What are the reasons for the diversity of species in nature and the possible consequences of the loss of such diversity?

There is a very wide variety of species on our planet. This is due to the evolutionary process. In the course of evolution, new adaptations and mutations arose in animals. New species gradually appeared. But even in our time, there are not so many species. Now only 1% of the species that existed on our planet live. Moreover, scientists have calculated that 3 species disappear every hour. These are huge numbers, but they cannot influence the overall picture. The species, which are not quite necessary and small in number, are disappearing. If large and important species disappear, this can lead to the death of other species.