Science news editors are usually leery of papers published in the Proceedings of the National Academy of Sciences (PNAS). Although the journal seems to carry weight among the scientific community — and is frequently cited by other journals — it’s known for having a fairly lax peer-review process.

A potential PNAS paper must first be sponsored by one of the 2,000-odd elite members of the Academy, who is then responsible for sending it out to anonymous reviewers and collecting their responses. Apparently, some of the members have their own ways of doing this.

Academy member Lynn Margulis, a biologist from the University of Massachusetts, Amherst, reportedly disregarded a bunch of negative reviews for a paper she sponsored, which proposed a theory that she agrees with: that caterpillars become butterflies because, many eons ago, butterflies accidentally mated with velvet worms. The paper was published online in PNAS after Margulis finally gathered some positive reviews of it. Now (after she spoke about her selection bias with a Scientific American reporter) the journal’s editor-in-chief is saying the paper will never make it into print, and moreover, that two new papers sponsored by Margulis will also be held up.

Dr. Margulis defended herself in an email to Nature News:

“We will win one way or another because this is science,” Margulis wrote in an e-mail. “I followed all the rules and submitted more reviews than I needed, and if they definitively reject these papers I will make it very clear to the reading public (because they make it clear in their anonymous letters) that, as usual, they don’t like my ideas.”

It’s not clear to me if ethics were breached in this particular case. But it’s safe to say that I’ll continue to take claims made in PNAS papers with a healthy dose of skepticism.