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Permian mass extinctions research papers
Permian triassic mass extinction research paper
Mass extinction that ended the Permian and Cretaceous periods
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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 “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
In this paper Martin is arguing that late quaternary or near time extinctions where caused by human activity or as he calls it “overkill”. Martin recognizes that there have been many forces that have triggered extinctions in the planet on the past but disagrees with the idea that near time extinctions where caused by some commonly believed causes like climate change, disease or nutrient shortage. He argues that the arrival of humans to different continents, islands and the subsequent excessive hunting, the introduction of diseases and other competitors and predators was the cause of extinction of a great number of species “As our species spread to various continents we wiped out their large
“Sex, Drugs, Disasters, and the Extinction of Dinosaurs” is written by Stephen Jay Gould, professor of geology and zoology at Harvard. This essay is one of more than a hundred articles on evolution, zoology, and paleontology published by Gould in national magazines and journals. It tells about scientific proposals for the extinction of dinosaurs – a confusing but an exciting problem that humanity tries to solve. By analyzing and describing each of the claims for the reptiles’ demise – sex, drugs, and disasters – Gould differentiates bad science from good science and explains what makes some theories silly speculations, while the other, a testable hypothesis.
On May 22, 1915, an explosive eruption at Lassen Peak devastated nearby areas and rained volcanic ash farther 200 miles to the east! This explosion was the most powerful in a series of eruptions from 1914 through 1917. ...
Americas by 14,000 ago” (O’Brien 12), after large portions of North America encountered the last ice age, which
Robert F. Kennedy's chilling account of his experiences with his brother, President John F. Kennedy over thirteen days in October of 1962 give an idea to the reader of just how alarmingly close our country came to nuclear war. Kennedy sums up the Cuban Missile Crisis as "a confrontation between two atomic nations...which brought the world to the abyss of nuclear destruction and the end of mankind."1 The author's purpose for writing this memoir seems to be to give readers an idea of the danger confronted during the Cuban Missile Crisis and to reflect on the lessons we should learn from it as a country, and for future members of government.
Presently, many books and fairytales are converted movies and often, producers alters the original tales to grasp the attention of a large audience. However, some of these interpretations hide the primary interpretation. The original interpretations of the Disney classics Snow White and Sleeping Beauty are greatly reinvented from the original fairytales Sun, Moon, and Talia and Snow White and the Seven Dwarfs because of the brutal nature of the treatment women in these original forms. Although there are differences in certain aspects from the original tales to the movies, there are many issues that are influential to the young girls who are still watching the Disney version. I realize this when my youngest niece, Anella asks me, “Why can’t I be beautiful and fall asleep and suddenly wake up to finally find my prince?” This is true in all cases of the four different translations of the fairytales. Every single girl in these stories are in a “beautiful” state of half-death who wake to find a prince who if eager to carry them off. This can lead to negative psychological effects on young girls as they are growing up, creating a large amount of pressure and low self-esteem due to the beauty that these stories portray and maintaining restrictions that these women experience in the stories. While it is true that Sleeping Beauty and Snow White and the Seven Dwarves are considered Disney classics that entertain children and provide meaningful role models, it is evident that the true, vulgar nature of these tales are hidden; these stories are about women who are thrown away.
The Cuban Missile Crisis was not only the tensest confrontation between these two nations; it was also the most controversial. There have been many different theories as to why the Soviet Union set up nuclear-armed missiles in Cuba in the first place. One theory suggests that Stalin’s successor, Nikita Khrushchev, placed these weapons in Cuba because he felt endangered by the United States’ nuclear missiles in Turkey, which were a threat to the Soviet Union. Another theory proposes that Castro feared for another US invasion in Cuba, thus enlisting the help of their communist allies. Since the unsuccessful attack at the Bay of Pigs, Castro feared for another invasion, perhaps a more successful one of Cuba. But nonetheless, the Cuban Missile Crisis proves to be successful in which we avoided a nuclear war.
