Extracts of the rosy periwinkle, catharus roseus, have provided medicine with vincristine and vinblastine, drugs now available for treating cancer. the ability to find this species of plant and discover these drugs is a strong argument for

The answer is preserving biodiversity. It can be well-defined as the biological changeability among all living plants and animals of the earth as an outcome of the evolution procedures and contains of three levels of biological diversity which are genetic diversity, species diversity and ecosystem diversity.