The retracted study concerned GFAJ-1, a bacterium collected in Mono Lake's arsenic-filled waters by Felisa Wolfe-Simon, then a researcher at the NASA Astrobiology Institute and the U.S. Geological Survey. Citing experiments on the microbe, she and colleagues suggested it used the normally toxic element in place of phosphorus to make DNA and proteins. A NASA release claimed the discovery "broadens our thinking about the possibility of life on other planets, and begs a rewrite of biology textbooks." But the work swiftly attracted challenges by other researchers, and attempts to replicate it failed...After controversy sparked by the paper's online publication delayed...