Why is it dangerous to lose a species ?

Human beings are dependent on the biological components of the environment for various reasons. The most important of which is perhaps Food and although we might not feed directly on endangered plant and animal species, other organisms might be dependent on them for their livelihood and a large proportion of the wild progenitors of our food plants are nowadays endangered. Furthermore, each species plays an important role in the Ecological Cycle and its absence will affect the cycle as a whole. Two other major uses of plants (and sometimes animals) are Medicine and Industry. And since we do not live on food alone, it is appropriate to consider Ornamental Plants which beautify our gardens and enliven our homes with their green and flowers.

Chelonia mydas
the green trutle is now endangered in Egypt & used to live in the Red & Mediterranean Seas.