# Speech Perception –MotoricContributions versus the MotorTheory **Opening (not a real abstract):** eggs to be distinguished and that obligatorily shows up on the cuticle of the individual producing it. Reproductive workers are trapped because they necessarily show both queen’s and worker’s compounds. More generally, physiological or genetic constraints that prevent the uncoupling of traits involved in dual functions may suffice to stabilize reproductive cooperation in many biological systems [19]. References Sociobiology of Communication (Oxford: evolution of cooperation and altruism - a general framework and a classification of models. J. Evol. Biol. 19, 1365–1376. behavior evolve. Science 309, 93–93. 4. Bshary, R., and Bergmueller, R. (2008). Distinguishing four fundamental approaches to the evolution of helping. J. Evol. Biol. 21, 405–420.