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theories about dinosaurs extinction
theories about dinosaurs extinction
Short note on extinction of dinosaur
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Theories on Dinosaur Extinction
What killed the dinosaurs? Several theories have been brought up over time to answer this question. It has been of vast interest to many scientists how creatures the size of the dinosaurs could have been wiped out of existence.
Proposed Theories
Climate Change Theory
Some scientists propose that climate change was killing the dinosaurs before the famous asteroid struck. Fossil evidence shows that the average temperature had dropped from 25 degrees Celsius to 15 degrees Celsius and that the amount of annual rainfall had decreased. Fossil evidence also shows that more than half of the dinosaurs (many large plant-eating dinosaurs), crocodiles, and turtles of the time were gone before the asteroid struck in the Cretaceous period.
The Firestorm Theory
At one point it was thought that an impact from an asteroid combined with volcanic activity would have created mass numbers of firestorms with ground temperatures reaching 1000 degrees Celsius. It was thought that anything that was not destroyed directly from the fires would have died due to blocked sunlight as a result from the soot.
However, new studies have shown that rocks from the supposed time of impact contain little charcoal. In order for it to be possible for the massive firestorms to have occurred, charcoal would have had to have been present in the rocks. Without charcoal there is little likelihood that this theory is true.
Still, some debate that although some investigations claim to have not found charcoal in the rocks, they fail to report that they did find coal. These skeptics claim that coal is not easily distinguishable from charcoal and point out that it is possible that investigators missed signific...
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“Scientists seek new clues to dinosaur demise.” Geographical v.73 i3, (2001): 10. In InfoTrac Onefile Plus [database online]. Cited 3 April 2004. Available from Ithaca College Libraries.
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"Janie saw her life like a great tree in leaf with the things suffered, things enjoyed, things done and undone. Dawn and doom was in the branches" (8). When Janie was a teenager, she used to sit under the pear tree and dream about being a tree in bloom. She longs for something more. When she is 16, she kisses Johnny Taylor to see if this is what she looks for. Nanny sees her kiss him, and says that Janie is now a woman. In Their Eyes Were Watching God, Janie, the main character, is involved in three very different relationships. Zora Neale Hurston, the author, explains how Janie learns some valuable lessons about marriage, integrity, and love and happiness from her relationships with Logan Killicks, Joe Starks, and Tea Cake.
People are constantly searching for their voices. A voice gives someone independence and the ability to make her own decision. The First Amendment ensures that all United States citizens possess the freedom of speech; however, not all people are given the ability or opportunity to exercise that right. When a person has no voice they rely on others to make their decisions. Throughout Zora Neale Hurston’s Their Eyes Are Watching God, Janie constantly struggles to find her voice. Her marriage to Logan Killicks, Joe Starks, and Tea Cake help her discover and utilize her voice in different ways. During Janie’s first marriage to Logan she has no voice, Joe silences Janie’s tiniest whisper and controls her similar to a slave; in contrast to Logan and Joe, Tea Cake encourages Janie to use her voice and make her own decisions. Janie cannot express her voice until she discovers happiness and independence through her final marriage.
Tea Cake - Janie's third husband. He is understanding and warm. As he accepts her as herself, he also gets worked up and harms her a few times.
...out what is for her and how she wants to live. So in the end, she is where she wants to be. Janie pulls in the horizon that she has spent her whole life searching for. She calls her soul to come in and see. Where once her soul was separate from her, it is now a part of her. Janie grew throughout the novel into a strong and independent woman. Although Janie cared for Tea Cake, she needed to kill him in order to keep him from suffering. Janie shows the reader that she has lived her life fully the way she wanted too and is now able to die having no regrets in life. Although Janie did recognize that most men were obsessed with power and thrived for complete control, she did discover a man who helped push her to her goals. Tea Cake helped Janie a lot, but he made sure she did not rely on him because from the moment they met, he knew how strong of a woman Janie truly was.
So many people in modern society have lost their voices. Laryngitis is not the cause of this sad situation-- they silence themselves, and have been doing so for decades. For many, not having a voice is acceptable socially and internally, because it frees them from the responsibility of having to maintain opinions. For Janie Crawford, it was not: she finds her voice among those lost within the pages of Zora Neale Hurston’s famed novel, Their Eyes Were Watching God. This dynamic character’s natural intelligence, talent for speaking, and uncommon insights made her the perfect candidate to develop into the outspoken, individual woman she has wanted to be all along.
...ruel journey towards a true self-revelation of herself. Starting with her teen years, she was hassled by her Grandmother to marry for stability and money, not love. She would then follow a man with a big voice to escape the laborious and unaffectionate life with Logan to marry Jody. Realizing that Jody was an even bigger nuisance for a much longer period of time, she would then go on to marry Tea Cake. Janie has returned to her own place, as her own woman, with her own memories to guide and comfort her. Although she grieves Tea Cake's unfortunate death, she has come back a wiser person and is stronger because of it. She will keep Tea Cake alive in heart to keep her company and live joyfully in the next stage of her life knowing that Tea Cake helped her realize her capacity to mature into a loving adult and actually love a person to the fullest extent possible.
