Investigating Life in Extreme Environments report gives hints on life

Investigating Life in Extreme Environments report gives hints on life

From the deepest seafloor to the highest mountain, from the hottest region to the cold Antarctic plateau, environments labelled as extreme are numerous on Earth and they present a wide variety of features and characteristics.

Investigating life processes in extreme environments not only can provide hints on how life first appeared and survived on Earth (as early earth was an extreme environment) but it can also give indication for the search for life on other planets.

To examine these issues and other matters the European Science Foundation (ESF) has published a 58-page report Investigating Life in Extreme Environments – A European Perspective. Among other issues, the report has stated how global changes in the recent decades have turned some environments setting into becoming "extreme" conditions for the normal ecosystems ( e.g. acidification of the oceans). Therefore the understanding of tolerance/adaptation/non-adaptation to extreme conditions and ecosystem functioning are able to help predicting the impact of global change on biodiversity.

This report is resulted from an ESF inter-committee initiative involving the Marine Board (MB-ESF), the European Polar Board (EPB), the European Space Science Committee (ESSC), the Life Earth and Environmental Sciences Standing Committee (LESC), the Standing Committee for Humanities (SCH) and the European Medical Research Councils (EMRC). This interdisciplinary initiative considered all types of life forms (from microbes to humans) evolving in a wide range of extreme environments (from deep sea to acidic rivers, polar regions or planetary bodies).

A series of recommendations were made from a large-scale interdisciplinary workshop (128 participants) organised in November 2005 with an additional workshop organised in March 2006. They have identified interdisciplinary (listed below) and disciplinary research priorities.

Recommendations:

Cross-cutting Scientific Recommendations
• Identify and agree on i) model organisms in different phyla (a group that has genetic relationship) and for different extreme environments; and ii) model extreme environments
• Favour an ecosystem-based multidisciplinary approach when considering scientific activities in extreme environments.
• Foster the use of Molecular Structural Biology and Genomics when considering life processes in extreme environments

Cross-cutting Technology Recommendations
• Laboratory simulation techniques and facilities (e.g. microcosms) should be wider developed and made available to the scientific community.
• Develop of in-situ sampling, measurement and monitoring technologies. The assessment and use of existing techniques is also recommended.
• Adopt a common approach (specific to research activities in extreme environments) on technology requirements, availability and development.

Structuring and Networking the Science community
• Favorise interdisciplinarity and multidisciplinarity approaches between scientific domains and between the technological and scientific spheres.
• Create as soon as possible an overarching interdisciplinary group of experts to define the necessary actions to build a critical European mass in the field of "Investigating Life in Extreme Environments"
• Improve the information exchange, coordination and networking of the European community involved in scientific activities in extreme environments.

The report also includes recommendations specific to i) Microbial life, ii) Life Strategy of plants, iii) Life Strategy of animals and iv) Human adaptation.

1,000-year-old Arctic ponds disappearing due to global warming

1,000-year-old Arctic ponds disappearing due to global warming

Research has uncovered alarming evidence that high Arctic ponds, many which have been permanent bodies of water for thousands of years, are completely drying out during the polar summer. These shallow ponds, which dot the Arctic landscape, are important indicators of environment change and are especially susceptible to the effects of climate change because of their low water volume.

As published in the Proceedings of the National Academy of Sciences (PNAS), Marianne Douglas, Professor of Earth and Atmospheric Science and Director of the Canadian Circumpolar Institute at the University of Alberta, and John Smol, Professor of Biology at Queen's University, studied these unique Arctic ponds for the past 24 years, collecting detailed data such as water quality and water levels from approximately 40 ponds. Collectively, this data represents the longest record of systematic limnological (the science of the properties of fresh water) monitoring from the high Arctic.

Over the 24 years the researchers spent monitoring the ponds, they recorded evidence of recent lower water levels and changes in water chemistry consistent with an increase in evaporation/precipitation ratios (E/P) and warmer temperatures. Until recently, the ponds of the study sites were permanent features of the landscape, but in early July 2006, because of warming trends in the Arctic, several of the main study ponds dried up completely, whereas others had dramatically reduced water levels.

"It was quite shocking to see some of our largest study ponds dry up by early summer," said Douglas.

The ecological ramifications of these changes are likely severe and will be felt throughout the Arctic ecosystem, says Douglas. It would affect waterfowl habitat and breeding grounds, invertebrate population dynamics and food for insectivores and drinking water for animals, to name only a few.

"These surface water ponds are so important because they are often hotspots of biodiversity and production for microorganisms, plants and animals in this otherwise extreme terrestrial environment." said Douglas.

