In the Western United States there is a tree called the "Bristlecone Pine." Growing in the mountain regions, sometimes as high as two or more miles above sea level, these evergreens may live for thousands of years. They are is among the longest-lived life forms on Earth. The older specimens often have only one thin layer of bark on their trunks. Considering the habitat of these trees, such as rocky areas where the soil is poor and precipitation is…