Biodiversity is the connection among all living things on the planet. At best, scientists have identified only a small percentage of the species on the planet -- less than 1.5 million. However, experts estimate that there are anywhere from two to 100 million species on the planet, and we're losing species at the rate of up to 0.1 percent (of all species) per year. This is 10,000 times the speed at which natural selection would eliminate species without human intervention [source: Equator Initiative].
As species disappear, the changes in the environment become deeper and more serious. Biodiversity is affected. The disappearance of a single species changes the dynamics of the surroundings for all other species, and these changes can also affect humanity at a much deeper level. Many of the synthetic drugs we use today are of natural origin, and if species disappear, so can possible cures.
So what's threatening biodiversity? A lot of things -- and some of them might just surprise you.
Let's take a look at 10 of the biggest threats to Earth's biodiversity.