Thursday, December 02, 2010

NASA's Felisa Wolfe-Simon found life and DNA with As replacing P

...although some people hoped we would be shown aliens :-)...

Update: Dr Rosie Redfield wrote a very meaningful criticism that has turned me into a "mostly skeptic" concerning the claim that the arsenic got incorporated into the biological molecules. See also Dr Alex Bradley.

At any rate, NASA will hold a press conference at 8 p.m. Prague Winter Time (11 a.m. Pacific Standard Time) where panelists will discuss a finding that will "impact the search for evidence of extra-terrestrial life". ;-)

It turned out to be GFAJ-1, a bacterium in the Mono lake that incorporates arsenic instead of phosphorus into its body, including the DNA. The rest of the text became a bit obsolete after the press conference.

Fox rumors say that NASA will announce the discovery of biological activity - photosynthesis, in particular - on Saturn's moon Titan. It sounds simple enough and if the rumor is right, I plan to analyze the findings in detail.

One expert who will probably be present focuses on arsenic life forms so they may also announce some arsenic life on Earth. I would be comparably skeptical of this statement. Most likely, they will just produce a combination of both speculations: arsenic on Titan will be claimed to be evidence for photosynthesis on that moon. I would probably consider this argument complete bullshit because the overall amount of elements such as arsenic on Titan's surface doesn't depend on fancy processes such as life.

In general, I think it is a complete fallacy to use the existence of simple molecules as evidence for very complex molecules because statistically speaking, simpler molecules are always more likely to emerge than the complex ones, because of simpler processes, so the existence of complex molecules cannot possibly be a pre-condition for the existence of simpler ones. In this sense, I believe that to see the extraterrestrial organism itself is probably the only kind of reliable enough evidence that it exists.

Daily Mail seems much more specific about the rumors: they guess that NASA will simply announce new microbes in the Californian Mono lake that grow by eating arsenic and inserting it instead of phosphorus in their f*cking bodies. That's disgusting, indeed, but I don't think it makes the extraterrestrial life significantly more likely than e.g. the discovery of bats, dolphins, or anything else.

Having arsenic as an important part of your food content is perverse and seemingly opens new possibilities but you know, people need calcium, magnesium, and lots of other elements, too. And other people collect, but not eat, gold in their basements. That's great but it doesn't "explain" life. Playing with rare elements in the environment is what a pre-existing life form may enjoy to do. However, a lot of hardware and software has to exist for the complex molecules underlying these life forms to be created in the first place and to reproduce.


The main difficulty in the initial explosion of life is the task to create the required complexity of the molecules - not the shortage of energy or arsenic. The ability to do playful things with unusual parts of the environment is a consequence, not the cause, of the birth of life.

Here is the link to NASA TV. Be sure to pick the right channel.

Holy cow, I tuned this NASA TV to see some friendly old-fashioned science. However, 30 minutes before the press conference, what I got was a program with Judith Lean and James Hansen talking about global warming - a mission called "Glory".

Ten minutes later, they talked about Fermi verifying Lorentz symmetry. Their finding that the symmetry is not broken "surprised everyone". Well, it surely hasn't surprised me - or any genuine physicist, for that matter. ;-)

Not to make me too happy, there was also a program at 7:55 p.m. Prague Time promoting women and minorities in physics and astronomy.

By the way, I am reading lots of science news sources but I learned about this press conference from a Slovak pop-music radio station I listen to, Rádio Hej. ;-)

This station plays "the best Slovak music". One of the best things about the Slovak music on this radio station is that one half of it is Czech :-) - they're just not allowed to say it - and that includes Czech songs that are no longer played much on the Czech radio stations. By the way, similar Czech stations always say that they play the best "Czech and Slovak music", just to make you sure that the mutual love among two friendly but differently-sized nations often has its limitations.

1 comment:

  1. The normal comment section seems not to be up.
    This should give the anti-pollution/pro-biodiversity crowd something to think about. Normally adding arsenic to a lake would be thought of as pollution, but in this case adding arsenic could increase biodiversity. What if the Gulf oil spill increased the types of life found in the Gulf?