The Extinction Event and Life in the Post-Apocalyptic Greenhouse :: Exploratory Essays Research Papers

The Extinction Event and Life in the Post-Apocalyptic Greenhouse The biggest mass extinction of the past 600 million years (My), the end-Permian event (251 My ago), witnessed the loss of as much as 95% of all species on Earth. Key questions for biologists concern what combination of environmental changes could possibly have had such a devastating effect, the scale and pattern of species loss, and the nature of the recovery. New studies on dating the event, contemporary volcanic activity, and the anatomy of the environmental crisis have changed our perspectives dramatically in the past five years. Evidence on causation is equivocal, with support for either an asteroid impact or mass volcanism, but the latter seems most probable. The rest of this article spends time speculating through the advances in technology and the reanalyzation of old evidence to determine various cataclysmic events that happened millions of years ago. There are many sections in this article that discuss the methods used to determine the closet possible dates and the sequence in which they follow. There are also sections in this article which discuss methods used for the evidence of impact, eruption and how reading the environmental changes can help paleontologists determine conclusions and narrow the perspectives of paleontologists (scientists) and popular culture as a whole. However, there are still many factors in the evidence collecting process that make it difficult to determine the actual events, let alone the sequence of them. For instance, at the end of the Permian, giant volcanic eruptions occurred in Siberia, spewing out some 2 million km3 of basalt lava, and covering 1.6 million km2 of eastern Russia to a depth of 400-3000mteres, equivalent to the area of the European Community. Consequently, with increasingly precise dating, the Siberian â€Å"Trap† (areas which are composed of basalt, a dark-colored igneous rock which is generally not erupted explosively from classic conical volcanoes, but usually emerges more slowly from the long fissures in the ground) have switched from having only a minor role in the Permian crisis to being the most probable cause of the whole catastrophe. Some scientists have even suggested recently that the massive flood basalts were actually themselves caused by a giant extraterrestrial impact, which tore deep into the continental crust of that part of present-day Siberia. So this is yet another example the evolutionary and