By: James FennerResearchers have recently identified signs of life stirring beneath the icy depths of Antarctica. Samples taken from an ice-covered lake suggest that small microorganisms may have managed to live under the most extraordinary and harshest of conditions. The results could offer insight into the existence of other types of bacteria that may exist on Earth, as well as those of distant planets.An International Race
Several teams have recently been involved in a frantic race to expose some of the vast networks and streams that lie beneath the Antarctic. These great lakes were recently discovered to experience a cyclic filling and emptying of water, loosening up sections of ice and transporting them towards the ocean. This, in turn, is believed to contribute towards the melting of large sections of ice, leading to a tangible rise in global sea levels.
Back in 2007, a glaciologist described a new underground world beneath the Antarctica, involving subglacial lakes and interconnecting water streams. The shear scope and magnitude of these routes had yet to be mapped extensively, but satellite imagery was beginning to provide clues of the intermittent nature of the rise and fall of an ice surface, over what is now known to be Lake Whillans. This remarkable finding was made by a research team, led by Helen Fricker, a glaciologist working for the Scripps Institution of Oceanography.
The implications of these discoveries are significant for understanding the influence of global warming, and rising sea levels. Although these lakes are not directly impacted by the phenomenon, their interaction with the region’s ice sheets is alleged to carry ice to sea and induce melting events.
Ancient Life of Lake Hodgson
A collection of scientists from various organizations, including those of the British Antarctic Survey, have managed to successfully drill through an ice sheet covering Lake Hodgson, located on the Antarctic Peninsula. Today, the lake is covered by as little as two feet of ice, contrasted against well in excess of a 1,000 feet of ice present thousands of years back in time.
The scientists then began to collect samples of sediment at the bottom of the Antarctic lake. These samples were taken back to the laboratory and a series of cultures were performed, revealing the existence of ancient life. When genetic sequence comparisons were conducted, a huge range of matches to existing bacteria were identified, including a number of extremophiles, which are capable of living in some of the harshest conditions.
However, according to the researchers’ article, which was published in Diversity, the bacteria contains some unique genetic sequences:
“… only 77% of sequences identified could be matched to a known sequence, species or type strain, suggesting that a vast amount of novel biodiversity is present.”
As for the finding of extremophile bacteria, the authors posit a number of potential sources, including either active or inactive hydrothermal vents, arising from depths of the ice, possibly due to the existence of volcano-glacial interactions.
On the other hand, the group has also suggested that these bacteria could have originated from deep within the Earth’s crust, “… via fissures and groundwater movements.”
Lake Whillans
A science team from the United States breached the ice above Lake Whillans in January of this year, revealing the heart of a hidden lake, from which samples were subsequently extracted. All in all, a total of four days worth of water and sediment samples were obtained.
Many of the collected samples contain living organisms, which were due to be cultured under laboratory conditions and investigated. The researchers are hoping to rule out the possibility that they had introduced the microorganisms during the drilling procedure.
Speaking to the National Geographic, Chief Biologist of the Whillans Ice Stream Subglacial Access Research Drilling, John Priscu, claims recent laboratory work hints at the presence of ancient, subglacial microorganisms, thriving within the gloomy, cold environment of Lake Whillans. Priscu claims that DNA sequencing techniques are yet to be conducted; his team also plans to conduct a series of experiments to determine how this ancient life managed to endure the harsh conditions.
Meanwhile, a British and Russian teams were also deployed to investigate the mysterious underground network, stretching across the Antarctica. The British team encountered equipment failure, when drilling into Lake Ellsworth, and were forced to prematurely end their research efforts, whilst Russian researchers are currently attempting to analyze samples from Lake Vostok, obtained earlier this year.
Future Implications
The team that explored Lake Hodgson indicate that their work proves the existence of ancient life beneath the subglacial lakes of the Antarctica. The scientists call for future work to be conducted into this novel area of research, the results of which could inform scientists on how to proceed when accessing deeper subglacial regions. They suggest additional physiological and biochemical investigation, following acquisition of culture samples.
The group state they were able to generate 20 cultures, highlighting the viability of at least a small fraction of Lake Hodgson’s living organisms. On this basis, they explain that the bacteria belong to “… distinct ecosystems with huge potential.”
The results could also highlight the potential for bacteria to exist on the icy moons of Jupiter or Saturn, as well as other celestial bodies with similar conditions to the low temperature, dark environments of these subglacial lakes. But, whatever the implications of these studies, it seems that ancient life has finally been uncovered on our planet, stirring below in the icy lakes of the Antarctic.
Scientists discover never-before-seen organic molecules in Sutter’s Mill meteorite
According to a September 10 news release from Arizona State University (ASU), scientists have made a remarkable discovery regarding the possible catalog of molecules available to the early Earth.
Led by ASU research professor Sandra Pizzarello, a team of scientists discovered that the Sutter’s Mill meteorite – which exploded in a giant fireball last year – yields organic molecules not previously seen in any meteorites. The discovery suggests that there is a much greater availability of extraterrestrial organic molecules than previously believed possible.
The findings appear this week in the Proceedings of the National Academy of Sciences, in an article entitled, “Processing of meteoritic organic materials as a possible analog of early molecular evolution in planetary environments.”
Sutter’s Mill is also the site which drove the onset of the 1849 California Gold Rush. As the meteorite was detected by Doppler weather radar, the remains were quickly recovered, so that scientists could study the meteorite with little exposure to the elements.
“The analyses of meteorites never cease to surprise you… and make you wonder,” said Pizzarello. ”This is a meteorite whose organics had been found altered by heat and of little appeal for bio- or prebiotic chemistry, yet, the very Solar System processes that lead to its alteration seem also to have brought about novel and complex molecules of definite prebiotic interest such as polyethers.”
Pizzarello and her team heat-treated meteorite fragments, and then detected the compounds released using gas chromatography-mass spectrometry. The hydrothermal conditions of the experiments mimicked early Earth conditions, and released a complex mix of oxygen-rich compounds. The scientists believe that this is the result of oxidative processes in the meteorite.
The discovery adds to the catalog of organic compounds produced in extraterrestrial environments, and provides evidence to the discussion of whether or not their arrival to the early Earth by comets and meteorites aided the molecular evolution that heralded the origins of life. –Sciencerecorded via Google News
