Introduction 2008 2006 2008 2000 2004 2005 2005 2006 E 2003 Phaseolus lunatus 2006 2007 Z 2006 Materials and Methods −1 −1 Z E E Z Z E 2006 2006 Results and Discussion Z 2006 F 77,10 P Z P 1 Z E E Z Z 2006 Fig. 1 A Z B E C E D E Z F Z G H E I K LC lines within boxes Different letters appearing above boxes P A F G K  2003 Z Z Z 2004 2005 2005 Z E E E E Z E Z E Z E 1 2007 2001 E 2006 E 1 How can signals evolve that apparently lack chemical specificity? The answer might be simply that plants seldom are exposed to GLVs or chemically related compounds that are not released from attacked plants. In evolutionary terms, the probability of this situation was probably too low to cause any selection towards a more specific signal perception.