Uninhabited by humans until 2,000 years ago, the island's isolated evolutionary path gave rise to unique groups of plants and animals, including more than 30 species of lemur, two-thirds of the world's chameleons, 1,000 species of orchids, an array of baobabs, and the xeric vegetation of the desert. More than 80 percent of Madagascar's flora and fauna are endemic, making the island's contribution to the world's biodiversity immeasurable, and its conservation a global priority. The SIT Study Center is located in Fort Daupin (Tolagnaro), surrounded on three sides with spectacular Indian Ocean beaches.