The Arsenic DNA Bacteria that might not be!


So, earlier last week, NASA comes out with an announcement saying that it will have a press conference on the 2nd of December to announce a major development that has implications to astrobiology.

A day after NASA announcement, Gizmodo published a highly speculative article that predicted that NASA is going to announce that they have found life in one of Saturn’s moons. Then there was just a flood gate of article, some of them with completely bizarre and unfounded speculations and rumors about the discovery.

On December 2, 2 PM, NASA announces the finding (at the same time the article was made available in Science Magazine titled A Bacterium That Can Grow by Using Arsenic Instead of Phosphorus. The authors claimed in the paper and asserted in the press conference that they have shown that these bacteria can not only tolerate Arsenic but incorporate it into their DNA structure replacing Phosphorous.

This followed another flood of reports and blog posts. There was great excitement about the news, especially because it, if correct, would mean that the life can support a much wider range of conditions than we thought. It also will suggest that the main ingredients if life as we know are not that fixed after all.

First thing to come out of it was that, it was certainly over hyped by NASA by clearly hinting it is something more than what it is. Yes, finding a life form that can substitute Arsenate instead of Phosphate is an incredible finding. But, we know life on earth is very resilient and innovative. It would certainly don’t mean that we are closer to finding exobiological entities.

Along with this, there came a series of posts by scientists questioning the veracity of the methods used by the NASA scientists (Felisa Wolfe-Simon et al). Among the many I read about this subject there are two that stand out in its clarity of presentation and scientific rigor (no, that is not to make any claims about its correctness).

The article by Alex Bradley looks at the problem from a chemist’s perspective and brings up a few very serious process and interpretation issues. He correctly points out that there were due diligence that the NASA scientists did not perform.

An even more detailed criticism by Rosie Redfield can be read here. She goes more into the methodology and points out many potential pitfalls in them.

All this reminded me of the famous Carl Sagan adage “Extraordinary claims require extraordinary evidence”.

Another point this brings to light is the methodology of science and the immediacy and openness with which it is happening. Answering requests for comment, one of the authors of the article said that the discussion should happen in peer reviewed journals, not in the blogosphere. That is a bit odd though, considering that they themselves made an effort to make this very public.

Irrespective of how this particular finding turns out, science will go on. I have noted this earlier, the usually hidden away dynamics of the process of scientific enquiry is now spilling over for every one to see. It is beautiful, exciting. Now, if only the media learn to stop seeing everything in black and white.

 

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: