ELREDGE N. - Reinventing Darwin. New York, John Wiley & Sons, 1995 ELREDGE N and CRACRAFT J. (eds) - Phylogenetic patterns and the evolutionary process. New York, Columbia Univerity Press, 1982 HEENIG W. - Phylogenetic systematics. Chicago, University of Illinois Press, 1966 McKINNEY M. L. (ed) - Heterochrony in evolution: a multidisciplinary approach. New York, Plenum Press, 1988 McKINNEY M.L. and McNAMARA K.J. - Heterochrony evolution of ontogen. New York, Plenum Press, 1991 KIMURA M. - The neutral theory of molecular evolution. Cambridge, Cambridge Univeristy Press, 1983 MAYR E. - One long argument: Darwin and the genesis of modern evolutionary thought. Cambridge, Havard University Press, 1991