While this is on the front page again, I wanted to make a mention of Joan Taylor, who discovered an aperiodic single tile, which she published with Joshua Socolar of Duke University. This is her bio blurb as it appears on their article in The Mathematical Intelligencer:
JOAN M. TAYLOR took up mathematics in 1991 at age 34 after being inspired by a magazine article on quasicrystals featuring Penrose’s rhombus tiling. She began but did not complete a degree, preferring to conduct her own research. Since then she has pursued tiling and related topics in abstract algebra and number theory including original work on constructible polygons. She likes to unwind with knitting and reading.