You’ve heard of the butterfly effect — the concept that a butterfly fluttering its wings a half a world away can set into motion a series of events that results weeks later in a hurricane off the coast of Florida. But the butterfly effect can also describe happier circumstances of cause and effect. I heard of one such example recently — about a young Sarasota woman, a 2009 graduate of Sarasota High, named Grier Ferguson. Click here to read the full story in my Dec. 20 Sense and the City column