The Cuban Missile Crisis most definitively is known for how it halted nuclear attack on the brink of a hot war. With missiles in Cuba and Turkey pointing at each other, a stalemate was created between the Soviet Union and the United States. A policy of Mutually Assured Destruction was followed in order to prevent either side from attacking the other in fear of mass amounts of death and environmental consequences that would be caused by a nuclear war between the two most powerful countries in the world. The United States had always had weapons in Turkey within the region of the Soviet Union, being threatened by this the leader of the Soviet Union, Nikita Khrushchev order for missiles to be sent to the communist ally in the caribbean which was Cuba led by former revolutionary Fidel Castro. After this event had occurred President Kennedy addressed the nation and the world on how the U.S. would respond to such threats. “ This urgent transformation of Cuba into an important strategic base--by the presence of these large, long range, and clearly offensive weapons of sudden mass destruction--co...
Similar to the above conversation, one must take these tales with a grain of salt, and keep in mind the time period in which they were written. For the purpose of this paper, the focus will only be on what the tale is striving to teach those who read it. Similar to Lurie’s opinion on “The Light Princess,” readers of “Sleeping Beauty” may come away from the story thinking the best was to grow up or be helped is to fall in love; let the man (prince) solve the problem (Lurie 360). This thought is further echoed by Martin Hallett and Barbara Karasek, the authors of “Folk and Fairy Tales,” as they describe the story “as a metaphor for growing up: the heroine falls asleep as a naïve girl and awakens as a mature young woman on the threshold of marriage”
Fairy tales portray wonderful, elaborate, and colorful worlds as well as chilling, frightening, dark worlds in which ugly beasts are transformed into princes and evil persons are turned to stones and good persons back to flesh (Guroian). Fairytales have long been a part of our world and have taken several forms ranging from simple bedtime stories to intricate plays, musicals, and movies. However, these seemingly simple stories are about much more than pixie dust and poisoned apples. One could compare fairytales to the new Chef Boyardee; Chef Boyardee hides vegetables in its ravioli while fairytales hide society’s morals and many life lessons in these outwardly simple children stories. Because of this fairytales have long been instruments used to instruct children on the morals of their culture. They use stories to teach children that the rude and cruel do not succeed in life in the long run. They teach children that they should strive to be kind, caring, and giving like the longsuffering protagonists of the fairytale stories. Also, they teach that good does ultimately defeat evil. Fairy tales are not just simple bedtime stories; they have long been introducing cultural moral values into young children.
The nursing policy and procedure this author chose to further research was obtaining blood cultures from central catheters. Peripheral blood culture sampling is preferred due to less probability of contamination and has a higher bacteria specificity rate (Halm, Hickson, Stein, Tanner, & VanderGraaf, 2011), but there are instances where a sample for a culture is specifically warranted and ordered from a central catheter line. Due to the infrequency of this sample acquiring, nurses must gain familiarity with the correct policy and procedure to obtain these samples this is why this nurse chose this particular procedure.
Previous climate change predictions have provided scientists, archaeologist and ecologists with information about the past and future of humans. These indications are backed up by scientific research based off of the physics of the Earth’s atmosphere, ocean, land and ice. In addition, many researchers have recently turned their focus to past civilizations and their downfall. With information from Mark Kinver’s “Roman Rise and Fall ‘Recorded in Trees’” studies show that from the demise of the Argaric society to the fall of the Mayan, and Ancient Roman Empire, climate change has played a key role in regards to civilizations collapse and nuclear annihilation.
Graham, Allison. "50 years after Cuban missile crisis: closer than you thought to World War III." The Christian Science Monitor, 2012. Web. 4 Nov 2013.
living on earth disappeared. So how did these dominant creatures just die off? Was it a
It is known that in the last 650,000 years there have been seven cycles of glacial advance and retreat with the last one 7,000 years ago. This was when the modern climate era started which lead to the beginning of human civilization all