersals from the Andes occurred between one and seven million years ago, when the modern tropical rainforest of the Amazon River basin was forming.

“There was a repeated dispersal of frogs from the foothills of the Andes after the extensive inland wetlands retreated from the Amazon,” says Santos.

These frogs then evolved into about 70 species found today in the Amazon basin.

The scientists also discovered that frogs have historically immigrated out of the Amazon basin to adjacent areas, and to and from other regions within the Neotropics.

Evolution and diversification of the poison frogs is ongoing, especially in the Amazon rainforest, the Chocó (a narrow region of tropical forest along the northwest Pacific Coast of South America) and in adjacent Central America.

Cannatella says many other tropical plants and animals in the Amazon may share this more complex geographical and temporal history with the poison frogs.

“The Amazon rainforest is not just gradually accumulating diversity over time,” says Cannatella. “Ancestral frog species moved into and out of the area, and we can predict that other organisms restricted to these wet tropical forests may show a similar pattern of dispersal, evolution and diversification.”

Source: University of Texas at Austin.

Animals have an astonishing ability to develop reliably, in spite of variable conditions during embryogenesis. New research, published in parallel this week in PLoS Biology and PLoS Computational Biology, addresses how living things can develop into precise, adult forms when there is so much variation present during their development stages. A team led by John Reinitz at Stony Brook University, and funded by the National Institutes of Health, shows how fruit fly embryos can “forget” initial incorrect versions of their body plan and develop into recognizable adult flies.

“Our results show that groups of genes can act on one another to reduce variation and highlights the importance of genetic networks in generating robust development,” said Dr. John Reinitz.

Canalization, a principle of developmental biology described more than 60 years ago by C.H. Waddington, is the property of embryonic development whereby genetic interactions can adjust biochemical reactions to bring about reliable developmental outcomes, despite variable conditions.

A great deal of progress has been made in understanding the buffering of genotypic and environmental variation, and individual mutations that reveal variation have been identified. However, the mechanisms by which genetic interactions produce canalization are not yet well understood, because this requires molecular data on multiple developmental determinants and models that correctly predict complex interactions.

“We make use of gene expression data at both high spatial and temporal resolution for the gap genes involved in the segmentation of the fruit fly Drosophila embryo,” said Dr. Reinitz. “We also apply a mathematical model to show that cross regulation among the gap genes is responsible for canalization in this system.” The model predicted specific interactions that cause canalization, and the prediction was validated in experiments.

“With canalization, if there is too much of one protein in the embryo, a network of genes could theoretically change the amount of that protein present, so that the outcome for the embryo was normal,” said Dr. Reinitz. “Since this principle was suggested, a great deal of progress has been made in understanding the buffering of variation, but the specific mechanisms by which genetic interactions contribute to canalization have remained unclear – until now.”

The authors started by measuring the concentrations of certain proteins in normal and mutant Drosophila embryos, at an early stage of development when the embryo looks like a hollow rugby ball. Each protein is synthesized from a gene, and each of the proteins measured has a regulatory role; they can turn their own gene – and others – on and off. The authors created a series of equations that could describe the diffusion of proteins and their action on their own gene and on other genes in the network. These equations show that a wide range of initial conditions (in terms of protein concentrations) lead to several possible final conditions. These final conditions, called fixed points, govern or describe the final state of the segmentation process for the fruit fly embryo. They do not allow for variability in the embryo, and they ‘forget’ the initial information. This mathematical property combined with their accuracy in describing the biological processes can be used towards the theoretical explanation for Waddington’s canalization model.

“This study is an example of how biology is becoming a precise and quantitative field, like physics,” says Reinitz.

Source: Public Library of Science.

For over twenty years, scientists have known that a normal protein in the brain, PrP, or prion protein, can turn harmful and cause deadly illnesses like Creutzfeldt-Jakob disease (CJD) in humans, and bovine spongiform encephalopathy (BSE) in cattle. What they could not explain is why large amounts of this normal protein are produced by our bodies in the first place. In a new study published in this week’s PLoS Biology, researchers from the University of Konstanz in Germany reveal that PrP indeed plays a beneficial role for the organism – PrP helps cells communicate with one another during embryonic development.

