NASA Life Discovery: New Bacteria Makes DNA With Arsenic

source: National Geographic - Daily News

A scanning electron micrograph of the arsenic-based bacteria. Image courtesy Science/AAAS

A new species of bacteria found in California's arsenic-rich Mono Lake, (a volcanic valley southeast of Yosemite National Park), is the first-known life-form that uses arsenic to make its DNA and proteins.

While arsenic is toxic to most known organisms, the bacteria not only tolerates high concentrations of the element, it actually incorporates it into its cells.

Dubbed the GFAJ-1 strain, the bacteria can substitute arsenic for phosphorus, one of the six main "building blocks" for most known life. The other key ingredients for life are carbon, hydrogen, oxygen, nitrogen, and sulfur.

While Earth remains the only planet known to contain life, the discovery of these extremophiles holds implications for the search for life elsewhere in the universe, since it shows that organisms can exist in chemical environments biologists once wouldn't have imagined.

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On a funny note,

Arsenic-Based Life

(xkcd)

Discoveries: Sea Microbes

Huge numbers of newly-discovered microscopic sea species are coming to light.

All of the knowledge collected in the last 10 years by the Census of Marine Life will be released in October of this year.

The first known vegetarian spider

In the tropical habitats of southeastern Mexico and northwestern Costa Rica, where a certain species of ant protect acacia trees in return for shelter and food, their mutualistic relationship is exploited by an unexpected source.

A study published this Monday in the journal Current Biology reveals the first known vegetarian spider amongst an approximate 40,000 spider species. The Bagheera kiplingi, named in the 1800s after the panther character in Kipling's The Jungle Book, has managed a way to leap from thorn to thorn to eat the nutrient-rich buds the acacia trees produce to reward their mutualistic protective ants.

The spider uses its superb strategies to hunt on the plant while avoiding the highly aggressive ants.

Apparently, though the spiders occasionally snack on ant larvae, the bulk of their diet is the plant itself.

Notes:

Although I was unable to find the full article on the journal itself, I read the info related to it on the National Geographic webpage. The photograph is from the same source and was taken by Robert L. Curry.