The human activities have conquered the biodiversity to worldwide scale, national and regional and continue . This is shown at vegetable and animal populations loss, in extinction and in the exhaustion of species and in the simplification of communities and ecosystems. There are two forms to evaluate the biodiversity's exhaustion: Investigation and the direct observation and the elaboration of theories what it can happen of on the base so that at present it is common knowledge.

An analysis reveals than 600 species have extinguished XVII from the beginning of the century. Close to the three fourth parts of these acknowledged extinctions have happened at islands, as a consequence of the human occupation; the causes have been the over-exploitation, the destruction of habitats and the impact caused by animals' introduction. The registered extinctions have raised very much from the beginning of the century XIX mediated of the XX. Nearby of 6,000 animal species are considered threatened of extinction because the number of individuals that they form are decreasing, because his habitats in consequence of over-exploitation are getting destroyed or because, simply, his distribution area has been limited very much. Observations of field have confirmed that there are a relation between the size of an area and the number of species that it contains. A generalization suggests what if a stain of habitat becomes smaller to the tenth part of his original surface, it's probable that you lose the half of species that you had. Numerous individuals, organizations and countries have worked on last decades to identify populations, species and habitats threatened to extinction or degradation and to turn these tendencies. The common goals are to try to obtain more efficaciously the natural world to mitigate the influence of the human activities and, at the same time, improving the options of development of the underprivileged towns. Many conservationists hope that history demonstrate than the year 1992 has constituted an inflection point. In June of that year was shown the signature of The Agreement on the Biological Diversity in the Conference of the United Nations about Environment and Develop, celebrated in Rio de Janeiro. The Agreement became effective to endings of 1993, and at the beginning of 1995 one hundred countries had signed it over; this means that they agree with his intentions and that they will make every effort to fulfill his dispositions.

We are in the 2007 and not yet we give importance to him, neither do we want to become aware of what we are doing to the earth, to our home, to our children, else the man is who the change make who will do it? It seems like the large developed countries are deviating their attention on not losing their cost-reducing or warlike power, but... and agreements, promises, the calls of alert? It seems like we hoped to lose our opportunity to change our destination, for later saying... if we would have... Or than beautiful it was, wasn't it?? And seeing showing an old photo to our grandchildren when the land even was a safe place.