In prion diseases, what transforms the normal PrP protein into a life-threatening substance is the abnormal alteration of its chemical structure. Moreover, prions have the treacherous ability to replicate by imprinting their abnormal structure into healthy PrPs, thereby generating new pathogenic particles. While this “conversion” process explains how prions are disseminated, “An abnormal function of the prion protein is considered to be one of the reasons for neuronal degeneration,” explains Dr. Edward Málaga-Trillo, leader of the study in Konstanz. However, the normal function of PrP has remained an unsolved mystery for many years. Until now, all previous experiments in genetically modified mice had failed to provide conclusive evidence, as these animals lacking PrP seemed perfectly healthy. A dead end?

By no means. The scientists from Konstanz were able to show that the lack of PrP can cause clear physiological abnormalities in a living animal and the trick was to use the tiny zebrafish as a model.

When the researchers from Konstanz microinjected zebrafish eggs with morpholinos, DNA-like molecules that prevent the normal production of PrP, the treated zebrafish embryos were unable to develop normally and eventually died. The proteins in the fish embryos normally found at cell-to-cell contact sites disappeared, rendering these cells unable to communicate and carry out the differentiation program that shapes the major structures of the body, including the nervous system.

“We were then able to prove that PrP serves as a glue element, bringing cells together and keeping them in contact,” explains co-author Dr. Gonzalo Solis, member of the team at the laboratory of Prof. Claudia Stürmer. “When two neighboring cells make contact, they become able to exchange important signals that affect the function of a tissue in the body.”

Although the work by Málaga-Trillo, Solis, and colleagues does not offer an immediate cure for CJD or BSE, the team from Konstanz has fit together the first pieces of a complex puzzle, which may widen our understanding of prion diseases and provide hope for their effective treatment.

Source: Public Library of Science.

Credit: Illustration by Sandra Olsen, Carnegie Museum of Natural History

The earliest known domesticated horses were both ridden and milked according to a new report published in the March 6, 2009 edition of the journal Science. The findings by an international team of archaeologists could point to the very beginnings of horse domestication and help explain its early impacts on society.

Researchers from Carnegie Museum of Natural History, Pittsburgh, Pa., and the universities of Exeter and Bristol in the U.K., uncovered the evidence in Kazakhstan, the world’s largest landlocked country situated in Central Asia. Data gathered by archaeologists supports the hypothesis that the horse-rich area in the vast, semi-arid, grassy plains, or steppe zones, east of the Ural Mountains in Northern Kazakhstan, contributed largely to the development of two neighboring cultures, the Botai in north-central Kazakhstan and the Tersek in the west.

“Having a domesticated animal that could be eaten, milked, ridden, used as a pack animal and potentially for haulage would have had a tremendous impact on any society that initiated or adopted horse herds,” said Sandra Olsen, curator of anthropology at the Carnegie Museum of Natural History.

Olsen directed several archaeological teams that excavated sites in Kazakhstan from 1994-2002. Her work in the Botai Culture sites of Krasnyi Yar in 2000 and Vasilkovka in 2002 was supported by the National Science Foundation. Her earlier work in the region was supported by National Geographic.

Archaeologists say horse domestication may have begun in Kazakhstan about 5,500 years ago, about 1,000 years earlier than originally thought. Their findings also put horse domestication in Kazakhstan about 2,000 years earlier than that known to have existed in Europe.

The research team used various techniques to discover that horses provided food and milk, to show that domestic horses differed from wild horses from the same region, and to prove that horses were harnessed and possibly ridden in the fourth millennium B.C., in Kazakhstan.

Researchers used a novel method of analyzing residue from fat-soluble lipids found on ancient Botai pottery to find traces of fats from horse milk, leading to the conclusion that people consumed horse milk at the beginning of the Copper Age some 5,500 years ago. Mare’s milk is still a staple of consumption in Kazakhstan where it’s usually fermented into a slightly alcoholic drink called ‘koumiss.’

Additionally, examinations of ancient bone remains showed that horses were similar in shape to Bronze Age domestic horses but different from more ancient wild horses from the same region, suggesting that people selected wild horses for their physical attributes, which were exaggerated through breeding.

“It is quite surprising that the Tersek and Botai horse metacarpals differ significantly,” said Olsen. “The Tersek culture and the Botai culture are considered to be the same culture by many archaeologists–they are separated by just two days’ ride on horseback, and they’re very similar in terms of their material culture. To find there may have been a difference in the sizes of their horses was something that I did not expect.”

The team also used a technique to search for ‘bit damage’ caused by bridling or harnessing horses. Researchers found tell-tale traces of the use of a thong bridle on the gap between the teeth of the lower jaw. A thong bridle is simply a leather thong draped over this gap and knotted under the chin, with the trailing ends acting as the reins. Plains Indians called this a war bridle or racing bridle and it most likely is the type of bridle that was developed first.

“The domestication of horses is known to have had immense social and economic significance, advancing communications, transport, food production and warfare,” said the Science paper’s lead author, Alan Outram of Exeter. He said the findings are significant because they change “our understanding of how these early societies developed.”

Some comparisons can be made to the early horse-herder culture of the Plains Indians in America, but with some important differences. First, American Indians did not go through the process of capturing wild horses, taming them, and breeding them to become more well-mannered.

Instead, when the horse was re-introduced to North America by the Europeans–having evolved in North America, spread to Asia and Europe, before going extinct in the New World about 10,000 years ago–it was fully domesticated. “American Indians had the advantage of receiving an animal that was already selected to be more docile and controllable,” said Olsen.

“Although the Plains Indians often had to develop their own tack, harnesses and equipment used for riding, they often saw the bridles and other equipment that the Spaniards and other Europeans had.

“There is no question that there are similarities in the Plains Indian societies and some cultures on the Eurasian steppe that depended heavily on the horse, but we must take care in carrying that analogy too far,” Olsen said.

Source: National Science Foundation

Credit: Photo by Charles Hedgcock RBP

Moths need just the essence of a flower’s scent to identify it, according to new research from The University of Arizona in Tucson.

Although a flower’s odor can be composed of hundreds of chemicals, a moth uses just a handful to recognize the flower.

It’s like identifying a piece of music from hearing only the notes played by a few key instruments, said lead researcher Jeffrey A. Riffell.

“The moth isn’t paying attention to all the chemicals at the same time,” Riffell said. “It’s actually just paying attention to a few.”

The finding provides insight into how the brain processes a specific smell from the sea of odors floating through the air.

The UA team recorded from the brains of tobacco hornworm moths as they smelled each individual chemical of the 60-some that comprise the fragrance emitted by the moth’s preferred source of nectar, sacred datura flowers.

It is the first time researchers have recorded an insect’s brain activity as the animal smelled all the individual chemicals captured from a real flower. Previous research used only synthetic odors.

Just nine of the chemicals provoked a neural response. However, all nine had to be presented simultaneously for the moth to fly to the smell’s source and then stick out its tongue seeking nectar.

Riffell, Hong Lei and John G. Hildebrand of the UA’s Arizona Research Laboratories Division of Neurobiology and Thomas A. Christensen of UA’s department of speech, language and hearing sciences published their article, “Characterizing and Coding of Behaviorally Significant Odor Mixtures,” in the current issue of the journal Current Biology.

Capturing the scent of a sacred datura flower, Datura wrightii.

Credit: Jeffrey A. Riffell

The National Institutes of Health and the National Science Foundation funded the research.

How the brain-olfactory system decodes odor stimuli is not well understood.

“Two-thirds of the male moth’s brain is geared toward the environment,” Riffell said. “For female moths, it’s about 90 percent.”

Tobacco hornworm moths, known to scientists as Manduca sexta, are hawkmoths native to the Southwest. Their favorite nectar source is the sacred datura plant, known to scientists as Datura wrightii. Its white trumpet-shaped flowers bloom only at night. Female moths also lay their eggs on the plant, so to keep things simple, the team used only male moths for the study.

To find food, the moths must recognize the faintest whiff of datura smell and then track the scent upwind to the flower.

Riffell figured out how to capture the chemicals emitted by the flower and take them back to the lab.

He engulfed a flower with a Reynolds® Oven Bag and sucked the air out of the bag into a charcoal filter to snag all the odor chemicals. He snagged scent from 20 different plants.

Back in the lab, he created a solution of the chemicals and injected it into a gas chromatograph.

The chromatograph separated the chemicals and spewed them out one by one into a branched tube: one branch led to a wired-up moth and the other to a machine that identified and recorded the individual chemicals as they wafted by.

The set-up allowed the researchers to record the moths’ brain activity as the animals smelled the individual chemicals. The recording equipment was hooked up to a speaker. If the moth’s brain reacted, the researcher heard a rapid pop-pop-pop-pop sound, Riffell said.

Tobacco hornworm moth, Manduca sexta, seeks nectar from an filter-paper flower soaked in some chemicals from the scent of its favorite nectar source, the sacred datura flower, Datura wrightii.

Credit: Photo by Charles Hedgcock RBP

“Then you look and see what chemical is coming through at that time,” he said. The moths’ brains “popped” to only nine chemicals from sacred datura’s bouquet.

