The roots of the problem

In purely ecological terms, what provokes the extinction of a species is the destruction of its habitat and the impossibility to find another one. When the environments change, many of the physical and chemical characteristics change with excessive speed compared to the time for biological adaptation: the organisms that live there die, unless they are able to migrate.
The five great biological extinctions of the past were provoked by ecological dynamics that did not depend on human impact (also because the appearance of Homo sapiens was remarkably later) that had these characteristics . For example, biologists believe that the two extinctions of the late Ordovocian era and the late Devonian era were the result of a violent change in the conditions of the climate; while the interpretation of the extinction of the late Cretaceous era was due to the effect of the collision of our planet with one or perhaps two large meteorites. It is known that these collisions had such repercussions on the global biological balance, that they led to the disappearance of the dinosaurs and many other organisms.
At present, however, the planet is experiencing a condition that had never occurred in the past, at least in the amount that we can see today: the rapid disapperance of species due in particular to human beings. Scientists believe that the speed of erosion of biodiversity today is similar to what characterized the great extinction events of the past, with the sole difference that this time the cause is to be found in the anthropic activities.
Diversely from what has been stated about the five historical extinctions, then in this case we must deal with a process that, besides having obvious ecological implications, it also has an ethical and cultural value that must not be neglected. In fact we wonder if it is right that man should dilapidate the biological richness of the planet, without thinking of his responsibilities with regard to the survival of nature and of the future generations of human beings. Many authors believe that the “ecology crisis” that we are going through may have negative consequences on the quality of our life in a very short time, and it is obvious that this worry leads to reflections and discussions that are not only scientific.

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