Controversial 2010 Study on Arsenic-Based Life Retracted After 15 Years

The controversial claim of microbes that exhibit arsenic rather than phosphorus in their biochemistry has been retracted by the journal Science 15 years after it was first published — but while most in the research community are pleased by the decision, the retraction has angered the authors of the original study.

Arsenic, as we know from its use as a poison, is a toxic substance. Thus, life as we know it of course would not include arsenic in its biochemistry. Yet, because the search for alien life is, by its very definition, a search for life as we don't know it, astrobiologists like to consider the possibility of organisms that have a different biochemistry to the one we're familiar with.

This, in fact, led to NASA, holding a press conference in 2010 that declared the supposed discovery of arsenic-based microbial life in Mono Lake, which is a heavily salt-rich body of water in California.

Consider that all life as we know it, including human life, exclusively uses six key elements in its biochemistry: carbon, hydrogen, nitrogen, phosphorus, oxygen and sulfur.

Astronomical observations suggest phosphorus might not be evenly distributed across the Milky Way galaxy. It has been posited that life in those phosphorus-depleted regions of space might survive by substituting phosphorus with another element, such as arsenic. It was this possibility that prompted a team to search for possible arsenic-based life in Mono Lake.

When the discovery team revealed they had found a bacterium known as GFAJ-1 present in supposedly phosphorus-free samples from Mono Lake, it was hailed as a revolutionary development in astrobiology. However, subsequent research raised doubts about the findings, leading to the retraction of the paper.

Now, 15 years later, Science has retracted the paper based on flawed data. The authors of the original study disagree with this decision, stating that they stand by the data as reported.

Lessons can be learned from this incident about presenting controversial results and receiving scientific criticism. It highlights the complexities of when and how papers should be retracted in the scientific community.

According to the source: Space.