To see how moths behaved toward those chemicals, he put synthetic versions of them on an artificial flower made of white filter paper. Then he tested 420 moths by putting a paper flower at one end of a wind tunnel and a moth at the other.

The moths were indifferent to the chemicals if they were presented one at a time.

In contrast, if a real sacred datura flower was used, the moths flew right to it and stuck out their tongues.

When all nine chemicals that had made the moths’ brains “pop” were put on the paper flower, the moths behaved the same way.

“It was amazing — as soon as you combined the chemicals, the moth behaved like gangbusters,” Riffell said. “It flew upwind to the flower and stuck out its proboscis at the flower.”

He suspects that human noses and brains also work by homing in on just a few distinctive chemicals in any particular smell.

“For an important odor, I think that’s what we’re doing — for instance, when we smell coffee.”

Source: University of Arizona

Karl Bates and his colleagues in the palaeontology and biomechanics research group have reconstructed the bodies of five dinosaurs, two T. rex (Stan at the Manchester Museum and the Museum of the Rockies cast MOR555), an Acrocanthosaurus atokensis, a Strutiomimum sedens and an Edmontosaurus annectens.

The team, whose findings are published in the Public Library of Science journal PLoS ONE today (19th February 2009), found that the smaller Museum of the Rockies T. rex could have weighed anywhere between 5.5 and 7 tonnes, while the larger specimen (Stan) might have weighed as much as 8 tonnes.

Acrocanthosaurus atokensis was a large predatory dinosaur that looked like T. rex but with large spines on its back and roamed the earth much earlier in the mid Cretaceous period, around 110M years ago. The team suggest Acrocanthosaurus probably weighed in at a similar mass to MOR555 and other medium sized adult T. rex at about 6 tonnes.

The Strutiomimum sedens, whose name means “ostrich mimic”, lived alongside T. rex in the late Cretaceous period and probably weighed somewhere between 0.4 – 0.6 tonnes

The reconstruction of Edmontosaurus annectens, a plant-eating hadrosaur was based on a juvenile specimen, but still weighed in at between 0.8 – 0.95 tonnes. As adults, some hadrosaurs grew as big as T. rex, again living in the late Cretaceous period.

The team used laser scanning (LiDAR) and computer modelling methods to create a range of 3D models of the specimens, attempting to reconstruct their body sizes and shape as in life. The laser scanner images the full mounted skeleton, resulting in a detailed 3D model in which each bone retains its spatial position and articulation. This provides a high resolution skeletal framework around which the body cavity and internal organs such as stomach, lungs and air sacs can be reconstructed. This has allowed calculation of body segment masses, centres of mass and moments of inertia for each animal – all the information that is needed to analyse body movements.

Having created their ‘best-guess’ reconstruction of each animal, they then varied the volumes of body segments and respiratory organs to find the maximum plausible range of mass for the animals. Even scientists cannot be sure exactly how fat or thin animals like T. rex were in life, and the team were interested in exactly how broad the range of possible values were for body mass. They believe that the lower weight estimates are most likely to be correct as there is no good reason for the dinosaurs to weigh more than they need to as this would affect their speed, energy use and demands on the respiratory system.

The team also measured the body mass of an ostrich, as an existing subject that would show how accurate their technique was, and found the results to be correct.

They will now use the results to further investigate the locomotion of dinosaurs, specifically how they ran.

Karl said: “Our technique allows people to see and decide for themselves how fat or thin the dinosaurs might have been in life. You can see the skeleton with a belly. Anyone from a five-year-old to a Professor can see it and say, ‘I think this reconstruction is too fat or too thin’.

He added: “This study will help us in our research on how dinosaurs ran in 3-D rather than 2-D as in previous studies.

“Reconstructing more dinosaurs in such detail will allow us to examine changes in body mass and particularly centre of mass as they evolved. As we know, dinosaurs evolved into birds. As they did so, the centre of mass moved forward and different walking styles evolved. Although the dinosaurs we have reconstructed are not very close relatives of the birds, we can nevertheless see a small forwards movement in the position of the centre of mass from Acrocanthosaurus atokensis to the T. rex, which lies closer to modern birds on the evolutionary lines.”

Source: University of Manchester

ATHENS, Ohio – In the Mesozoic Era, 70 million years before birds first conquered the skies, pterosaurs dominated the air with sparrow- to Cessna-sized wingspans. Researchers suspected that these extinct reptiles sustained flight through flapping, based on fossil evidence from the wings, but had little understanding of how pterosaurs met the energetic demands of active flight.