After two failed marriages, Janie finally gets a sense of freedom. Soon enough she meets Tea Cake when he comes into the store and asks her to play a game of checkers with him. The narration of their first meeting lets readers know what Janie thinks about Tea Cake, while also showing Janie’s control in her storytelling to Phoeby. The contrast between Janie’s behavior toward Tea Cake and her behavior towards her ex-husbands foreshadows an equal relationship between the two, making her closer to her goal of finding her own voice. Tea Cake’s name evokes an image of sweetness, and Janie gives him a “little cut-eye look to get her meaning,” Because there were no images attributed to Joe and Logan, readers know that Tea Cake and his sweetness will help Janie’s goal. The last image of the moon rising with its “amber fluid drenching the earth and quenching the thirst of the day” signifies a new day in Janie’s life, as talking to Tea Cake quenches Janie’s thirst for a voice and individ...
Janie is older, more mature and understanding of the real world, when meeting Tea Cake she’s hesitant to pursue a relationship with him. Here the reader can see how these past two marriages have affected Janie’s perspective on marriages and the way it’s utilized by Hurston will help with Janie’s development as a character and her understanding of happiness. The marriage between Janie and Tea Cake is much more composed and open, Tea Cake is more emotionally connected to Janie and much more understanding of her needs that her previous two husbands were. With the first marriage Janie was introduced to reality, and within this reality she couldn’t be happy because she didn’t understand how to deal with the reality given to her, in turn her marriage with Tea Cake takes her away from reality in the context of her understanding and being able to react in a way that allows her to be
In the end, Janie found herself being defined by other people, so to say Logan, Joe, and Tea Cake. During her marriage to Logan, Janie is viewed as a spoiled and non-hard working girl that needs to learn what it means to make a living. In her marriage to Joe, Janie is only needed for her outward appearance for him to define as his possession; never did he consult her about what she wanted. In both of these relationships she was forced to be something that she was not. Once Tea Cake came along everything had changed; going from following another man’s orders to being able to live a fun-loving life. Throughout the time she spends with him, finally free from being defined by someone else, Janie Crawford discovers who she is and what love is.
N.A. "Virus, not asteroid or volcano, may have doomed dinosaurs." USA Today n.d.: Academic Search Premier. Web. 13 Jan. 2014.
The disaster theory, Gould claims, is an example of good science. It has testable evidence and has an impact on studies in other fields of science, it develops further and explains why the extinction of dinosaurs occurred simultaneously with other events. This theory suggests that a large comet hit the Earth sixty five million years ago, causing the cloud of dust to rise into the sky and to block sunlight. As a result, world temperatures went down significantly, the ice age bega...
Although great amounts of ash suggest that most of North and South America was devastated by fire from the impact, the longer-term environmental effects of the impact were ultimately more deadly to life than the fire. Dust blocked sunlight from the earth's surface for many months. Burned sulfur from the impact site, water vapor and chlorine from the oceans, and nitrogen from the air combined to produce a worldwide fallout of intensely acidic rain. Scientists postulate that darkness and acid rain caused plant growth to die. As a result, both the herbivorous dinosaurs, which were dependent on plants for food, as well as the carnivorous dinosaurs, which fed on the herbivores, died out. On the other hand, animals such as frogs, lizards, and small insect-eating turtles and mammals, which were dependent on organisms that fed on decaying plant material, were more likely to live.
War is a patriotic act where one seeks the determination to lead their country. It can be viewed noble, cruel, inhumane and can make an individual a hero or a criminal. It effects everyone in a society, hoping their loved one is safe whether fighting in the trenches or waiting at home. It has led to severe individuals suffering from posttraumatic stress disorder. Two poems in war literature “Anthem for Doomed Youth” by Wilfred Owen and “Facing it” by Yusef Komunyakaa, the authors’ different perspectives will be presented. Owen portrays war as a horror battlefield not to be experienced and the glorious feeling to fight for one’s country. Komunyakaa on the other hand shows an African American that serves in Vietnam War and visits the Vietnam Veterans Memorial Wall. The poets’ choice of diction, setting of battlefield and various uses of poetic devices create a desired effect.
The K-T Extinction occurred 65 million years ago. Many species perished in that extinction. Today evidence for this extinction can be seen in the fossil record. Biological, botanical and geological evidence at the Cretaceous – Tertiary Boundary show that some enormous event occurred that caused mass extinction of life on the Earth. Controversy about the cause of the K-T extinction exists with two main theories currently being in favour. One theory is called Intrinsic Gradualism and believes the cause of the K-T Extinction was a slow and gradual Earth generated event, caused by intense volcanic activity and the effect of plate tectonics. The second theory is known as Extrinsic Catastrophism and proposes that the K-T Extinction was caused by a sudden and violent catastrophic event such as the Earth being struck by a meteor or asteroid. The K-T Extinction supports the concept of Punctuated Equilibrium in evolution because surviving species evolved and others were exterminated. This creates the stepladder effect of evolution seen in the fossil record .
Owen’s poem uses symbolism to bring home the harsh reality of war the speaker has experienced and forces the reader to think about the reality presented in romanticized poetry that treats war gently. He utilizes language that imparts the speakers experiences, as well as what he, his companions, and the dying man feels. People really die and suffer and live through nightmares during a war; Owen forcefully demonstrates this in “Dulce et Decorum Est”. He examines the horrific quality of World War I and transports the reader into the intense imagery of the emotion and experience of the speaker.