The Eastern Arc Mountains are the oldest mountains in East Africa. Magnificent rainforests, nurtured by winds from the Indian Ocean, thrived in Tanzania for more than 20 million years. Today, the forests have been reduced by more than 70% and are fragmented across the 13 free standing mountain ranges. As the climate began to change, elephants spread across the continent and as the human population grew with its steady logging, fires and farmland conversion, the forest was pushed back resulting in geographical isolation and discrepant evolution. Each range now has species of plants and animals not found across the dry savanna in the next forest island. Scientists call the Arc the "Galapagos of Africa" due to its high endemism.