In all, the astronomic hype was met with earth-shaking backlash in 2010 and 2011. In 2012, Science published two studies refuting the claim that GFAJ-1 incorporates arsenic atoms into its DNA. Outside scientists concluded that it is an arsenic-tolerant extremophile, but not a profoundly different life form.

Retraction

But now, in 2025, it is once again spurring controversy; on Thursday, Science announced that it is retracting the study.

Some critics, such as Redfield, cheered the move. Others questioned the timing, noting that 15 years had passed, but only a few months had gone by since The New York Times published a profile of Wolfe-Simon, who is now returning to science after being perceived as a pariah. Wolfe-Simon and most of her co-authors, meanwhile, continue to defend the original paper and protest the retraction.

In a blog post on Thursday, Science’s executive editor, Valda Vinson, and Editor-in-Chief Holden Thorp explained the retraction by saying that Science’s criteria for issuing a retraction have evolved since 2010. At the time, it was reserved for claims of misconduct or fraud but now can include serious flaws. Specifically, Vinson and Thorp referenced the criticism that the bacterium’s genetic material was not properly purified of background arsenic before it was analyzed. While emphasizing that there has been no suggestion of fraud or misconduct on the part of the authors, they wrote that “Science believes that the key conclusion of the paper is based on flawed data,” and it should therefore be retracted.

Jonathan Eisen, an evolutionary biologist at the University of California, Davis, criticized the move. Speaking with Science’s news team, which is independent from the journal’s research-publishing arm, Eisen said that despite being a critic of the 2010 paper, he thought the discussion of controversial studies should play out in the scientific literature and not rely on subjective decisions by editors.

In an eLetter attached to the retraction notice, the authors dispute the retraction, too, saying, “While our work could have been written and discussed more carefully, we stand by the data as reported. These data were peer-reviewed, openly debated in the literature, and stimulated productive research.”

One of the co-authors, Ariel Anbar, a geochemist at Arizona State University, told Nature that the study had no mistakes but that the data could be interpreted in different ways. “You don’t retract because of a dispute about data interpretation,” he said. If that were the case, “you’d have to retract half the literature.”