A new study published today in the journal PLoS ONE by researchers from Ohio University, College of the Holy Cross and the University of Leicester explains how balloon-like air sacs, which extended from the lungs to inside the skeleton of pterosaurs, provided an efficient breathing system for the ancient beasts. The system reduced the density of the body in pterosaurs, which in turn allowed for the evolution of the largest flying vertebrates.

“We offer a reconstruction of the breathing system in pterosaurs, one that proposes the existence of a mechanism with the same essential structure to that of modern birds — except 70 million years earlier,” said study co-author Leon Claessens, an assistant professor of biology at the College of the Holy Cross.

The system would have facilitated the necessary gas exchange to enable sustained activity, added co-author Patrick O’Connor, an assistant professor of biomedical sciences at the Ohio University College of Osteopathic Medicine.

Claessens and O’Connor were inspired to conduct the study after David Unwin of the University of Leicester, then curator at the Natural History Museum in Berlin, showed them an extraordinarily preserved pterosaur in 2003. The scientists thought the specimen might finally shed light on how the animals powered sustained flight.

“The shape and size of the rib segments that articulate with the sternum indicate that the ribcage was mobile, contrary to previous ideas,” Claessens said.

Unique and previously unrecognized projections on the ribs provided important leverage for the muscles that power lung ventilation, he added.

Because fossils rarely preserve soft tissues, the research team conducted a comparative study that included pterosaurs, birds and crocodilians in order to get a better understanding of the relationships among air sacs, lung structure and the skeleton. By using X-ray movies and CT scans, the group characterized how the skeleton works to move air through the lungs in living animals, and also how to identify the signature traces left on bones that have been invaded by air sacs.

Not only do the extinct pterosaurs show evidence that their bones that were invaded by air sacs, but patterns of pneumaticity throughout the entire skeleton of different pterosaur species parallel trends identified in many living bird groups. For example, there is a direct relationship between the proportion of the skeleton invaded by air sacs and the absolute body size of an animal.

“Whereas small-bodied pterosaurs and birds typically pneumatize only a restricted part of the backbone, larger-bodied species routinely pneumatize most bones of the body, including the wing skeleton out to the ends of the fingers,” O’Connor said.

Such modifications of the skeleton would have reduced bone density and resolved a major problem with sustaining flight in large-bodied pterosaurs: the energetic cost of keeping a heavy body up in the air. Density reduction of the skeleton in pterosaurs may have been beneficial, particularly so in the aerial giants—just as it appears to be in the largest flying birds today.

Air sacs in birds also serve other purposes, such as for visual displays and the production of sound, the researchers said. The existence of an analogous air-sac system in pterosaurs highlights new areas of research in which paleobiologists can explore aspects of pterosaurian biology.

Source: Ohio University.

Stanford researchers help predict where the ‘icky’ stuff — fish urine, fecal matter and uneaten feed — will end up; Research is finding that the wastes are carried greater distances that previously assumed

If you are a fish eater, it’s likely that the salmon you had for dinner was not caught in the wild, but was instead grown in a mesh cage submerged in the open water of oceans or bays. Fish farming, a relatively inexpensive way to provide cheap protein to a growing world population, now supplies, by some estimates, 30 percent of the fish consumed by humans.

Two hundred and twenty species of finfish and shellfish are now grown in farms.

Intuitively, it seems a good idea—the more fish grown in pens, the fewer need be taken from wild stocks in the sea. But marine aquaculture can have some nasty side effects, especially when the pens are set near sensitive coastal environments. All those fish penned up together consume massive amounts of commercial feed, some of which drifts off uneaten in the currents. And the crowded fish, naturally, defecate and urinate by the tens of thousands, creating yet another unpleasant waste stream.

The wastes can carry disease, causing damage directly. Or the phosphate and nitrates in the mix may feed an algae bloom that sucks the oxygen from the water, leaving it uninhabitable, a phenomenon long associated with fertilizer runoff.

It has been widely assumed that the effluent from pens would be benignly diluted by the sea if the pens were kept a reasonable distance from shore, said Jeffrey Koseff, a professor of civil and environmental engineering and co-director of Stanford’s Woods Institute for the Environment. But early results from a new Stanford computer simulation based on sophisticated fluid dynamics show that the icky stuff from the pens will travel farther, and in higher concentrations, than had been generally assumed, Koseff said.

“What we’ve basically debunked is the old adage that ‘The solution to pollution is dilution,’ ” he said. “It’s a lot more complicated.”

The computer modeling (with new Stanford software that goes by the acronym SUNTANS) was conducted by Oliver Fringer, an assistant professor of civil and environmental engineering. He created a virtual coastal marine area resembling California’s Monterey Bay.

Previous software, he said, has not been up to the task of accurately predicting where the unhealthy effluent from fish pens will end up, and should probably not be used by state or federal regulators when they approve locations for fish farms.

Existing software is typically derived from models that attempt to describe the drift of effluent from sewage outfall pipes, even though the substances and situations are different from fish farms. (Sewage outflow, for example, is often warmer than the ocean water.)

The fine details of modeling the flow of dissolved fish poop from a submerged cage are not as simple as they may seem. The design of the cage itself can affect the outcome. How much of the current flows through the cage, and how much goes around? Does the moving water swirl into eddies at the edges of the pen? Even the effects of the rotation of the earth on the waste plume comes into play.

The fish farmer would prefer that currents flush out his pens frequently, but as those currents take out the garbage they might unfortunately deliver it to a mangrove ecosystem or a public beach. On the other hand, insufficient flow through the pen can create a “dead zone” on the ocean floor as the fecal matter and uneaten food pile up beneath the fish.

Fringer is designing his software so that it can be used to asses any site—Puget Sound, perhaps—where sufficient digital mapping of the area already exists. SUNTANS comes just in time, said Stanford oceans expert Rosamond Naylor, as federal and local officials begin spelling the details of new health and environmental regulations for fish pens.

Also participating in the research was former postdoctoral researcher Subhas Karan Venayagamoorthy, now at Colorado State University.

Source: Stanford University.

Credit: Russ Hopcroft, University of Alaska Fairbanks / CoML

Earth’s unique, forbidding ice oceans of the Arctic and Antarctic have revealed a trove of secrets to Census of Marine Life explorers, who were especially surprised to find at least 235 species live in both polar seas despite a distance of more than 13,000-kilometer distance in between.

The scientists found marine life that both poles apparently share in common include marathoners such as some great whales (blue, humpback, fin) and birds, but also worms, crustaceans, and angelic snail-like pteropods, the latter discoveries opening a host of future research questions about where they originated and how they wound up at both ends of the Earth. DNA analysis is underway to confirm whether the species are indeed identical.

Among many other findings, the scientists also documented evidence of cold water-loving species shifting towards both poles to escape rising ocean temperatures.

The discoveries are the result of a series of landmark, often perilous voyages conducted during International Polar Year, 2007-2008. Biologists braved waves of up to 16 meters (48 feet) while getting to and from the Antarctic while their Arctic colleagues often worked under the watchful eye of an armed lookout to protect them from polar bears.

This is a photo of sand fleas (amphipod crustaceans) under nearshore ice in the Beaufort Sea. Ice-associated amphipods are a major food source for Arctic cod, in turn the main prey for ice seals.

Credit: Photo credit: Shawn Harper, University of Alaska Fairbanks / COML

The studies by a global network of polar researchers have added substantially to human knowledge about the diversity, distribution and abundance of marine life, with results to be fully detailed in the world’s first Census report, to be released in London Oct. 4, 2010.

“The polar seas, far from being biological deserts, teem with an amazing quantity and variety of life,” says Dr. Ian Poiner, Chair of the Census Scientific Steering Committee. “Only through the co-operation of 500 people from more than 25 countries could the daunting environmental challenges be overcome to produce research of such unprecedented scale and importance. And humanity is only starting to understand the nature of these regions.”

The polar Census teams are documenting:

• The distribution of ocean animals – mapping their changing ranges and hotspots;
• The diversity of species (to date: 7,500 animals in the Antarctic and 5,500 in the Arctic, of a global marine life species total estimated at 230,000-250,000); and
• The abundance and sizes of major species groups at various levels in the food web, in order to gauge how they change over time;

Antarctic seafloor: a single bioregion, and a cold incubator for new species

Previously thought to be low in species diversity and abundance, CAML researchers and collaborators have amassed biological data from nearly 1 million locations. Those places include seafloors exposed to light for the first time in as much as 100,000 years when ancient ice shelf lids melted and disintegrated in recent years.

Led by Drs. Michael Stoddart and Victoria Wadley of the Australian Antarctic Division, and Dr. Colin Summerhayes, Executive Director of the Scientific Committee on Antarctic Research, the Census of Antarctic Marine Life (CAML, www.caml.aq ) coordinated 18 major research voyages during IPY (2007-2008). That compares with two or three expeditions in a normal year.

The extensive sampling has provided both an immediate picture of unexpectedly rich marine life around Antarctica and the means to test important theories.

Research in the 1970′s suggested separate bioregions around Antarctica. CAML’s efforts, however, reveal life on the seafloor encircling Antarctica forms a single biological province, even though 8,500 km of ocean separates opposite sides of the continent.

Scientists are now analyzing hundreds of open ocean (pelagic) samples from all compass points around Antarctica to establish whether, as suspected, marine life distribution has been evened by the churn of the Antarctic Circumpolar Current. That swift-flowing current circles the polar continent twice as fast as the Gulf Stream flows from the Gulf of Mexico towards Europe.

And they report species of cold-water snail (pteropods) migrating southward as ocean temperatures rise further north.

Meanwhile, the polar marine explorers were startled when molecular techniques revealed that glacial cycles over millions of years made the Antarctic the cold incubator of many species residing today in more northern waters.

Census researchers last year established that several octopus types have repeatedly colonized the deep sea, each migration coinciding with retreating Antarctic ice over 30 million years.

Today they theorize that the Antarctic also regularly refreshes the world’s oceans with new varieties of sea spiders, isopods (crustaceans related to shrimp and crabs), and others as well. They believe the new species evolve when expansions of ice cloister Antarctica; when the ice retreats, they radiate northward along the same pathways followed by the octopuses.

The abundance of Antarctic marine biodiversity is recorded in the SCAR-MarBIN database, which today contains close to 1 million marine life observations below the Antarctic Circle. About half of Antarctic species are found nowhere else on Earth.

Says Victoria Wadley: “One hundred years ago, Antarctic explorers like Scott and Shackleton saw mostly ice. In 2009, we see life everywhere.”

Elizabeth Siddon dives below the ice in the Canada Basin.

Credit: Shawn Harper, University of Alaska Fairbanks / CoML

The Arctic: changes recorded

Many global collaborators teamed with the Census’ project on Arctic Ocean Diversity (ArcOD, www.arcodiv.org ), led by Drs. Rolf Gradinger, Bodil Bluhm and Russ Hopcroft of the University of Alaska, and Dr. Andrey Gebruk of the Shirshov Institute, Moscow. Together they completed 14 IPY expeditions, including 10 cruises.

Field work will continue this summer, including a cruise to the Beaufort Sea to investigate the potentially important role sea ice ridges could play as a refuge for marine life if ice loss continues long-term.

ArcOD researchers say subtle effects on marine life distribution, abundance and diversity due to recent warming in the Arctic have started appearing, most notably:

• A rising ratio of warm water to cold water-loving amphipod crustaceans in Hornsund fjord in Norway’s Svalbard Island group (also called Spitsbergen, midway between Norway and the North Pole); and
• Documentation from the Chukchi Sea of range extensions to the north of at least three species – in two cases by up to 500 km – plus a growing number of snow crabs.

Meanwhile, researchers say smaller marine species are replacing larger ones in some Arctic waters. The reasons behind the shift are obscure but the implications for the Arctic food web may be profound.

The Census database known as OBIS (the Ocean Biogeographic Information System) today contains almost 1 million observations of more than 5,500 distinct taxa in Arctic waters, with more being added at an ever quickening pace.

Says Russ Hopcroft: “We have filled in major blank spots on the Arctic map, and continue to add more, though big unobserved areas remain.”

New technologies

New technologies are dramatically speeding Census research into the abundance, diversity and distribution of marine biodiversity.

Census researchers are using cell phone-like devices to learn about the distribution of large animals at both poles. For example, tracking devices fitted to narwhals, the ocean unicorn (www.eol.org/pages/328542), record their Arctic migrations and provide as a by-product a wealth of rich data on the status of polar oceans, lending a major assist to science. Seals (http://eol.org/pages/1052724), meanwhile, captured before and after observations of the 2008 collapse of a large part of Antarctica’s Wilkins ice shelf.

SCUBA divers were deployed for observations in heavy Arctic ice and advanced, deep water optical systems on Remotely Operated Vehicles (ROVs) enabled detailed studies of delicate marine animals too fragile to collect. Similar approaches recorded videos of penguins and seals under Antarctic ice.

And DNA sequences, or barcodes, will dramatically accelerate the cataloguing of life’s diversity, helping to identify new and cryptic species. In partnership with Canada’s University of Guelph, ArcOD, CAML, their sister project, the Census of Marine Zooplankton (CMarZ, www.cmarz.org), and others are collaborating in the Polar Barcode of Life project, with Belgium’s SCAR-MarBIN (www.scarmarbin.be) creating data storage, analysis and visualization tools. CAML is barcoding some 3,000 Antarctic species; ArcOD has barcoded about 300 to date. With a completed molecular catalog, analysis of genetic variation within polar marine environments and at different depths will be far quicker and easier.

