The immensity of the living world now bears a name: biodiversity. To some it appears infinite, and it would not be wrong to consider it as such, since it is undergoing constant evolution. Darwin's work made it possible to understand the phylogenetic relationships between different species, and finally to weave the history of life over time.
Biodiversity isthe living fabric of our planet: it denotes the set of natural environments and life forms (plants, animals, fungi, bacteria and viruses) as well as all relationships between them.
This living wealth is threatened by human activity that modifies and accelerates its evolution: species extinction, changes in balance of ecosystems. The international community therefore aims to develop ways to best preserve this treasure. The IUCN (International Union for Conservation of Nature) developed a red list which identifies endangered species, in order to assess the risks to biodiversity. "Every species that disappears isone less to support others." Indeed, each organism, whether plant, animal, or microscopic, contributes in its own way to ecosystem stability. The multiplicity of interactions among these communities of living organisms has been responsible for generating this balance for millions of years of unparalleled creativity. The constant evolution of the genome has provided the means for life to adapt to extreme conditions, allowing the colonization of diverse environments. These habitats, along with the organisms inhabiting them, form countless ecosystems.
Biodiversity is therefore measured on different scales relative to genes, species, and ecosystem.
Man, by his lifestyle and practices, also affects these ecosystems by changing their environment. Crop diversity must not be neglected, in order to protect biodiversity from all angles. Humanitydepends on biodiversity for its own preservation, because the quality of our air, water and land depend on the health of the natural world.