I recently commented on NASA’s paper regarding bacteria that can successfully incorporate arsenic into their biochemistry. Well, another blogger who has more expertise related to the paper has posted a very critical analysis. It is worth reading.
Essentially, the blogger believes that it is very possible the bacteria that lived in the arsenic-only cultures might have been scavenging phosphorous from others in the population that had died. As a result, the blogger is skeptical that arsenic was incorporated into the bacteria’s biochemistry to any meaningful extent.
The blogger is especially critical of the analysis claiming to have found arsenic incorporated into the bacteria’s DNA. He thinks the DNA-related data can be explained by contamination:
If this data was [sic] presented by a PhD student at their committee meeting, I’d send them back to the bench to do more cleanup and controls.
Based on the comments, it seems the blogger is sending a modified version of the post to Science as a letter to the editor. It will be interesting to see how the NASA group responds.