Others among the 17 Census of Marine Life projects contributing to the progress of understanding in polar regions is the International Census of Marine Microbes (ICoMM, http://icomm.mbl.edu), which was recently able to sequence the DNA of more than 370,000 individual microbes living in 2-to-10 liter seawater samples drawn from 16 points around the Antarctic. Work is underway to distinguish the species captured.

The History of Marine Animal Populations (HMAP, www.hmapcoml.org) project researchers, meanwhile, studied monastic and government records dating back to the 1600s to reconstruct populations of walruses in the White and Barents seas.

Benefits to society accruing already from Census research include the identification of vulnerable marine habitats in the Southern Ocean, based on CAML information. Meanwhile, the marine component of a multi-national Circumpolar Biodiversity Monitoring Program (http://arcticportal.org/en/caff/cbmp) is in development with ArcOD participation.

Braving often bitter cold and perilous ocean conditions, the outstanding accomplishments of dedicated polar marine researchers have been honored recently in a number of countries. On a 2008 visit to Antarctica, for example, Brazilian President Luiz Inácio Lula da Silva, presented CAML scientist Dr. Lucia Campos with a national award for her work in that region. Researcher Dr. Angelika Brandt of Germany was awarded the prestigious biennial SCAR medal by the Scientific Committee on Antarctic Research. And Census scientists Drs. Eduardo Klein and Elizabeth Huck of the Universidad Simon Bolivar received Venezuela’s highest civilian honor for their studies of Antarctic biodiversity.

Photography by ArcOD team members has earned a place in galleries from Alaska to the Smithsonian Institution in Washington DC, and inspired an exhibition of paintings based on the images. CAML and ArcOD researchers, meanwhile, have both provided marine life photos used for stamps in Canada and Australia commemorating IPY.

Concludes Ian Poiner: “In these unique oceans, where the water temperature is colder at the surface than below, we are establishing the first benchmarks of marine biodiversity against which change may be measured, a significant polar year legacy for future generations. The significant investment of nations, the skills of scientists from the many ocean research disciplines, and the social network of the Census of Marine Life made it happen.”

Source: Census of Marine Life

Scientists have sequenced over seventy strains of yeast, the greatest number of genomes for any species.

“Analysing so many strains has helped us to bring the small branches of Darwin’s ‘Tree of Life’ into focus,” said Dr Steve James of the National Collection of Yeast Cultures (NCYC) at the Institute of Food Research.

“We can sift through billions of DNA bases to clearly spot a wild yeast or the mosaic genome of a recent hybrid,” says Dr Ian Roberts, leader of the NCYC research team and the collection’s curator.

“This is a valuable test bed for the 1000 genomes project, in which the genomes of 1000 people are being sequenced,” said Professor Ed Louis from the University of Nottingham. “This number of organisms has never been sequenced before.”

The basic machinery of yeast is surprisingly similar to that of humans, and the project is already helping experts to develop the tools necessary for studying human genetic variation. Yeast can also be used to develop and test new drugs, such as for cancer.

The analysis to be published in Nature on Wednesday enables the scientists to study genetics in much finer detail than was ever possible for Darwin. They are able to see the differences within a species and use this knowledge in understanding yeast biodiversity and exploiting it for human benefit.

“Amongst other things, this dataset will help us to understand how yeast probiotics contribute to gut health,” says Dr Roberts.

The scientists analysed strains that have long been associated with human activity (such as baking, wine and sake) and wild strains, mostly from oak bark. They found that rather than all being derived from one common ancestor, humans have domesticated yeast strains at many points in history and from many different sources.

The association between man and yeast stretches back thousands of years. Recent findings from the Malaysian rainforest of chronic intake of alcoholic nectar by wild treeshrews suggest that the association between fermented beverages and primates is ancient and not exclusive to humans.

Yeast production is a multi-billion dollar industry for brewing, baking, biofuel production, probiotics, and medical applications. The strains used in this study are publicly available alongside several thousand other yeasts at www.ncyc.co.uk.

The collection is supported at the IFR by the BBSRC and seeks to make yeast strains and knowledge available to industrial and academic scientists in an equitable and efficient manner. The IFR is an Institute of the Biotechnology and Biological Sciences Research Council (BBSRC).

Source: Norwich BioScience Institutes.