Giant, heat-loving penguins roamed Peru

Giant, heat-loving penguins roamed Peru

Giant prehistoric penguins? In Peru? It sounds more like something out of Hollywood than science, but a researcher from North Carolina State University along with U.S., Peruvian and Argentine collaborators has shown that two heretofore undiscovered penguin species reached equatorial regions tens of millions of years earlier than expected and during a period when the earth was much warmer than it is now.

Paleontologist Dr. Julia Clarke, assistant professor of marine, earth and atmospheric sciences at NC State with appointments at the North Carolina Museum of Natural Sciences and the American Museum of Natural History, and colleagues studied two newly discovered extinct species of penguins. Peruvian paleontologists discovered the new penguins' sites in 2005.

The research is published online the week of June 25 in Proceedings of the National Academy of Sciences. It was funded by the National Science Foundation Office of International Science and Engineering and the National Geographic Society.

The first of the new species, Icadyptes salasi, stood 5 feet tall and lived about 36 million years ago. The second new species, Perudyptes devriesi, lived about 42 million years ago, was approximately the same size as a living King Penguin (2 ½ to 3 feet tall) and represents a very early part of penguin evolutionary history. Both of these species lived on the southern coast of Peru.

These new penguin fossils are among the most complete yet recovered and call into question hypotheses about the timing and pattern of penguin evolution and expansion. Previous theories held that penguins probably evolved in high latitudes (Antarctica and New Zealand) and then moved into lower latitudes that are closer to the equator about 10 million years ago – long after significant global cooling that occurred about 34 million years ago.

"We tend to think of penguins as being cold-adapted species," Clarke says, "even the small penguins in equatorial regions today, but the new fossils date back to one of the warmest periods in the last 65 million years of Earth's history. The evidence indicates that penguins reached low latitude regions more than 30 million years prior to our previous estimates."

The new species are the first fossils to indicate a significant and diverse presence of penguins in equatorial areas during a period that predates one of the most important climatic shifts in Earth's history, the transition from extremely warm temperatures in the Paleocene and Eocene Epochs to the development of "icehouse" Earth conditions and permanent polar icecaps. Not only did penguins reach low latitudes during this warmer interval, but they thrived: more species are known from the new Peruvian localities than inhabit those regions today.

By comparing the pattern of evolutionary relationships with the geographic distribution of other fossil penguins, Clarke and colleagues estimate that the two Peruvian species are the product of two separate dispersal events. The ancestors of Perudyptes appear to have inhabited Antarctica, while those of Icadyptes may have originated near New Zealand.

The new penguin specimens are among the most complete yet discovered that show us what early penguins looked like. Both new species had long narrow pointed beaks – now believed to be an ancestral beak shape for all penguins. Perudyptes devriesi has a slightly longer beak than seen in some living penguins but the giant Icadyptes salasi exhibits a grossly elongated beak with features not known in any extinct or living species. This species' beak is sharply pointed, almost spear-like in appearance, and its neck is robustly built with strong muscle attachment sites. Icadyptes salasi is among the largest species of penguin yet described.

Although these fossils seem to contradict some of what we think we know about the relationship between penguins and climate, Clarke cautions against assuming that just because prehistoric penguins may not have been cold-adapted, living penguins won't be negatively affected by climate change.

"These Peruvian species are early branches off the penguin family tree, that are comparatively distant cousins of living penguins," Clarke says. "In addition, current global warming is occurring on a significantly shorter timescale. The data from these new fossil species cannot be used to argue that warming wouldn't negatively impact living penguins."

Marine worm opens new window on early cell development

Marine worm opens new window on early cell development

University of Oregon biologists studying a common ocean-dwelling worm have uncovered potentially fundamental insights into the evolutionary origin of genetic mechanisms, which when compromised in humans play a role in many forms of cancer.

Their research, appearing in the July issue of the journal Developmental Cell, also increases the visibility of a three-year effort at the UO to promote use of the bristle worm Platynereis dumerilii as a model organism for the study of evolutionary origins of cell types and animal forms.

The marine worm develops by a stereotypic pattern of asymmetric cell divisions generating differently sized embryonic cells. Platynereis dumerilii, the researchers wrote, "appears to have retained ancestral morphological and genomic features, including a slowly evolving protein complement," and, therefore, can be considered a living fossil.

"Our studies of this organism, called a polychaete annelid, a marine relative of earthworms, have provided potentially fundamental insights into the evolutionary origin of the genetic mechanisms that determine how different cell types are produced during animal embryogenesis," said lead author Stephan Q. Schneider, a postdoctoral researcher in the UO Institute of Molecular Biology.

The genetic mechanism, in this case, is the beta-catenin signaling pathway and its regulation after cell divisions. Beta-catenin is a cellular protein, which regulates cell proliferation and communication between cells.

"This ancient mechanism remains a central feature of animal development in all animals today, and malfunction of this mechanism in humans is associated with some of the most common and deadly forms of cancer, including colon cancer and melanoma," Schneider said.

Schneider and co-author Bruce Bowerman, a professor of molecular biology, identified a highly conserved beta-catenin in this ancient worm and documented the protein's subcellular accumulation in 390 cells produced during the division of fertilized eggs during 195 separate embryonic cell cycles.

Surprisingly, they said, they found an accumulation of beta-catenin in only one of the two daughter cells after each cell division. They showed that the regulation of beta-catenin accumulation forms a molecular switch between two new daughter cells, causing the cells to be different from one another. This universal mechanism operates in embryos as a binary decision-maker, creating an organism with a diversity of cell types.

Beta-catenin has been the focus of research in other model systems, such as mice, fruit flies and roundworms, but never in these ancient slowly evolving invertebrates used in the UO research. The protein appears to be conserved throughout the animal kingdom.

In humans suffering from a variety of cancers, a breakdown in the normal regulation of beta-catenin signaling is thought to be responsible for the growth of related tumors. Coupled with similar findings involving beta-catenin in the nematode Caenorhabditis elegans, a roundworm found in soil, the new UO report suggests an ancient metazoan origin and role for beta-catenin protein in the earliest stages of cellular development.

The findings, Bowerman said, suggest that the genetic pathway in the marine worm may be one of the earliest mechanisms used in embryogenesis to make cells adopt different roles during development. The worms used in the UO study originated from the Mediterranean.

"It is intriguing that key components of the widely conserved beta-catenin cell-signaling pathway appear to specify cell fate throughout development in an embryo that, given the invariance of the embryonic cell lineage and the prevalence of asymmetric cell divisions, has been viewed as a classic example of mosaic development," Schneider and Bowerman wrote in their conclusion.

There are some 10,000 species of polychaete annelids, dating back to the Paleozoic era, which started 542 million years ago. Polychaete refers to "many hairs" or "many bristles" that come off protrusions of the worms' bodies, which consist of fluid-filled tubes within tubes. These worms are bilaterally symmetrical with closed circulatory systems. Their ancient simplicity, Bowerman said, makes the Platynereis a rather uncomplicated model system for studying such protein interactions.

New Way to the Center of the Earth

New Way to the Center of the Earth

Humans have yet to see Earth's center, as did the characters in Jules Verne's science fiction classic, "Journey to the Center of the Earth." But a new NASA study proposes a novel technique to pinpoint more precisely the location of Earth's center of mass and how it moves through space.

Knowing the location of the center of mass, determined using measurements from sites on Earth's surface, is important because it provides the reference frame through which scientists determine the relative motions of positions on Earth's surface, in its atmosphere and in space. This information is vital to the study of global sea level change, earthquakes, volcanoes and Earth's response to the retreat of ice sheets after the last ice age.

The accuracy of estimates of the motion of Earth's center of mass is uncertain, but likely ranges from 2 to 5 millimeters (.08 to .20 inches) a year. Donald Argus of NASA's Jet Propulsion Laboratory, Pasadena, Calif., developed the new technique, which estimates Earth's center of mass to within 1 millimeter (.04 inches) a year by precisely positioning sites on Earth's surface using a combination of four space-based techniques. The four techniques were developed and/or operated by NASA in partnership with other national and international agencies. Results of the new study appear in the June issue of Geophysical Journal International.

Scientists currently define Earth's center in two ways: as the mass center of solid Earth or as the mass center of Earth's entire system, which combines solid Earth, ice sheets, oceans and atmosphere. Argus says there is room for improvement in these estimates.

"The past two international estimates of the motion of the Earth system's mass center, made in 2000 and 2005, differ by 1.8 millimeters (.07 inches) a year," he said. "This discrepancy suggests the motion of Earth's mass center is not as well known as we'd like."

Argus argues that movements in the mass of Earth's atmosphere and oceans are seasonal and do not accumulate enough to change Earth's mass center. He therefore believes the mass center of solid Earth provides a more accurate reference frame.

"By its very nature, Earth's reference frame is moderately uncertain no matter how it is defined," Argus said. "The problem is very much akin to measuring the center of mass of a glob of Jell-O, because Earth is constantly changing shape due to tectonic and climatic forces. This new reference frame takes us a step closer to pinpointing Earth's exact center."

Argus says this new reference frame could make important contributions to understanding global climate change. The inference that Earth is warming comes partly from observations of global sea level rise, believed to be due to ice sheets melting in Greenland, Antarctica and elsewhere. In recent years, global sea level has been rising faster, with the current rate at about 3 millimeters (.12 inches) a year. Uncertainties in the accuracy of the motion of Earth's center of mass result in significant uncertainties in measuring this rate of change.

"Knowing the relative motions of the mass center of Earth's system and the mass center of the solid Earth can help scientists better determine the rate at which ice in Greenland and Antarctica is melting into the ocean," Argus explained. He said the new frame of reference will improve estimates of sea level rise from satellite altimeters like the NASA/French Space Agency Jason satellite, which rely on measurements of the location and motion of the mass center of Earth's system.

"For scientists studying post-glacial rebound, this new reference frame helps them better understand how viscous [gooey or sticky] Earth's solid mantle is, which affects how fast Earth's crust rises in response to the retreat of the massive ice sheets that covered areas such as Canada 20,000 years ago," he said. "As a result, they'll be able to make more accurate estimates of these vertical motions and can improve model predictions."

Scientists can also use the new information to more accurately determine plate motions along fault zones, improving our understanding of earthquake and volcanic processes.

The new technique combines data from a high-precision network of global positioning system receivers; a network of laser stations that track high-orbiting geodetic satellites called Laser Geodynamics Satellites, or Lageos; a network of radio telescopes that measure the position of Earth with respect to quasars at the edge of the universe, known as very long baseline interferometry; and a French network of precise satellite tracking instruments called Doppler Orbit and Radiopositioning Integrated by Satellite, or DORIS.

Study of underground lakes in Antarctica could be critical, prof says

Study of underground lakes in Antarctica could be critical, prof says

Study of underground lakes in Antarctica could be critical, prof says

The discovery of interconnected lakes beneath kilometers of ice in Antarctica could be one of the most important scientific finds in recent years, but proper procedures need to be established before investigation begins, says a Texas A&M University scientist who is a leader in the research efforts. 

 

Mahlon "Chuck" Kennicutt II, professor of oceanography and director of the Sustainable Development Program in Texas A&M's Office of the Vice President for Research, says the National Science Foundation and 11 countries involved in the research and exploration are seeking agreement on how best to study these unique environments, which include at least 145 lakes under Antarctica's massive ice sheets. Several of the lakes are immense, and one, Lake Vostok, is similar in size to Lake Ontario, roughly 5,400 square miles, scientists note.

Participants in the project known as The Russian Antarctic Expedition have announced their intentions to penetrate Lake Vostok during the coming Antarctic field season.

"These lakes were rediscovered within the past 10 years or so, but no one yet has penetrated them and we want to make sure that the research is done properly and adheres to the highest environmental stewardship principles," says Kennicutt, who also serves as a director of the SALE (Subglacial Antarctic Lake Environments) office, which is maintained at Texas A&M.

"This has the potential to be one of the most important scientific discoveries in years, since sub-ice water appears to be an important player in many different processes fundamental to Antarctica and our planet.

"We believe that these lakes are part of an interconnected system that spans the entire Antarctic continent," he adds. "These bodies of water are several miles beneath the ice sheet which took millions of years to form, meaning these lakes have been undisturbed and disconnected from our atmosphere for hundreds of thousands of years. It is highly likely that unique microbial communities that we never knew existed are lake residents."

A group of scientists, including Kennicutt, who also serves as an adviser to the National Science Foundation, the agency that funds and oversees all U.S. science in Antarctica, will meet in Big Sky, Mont., this week to discuss research procedures for studying sub-ice environments. The meeting closely follows the release of a report by the National Academies on environmental issues related to sub-ice exploration that provides guidance for future lake penetration.

Scientists from the countries involved, which include the U.S., France, Italy, Japan, Russia, the United Kingdom and others, have concluded that lake entry and sampling will ultimately be necessary to accomplish the ambitious research objectives, Kennicutt notes.

"How to do this in the best way to preserve these environments and to be least invasive is a key question that needs further discussion," he notes.

"The countries involved have all agreed we must do as much as possible to avoid altering the lakes or causing any environmental damage."

Research in Antarctica has always had a special set of rules among nations.

It is the only continent on Earth that is managed through an international treaty signed by 45 countries representing two-thirds of the world's population. By unanimous consent of these nations, Antarctica has been viewed as a continent for science, research and peace.

The Department of State coordinates U.S. policy on Antarctica and works closely with the National Science Foundation, which administers and manages the U.S. Antarctic Program. Kennicutt also assists the NSF's Office of Polar Program.

"We are probably 3-5 years away from conducting U.S. research on these underground lakes," Kennicutt believes.

"We believe these lakes may exert important controls on large ice sheet movement and that they are just like above-groundwater systems and include a range of features such as streams, rivers and lakes, only they are under kilometers of ice. Once the U.S. becomes fully engaged in these research efforts, this will almost certainly be one of the dominant Antarctic research focus areas for at least the next decade, if not longer."