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Million Years Ago 65 Million Years
2,114 wordsThe "Nemesis Theory" was an outgrowth of the discovery of Alvarez et al. , that the impact of a large (10 km diameter) comet or asteroid was responsible for the great mass extinction that took place 65 million years ago. Studies of the fossil record by Dave Raup and Jack Sepkoski shows that this was not an isolated event, but one of several mass extinctions that appear to occur on a regular 26 million year cycle. Their original paper analyzed marine fossil families, and was published in the Proc...
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The End Permian Mass Extinction
3,006 wordsIntroduction Think of a world which existed 290 million years ago. As you look out over the trade in front of you, you think that you are on an alien planet. You see volcanoes spewing ash and lava. Beside them is the ocean which is swarming with many different species of echinoderms, bryozoans and brachiopods. As you look down onto the sea floor you are amazed at the countless number of starfish and urchins. Some animals leave you can't even describe and you have no idea even what phylum they be...
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The End Permian Mass Extinction
3,001 words... verify the Chinese reports of iridium and they are fruitless. Anomalies can cause a build up of iridium in one place which would lead to what the Chinese have discovered (Erwin, 1993). Cosmic Radiation Global Cooling Global Warming Salinity The hypothesis that salinity decrease caused the mass extinction of oceanic life was first formed by Beurlen in 1956 (Maxwell, 1989). Evidence for this phenomena was based mainly on stenohaline groups such as the bryozoans, ostracods and corals which were...
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One Of The Most Important Endangered Species
1,089 wordsOut of all the species that have ever existed since the beginning of time, 98 % of them are extinct (Facts). There are an estimated 5 - 10 million species that exist currently and only 1. 5 million have been identified (Sherry, 2). Scientists classify species into six different groups: plants, animals, insects, algae, fungi, and microorganisms (Todays Situation). In the tropical rainforest alone, most species are disappearing at the rate of 1 % a year (Sherry, 6). If the current trend continues,...
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Endangered Species Tropical Forests
827 wordsIssues that surround the dramatic declines of species are complex, often conflict-laden, and not easy to reverse. However, one can learn from past practices, improve performance, and avoid the problems common to endangered species conservation. Outline Introduction Body Species extinction causes Florida panthers Tigers and snow leopards Turtles Conclusion Endangered Wildlife As human population and needs (real or perceived) expand, the globe becomes scarred by a deadly scythe. Our planet is losi...
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Permian Extinction Mass Extinction
537 wordsThe Mother of All Extinctions The article deals with the question that has been argued about by biologists and geologists for many years now. In the history of Earth, there were a number of mass extinction events that left their track in the geological record. This particular article addresses the largest one that ever happened, The Permian extinction which took place about 250 million years ago and destroyed 90 % of all living forms on Earth. Until recent time, the Permian extinction was not so...
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Taking Into Account Lava Flows
1,159 wordsWhat event occurred at the division between the Triassic and Jurassic periods, and why was this important to the dinosaurs? The extinction is a topic that now requires rather more digging than talking. The Triassic and Jurassic periods were remarked by changes that influenced both: relief and biologic forms of life. The dinosaurs were the most typical representatives of fauna for the Triassic and Jurassic periods. These periods are characterized by tectonic activity, worsening of climate conditi...
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Million Years Ago Permian Extinction
1,401 wordsAnthropology Is human extinction possible? Why does this happen? What causes a species to be extinct? Can human race prevent it? To answer these questions we must first define what extinction means, what types are there and why do they occur. As extinction is a continual product of natural selection, since the dawn of competition spawned by the first meiosis event, natural selection has altered all life on earth, precariously engaging in life experiments some that work and some that dont. Those ...
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000 Years Ago Stone Tools
3,216 wordsTroublesome Questions In 1830 Mr. Rankin tied a rope around a projection out of a rock face in order to lower himself into Wellington Cave (Horton, 1980). The projection turned out to be the bone of a giant extinct marsupial. It was to be the first discovery of a great range of giant marsupials. Were these animals extinct? ? Horton (1980), describes how Leichhart believed that on his journeys to northern Australia he would find Diprotodon still roaming over the land. We now know that he was prob...
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Million Years Ago Mass Extinction
10,014 wordsEarth probably began Extinction Introduction Earth probably began about 4. 5 billion years ago. A history of this life on Earth is recorded in fossil remains and traces of past life. It is a record of evolution for both life and the planet. Life and the planet have co-evolved, with life causing changes to the planet which in turn drive changes in life. The Fossil Record A history of these changes is recorded in the layers or strata of rock laid down over the millions of years, and by changes in ...
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Million Years Ago 65 Million Years
1,623 wordsThe first question that must be posed when trying to crack the mystery of the mass extinction is to ask, throughout history were there any other occurences of this magnitude? The answer is a resounding yes. Altogether over time there has been about eight mass extinctions to large land dwelling vertebrates. The most recent was about ten thousand years ago, killing most of the giant mammals like mammoths, mastodons, super-large camels, saber-toothed tigers, and others (Bakker 428). The second ques...
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Million Years Ago 65 Million Years
1,087 wordsWHERE DID THEY GO? BY JOHN J. HATFIELD EARTH SCIENCE LAB 2234 TERM 2 INTRODUCTION The biggest mystery surrounding the dinosaur is how did they die? For over 130 million years dinosaurs ruled the earth. Then 65 million years ago, at the end of the Cretaceous period, they died out. Nobody can really say what actually eliminated the species, although everyone has their very own idea. Asteroid impact, atmospheric changes (hot to cold), catastrophic eruptions and astronomical events (supernovas etc. ...
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Darwin Theory Theories
4,032 wordsLamarck? s Influence On The Development Of Lamarck? s Influence On The Development Of Darwin? s Theory Of Evolution Lamarck? s Influence on the Development of Darwin? s Theory of Evolution Serebryany, Rostislav Marc Weinstein Lamarck? s Influence on The Development of Darwin? s Theory of Evolution There have been many ideas on the theory of evolution. Some simply take our existence for granted, others prefer to explain all evolution in terms of the bible and the presence of a God. However, there...
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Permian Extinction Mass Extinction
6,021 wordsThe End Permian Mass Extinction Introduction Think of a world which existed 290 million years ago. As you look out over the trade in front of you, you think that you are on an alien planet. You see volcanoes spewing ash and lava. Beside them is the ocean which is swarming with many different species of echinoderms, bryozoans and brachiopods. As you look down onto the sea floor you are amazed at the countless number of starfish and urchins. Some animals leave you can t even describe and you have ...
Free research essays on topics related to: carbon dioxide, extinction, mass extinction, permian extinction, oceanic crust
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