[The challenge of science at the outset of the third millenium].

Compared to others species Homo sapiens is physically underprivileged as much by his relative weakness than by his lack of natural defense. Only his mental abilities allowed him to cope with the various dangers which threaten him and to rule over the biosphere that he managed to modified for his own benefit. The neolithic revolution which saw the generalization of agriculture and the breeding of animals offered a considerable quantities of resources which lead to a strong demographic growth. All this produced a successions of discoveries which improved his quality of life. Today after an era of quantitative growth the production of the agroalimentary sector enter a qualitative period in which the aim is note only to increase the production of the traditional resources but, by the alteration of the genetic heritage, to improve their properties.