Exobiology and Evolutionary Biology

Diving Through A Microbial Landscape

Scientist Dale Andersen prepares to dive in Lake Untersee in Queen Maud Land in Antarctica. Photo: Dale Andersen
The ice-covered lakes of Antarctica’s McMurdo Dry Valleys have long been of interest to astrobiologists. These remote and extreme environments harbor unique microbial ecosystems that could provide clues about how life might survive on other worlds – such as Jupiter’s icy moon, Europa. Recently, a team of scientists funded by the NASA Exobiology Program began exploring the unique habitat of the ice-crusted Lake Joyce.

Lake Joyce is of special interest, because it’s waters harbor carbonate structures known as microbialites. These unique structures are formed with layers of cyanobacteria. The research team is interested in how these organisms...

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Source: [OnOrbit]

October 29, 2009 / Posted by: Aaron Gronstal

NASA-Supported Researcher Shares in Nobel Prize

Jack W. Szostak, a Howard Hughes Medical Institute investigator at Massachusetts General Hospital and Harvard Medical School, is among a group of three researchers who have been awarded the 2009 Nobel Prize in Physiology or Medicine. Szostak, who shares this year’s prestigious scientific award with Elizabeth H. Blackburn of the University of California, San Francisco, and Carol W. Greider of the Johns Hopkins School of Medicine, is also a principal investigator with NASA’s Exobiology and Evolutionary Biology Program and a member of the NASA Astrobiology Institute. The award was announced by the Royal Swedish Academy of Sciences on...

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Source: [HHMI]

October 5, 2009 / Posted by: Aaron Gronstal

Dinosaur-Killer was Soft on Algae

A view of the sea cliff at Stevns Klint, Denmark. Credit: R. Summons
The asteroid impact that many researchers claim was the cause of the dinosaur die-off was bad news for marine life at the time as well. But new research funded by NASA shows that microalgae – one of the primary producers in the ocean – bounced back from the global extinction in about 100 years or less.

Source: [astrobio.net]

October 2, 2009 / Written by: Michael Schirber

Mars Reconnaissance Orbiter Sees Ice Exposed by Meteor Impact

NASA’s Mars Reconnaissance Orbiter has revealed frozen water hiding just below the surface of mid-latitude Mars. The spacecraft’s observations were obtained from orbit after meteorites excavated fresh craters on the Red Planet.

Scientists controlling instruments on the orbiter found bright ice exposed at five Martian sites with new craters that range in depth from approximately half a meter to 2.5 meters (1.5 feet to 8 feet). The craters did not exist in earlier images of the same sites. Some of the craters show a thin layer of bright ice atop darker underlying material. The bright patches darkened...

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Source: [NASA Press Release]

September 24, 2009 / Posted by: Daniella Scalice

Comets May Give Life a Hand

A comet hitting Earth would seem to bring only death and destruction, but one group is studying how such an impact could promote certain necessary chemical steps in the origin of life. The researchers are focusing on how comet collisions might have influenced the molecular orientation, or handedness, of our planet’s biology.

Source: [astrobio.net]

September 24, 2009 / Written by: Michael Schirber

Greening the Earth

Late Precambrian carbonate outcropping is visable at the south end of Death Valley, California. Carbon isotopes in these layers bear evidence of the first extensive greening of the Earth
One of the most dramatic and seemingly inexplicable events in the history of Earth’s biosphere occurred roughly 540 million years ago when multi-cellular life exploded all over the planet. This large-scale diversification of life is known as the ‘Cambrian explosion’ and lead to the variety of organisms we see on Earth today. Scientists have often attributed the Cambrian explosion to significant geologic or climatic changes on our planet, but new NASA-sponsored research may have a better explanation.

Rather than catastrophic disruptions in Earth’s climate, a new study indicates that the Cambrian explosion may have been caused by more...

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Source: [Nature]

August 26, 2009 / Written by: Aaron Gronstal

Eating by Osmosis

New research shows that the oldest complex lifeforms on Earth likely fed by osmosis. Modular organisms lived in the nutrient-rich oceans of the Ediacaran period more than 540 million years ago. These organisms were unlike any other on Earth, and because of this they are not well understood. Now, scientists may have determined how these unique creatures were able to feed. A new study shows that they likely absorbed nutrients through their outer membrane – using a method known as ‘osmosis’. The study provides new insight into the evolution of life on Earth.

Source: [astrobio.net]

August 22, 2009 / Posted by: Aaron Gronstal