Department of Experimental Biology, University of Jaén, Jaén, Spain.|Department of Differential Equations and Numerical Analysis, University of Seville, Seville, Spain.|Department of Differential Equations and Numerical Analysis, University of Seville, Seville, Spain.|Department of Applied Mathematic I, University of Seville, Seville, Spain.|Department of Philosophy, Logic and Philosophy of Science, University of Seville, Seville, Spain.