EVOLUZIONE: UNA TEORIA IN CRISI DI CRESCITA
The history of Darwinism, far from being a grandiose march from early doubts to the general acceptance, is complex and devious. Right from the beginning the early followers of Darwin (Weismann, de Vries, Haeckel…) have substantially modified in different points the original Darwinian model of evolution. In the twenties and thirties of the twentieth Century a formidable work of unification of many different research traditions (population genetics, naturalistic research, laboratory genetics…) has built the “Modern Synthesis”, that is the common actual conception of the evolutionary theory, based on minor, random, genetic changes and the slow and steady action of natural selection. However in the following years many new data and research programs – from the Neutral Theory of molecular evolution to symbiosis, from the Evo-Devo to the Niche Construction and many others, have undermined the stability of the Modern Synthesis so as some authors are now suggesting the necessity of an Extended Synthesis. However, at the moment, a hard core around which to build a new synthesis is not in sight.