Journal Entry Eight(Chapter 8)-Ziomara Aguilar

.Global warming does not only threaten animals in cold climate but also animals in the tropics. In Peru, Kolbert meets with a scientist named Miles Silman. Silman is a professor who is a forest ecologist and studies tropical ecosystems in South America. In Peru, there is a large diversity of tree and animal species. One theory that suggests such diversity in the tropics is that "the evolutionary clock ticks faster." Animals reproduce faster leading to more genetic mutations that lead to more varieties of species. Another theory reasons that there is more diversity in tropical climates because they have a low-temperature fluctuation, therefore having mixed zones(tree tops, tree bases, etc). Each zone can have different lifeforms with different thermal tolerances. A third theory suggests that tropical ecosystems are diverse because they are older and have been able to become more diverse over time.
Silman keeps a record of the diversity of life at 17 different "tree plots". Him and his team record the average diameter of a tree, different life forms and other information of each tree plot. Silam has found that on average, the increased temperature of Peruvian forests has driven plants and animals higher up. Every species has evolved in some way to cope with the changes in temperature.
Scientists predict that during the next century, average world temperatures will increase considerably at a very fast rate. This poses a threat to life on earth as it is not clear which species will migrate north quickly enough to survive.