Subscribe free to our newsletters via your
. 24/7 Space News .

Is a new form of life really so alien?
by Staff Writers
La Jolla CA (SPX) May 09, 2012

Joyce argues, "A life form that arises directly from bit-free chemistry would be considered 'new' from the outset, while one that derives from a biological cell would have a long way to go before reaching the threshold."

The idea of discovering a new form of life has not only excited astronomers and astrobiologists for decades, but also the wider public. The notion that we are the only example of a successful life form in the galaxy has, for many, seemed like an unlikely statistic, as we discover more and more habitable planetary bodies and hear yet more evidence of life's ability to survive in extreme conditions.

A new essay, published May 8 in the online, open-access journal PLoS Biology, examines what really constitutes 'life' and the probability of discovering new life forms. Accompanying the article is an interview with the author in the latest edition of the PLoS Biology Podcast.

Professor Gerald Joyce, from The Scripps Research Institute in La Jolla, California, discusses in the essay the basic requirements for a life form to exist. He says, "Life self-reproduces, transmits heritable information to its progeny, and undergoes Darwinian evolution based on natural selection."

He refers to this heritable information as 'bits' (for life as we know it, this includes the four bases of DNA), and explains that although Darwinian evolution results in new combinations of these bits, this does not define a new or alien form of life.

Indeed, to date no truly new life form has been discovered-either in extreme environments on Earth or on other planets-that contains new bits, despite evidence suggesting life on meteorites recovered in Antarctica, or on any of the so-called 'habitable' planets discovered in our galaxy.

How could a truly new life form arise? Joyce explains that an organism could either arise directly through chemistry, or spin off from existing biology. For the former, a life form would self-organize "into a bit-generating system."

It's thought that this is how life originated on Earth; from a primordial soup of chemicals in an aqueous environment that generated self-replicating molecules, which then mutated and evolved.

Joyce argues, "A life form that arises directly from bit-free chemistry would be considered 'new' from the outset, while one that derives from a biological cell would have a long way to go before reaching the threshold."

It is in these differences between chemical or biological initiation-that is to say, whether the life form has developed from an existing life or seemingly independently-that confusion and misinformation occurs surrounding the probability of a new life being discovered or created. Given that we only know of one life form-our own-we can't meaningfully estimate the probability of new life arising, either on Earth or elsewhere.

"I think humans are lonely and long for another form of life in the universe," says Joyce, "preferably one that is intelligent and benevolent. But wishing upon a star does not make it so.

"We must either discover alternative life or construct it in the laboratory. Someday it may be discovered by a Columbus who travels to a distant world or, more likely in my opinion, invented by a Geppetto who toils at the workbench."

In the accompanying PLoS Biology Podcast, Joyce discusses in more depth the ability of scientists to discover the origin of novel life forms, and whether the emerging field of synthetic biology can actually lead to new forms of life. Joyce GF (2012) Bit by Bit: The Darwinian Basis of Life. PLoS Biol 10(5): e1001323. doi:10.1371/journal.pbio.1001323 A podcast is available here


Related Links
Public Library of Science
Life Beyond Earth
Lands Beyond Beyond - extra solar planets - news and science

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

Microbes Go Rafting on Floating Volcanic Rocks
Moffett Field CA (SPX) May 02, 2012
Volcanoes bring death and destruction, but out of the ashes life soon finds fertile ground. A unique experiment is sifting through floating debris from an ongoing volcanic event to see how microbes move in. The results may help in assessing a recent hypothesis that the first life forms may have found fertile ground in the pores of volcanic rocks. James Elser of Arizona State University was ... read more

Perigee "Super Moon" On May 5-6

India's second moon mission Chandrayaan-2 to wait

European Google Lunar X Prize Teams Call For Science Payloads

Russia to Send Manned Mission to Moon by 2030

Russia could join U.S. in Mars mission

Antarctic stay to mimic Mars mission

Mars Rover Opportunity Hits Paydirt At Endeavour

Ancient Volcanic Blast Provides More Evidence of Water on Early Mars

Boeing Completes Full Landing Test of Crew Space Transportation Spacecraft

How will the US biotechnology industry benefit from new patent laws?

Space -- the next frontier for Hillary Clinton?

Company to Create 'Gas Stations' in Space

China's Lunar Docking

Shenzhou-9 may take female astronaut to space

China to launch 100 satellites during 2011-15

Three for Tiangong

Dancing Droplets Rock Out On Space Station

Space Station's Robotic Crew Member Designed to Look, Move and Work Like a Human

Expedition 30 Lands in Kazakhstan

Three astronauts to land from ISS Friday

SpaceX boss admits sleep elusive before ISS launch

Air Force launches 2nd advanced satellite

A trio of Ariane 5 launchers are now at the Spaceport

United Launch Alliance Urges IAM Members to Vote in Favor of New Contract

NASA's Spitzer Sees the Light of Alien 'Super Earth'

Looking for Earths by looking for Jupiters

Some giant planets in other systems most likely to be alone

Four white dwarf stars caught in the act of consuming 'earth-like' exoplanets

Life-size, 3D hologram-like telepods may revolutionize videoconferencing

Fewer toxic toys and textiles in EU stores

Colors burst into contemporary architecture

Flying 3D eye-bots

The content herein, unless otherwise known to be public domain, are Copyright 1995-2014 - Space Media Network. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA Portal Reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. Advertising does not imply endorsement,agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement