TY - JOUR A1 - Stearns, S.C. T1 - The evolutionary significance of phenotypic plasticity: phenotypic sources of variation among organisms can be described by developmental switches and reaction norms Y1 - 1989 DO - 10.2307/1311135 JF - BioScience VL - 39 IS - 7 SP - 436 EP - -445 ER -