One of the many year-end lists Outliers saw recently takes an interesting look back at the past 12 months in science news—naming the top five retractions made by science journals in 2011.

A 2009 paper published in the Proceedings of the National Academy of Sciences claimed that the ancestors of modern butterflies may have fertilized their eggs with the sperm of velvet worms—a paper that Live Science columnist Christopher Wanjek said “got a few laughs among evolutionary scientists” at the time.

That paper wasn’t retracted, but a follow-up article, which published in Symbiosis in 2011, was.

According to Wanjek, some of the other notable published-and-then-retracted papers of the year include an article published by Indian researchers that found antibiotics could serve as an alternative to an appendectomy and the claim that chronic fatigue syndrome is caused by the xenotropic murine leukemia virus-related virus.

Then there’s the one published in Science by a Dutch social psychologist claiming to have found that trash and graffiti in cities can foster changes in the brain leading to crime, hatred and discrimination. Interesting … until it was revealed the senior author seems to have made up most of the data in that and more than two dozen other papers, and has since been suspended from Tilburg University in the Netherlands.

And we promise we won’t have to retract that.