The Mystery of the Dinosaurs One of the most intriguing unsolved mysteries of science lies in the attempt to explain the mass extinction of dinosaurs. When posed with the question of explaining the relatively abrupt extinction of this particular species, a simple solution seems difficult to find. Several somewhat convincing arguments exist; however, many are vague and unfounded. Perhaps the only consistent characteristic among the popular ideas is that none are scientifically sound enough to be considered absolutely correct. Unfortunately, science requires undisputed factual support in order for a theory to be deemed law. This characteristic keeps the impact theory from being accepted as the answer to the mystery of the dinosaurs, even though it represents the best explanation. It can be seen as the best solution because it is the most popular and widely accepted theory which is evidenced by the fact that most contrasting views are more concerned with disproving the impact theory rather than establishing a new one. The one absolute fact in analyzing this dilemma is that a large scale extinction occurred in the dinosaur species around the Cretaceous-Tertiary boundary 65 million years ago. Catastrophic extinctions such as this are not unusual; in fact, fossil records indicate cyclical patterns of mass extinction incrementally spaced about every 26 to 30 million years. However, it is the elimination of such productive and fruitful creatures that makes the mystery of the dinosaurs so bewildering. In an effort to rationalize this phenomenon, Louis and Walter Alvarez proposed their impact theory which attributes the mass extinction of dinosaurs to the impacting of a large meteor on Earth. The Alvarez's suggest that the meteor, after colliding with Earth, raised an incredible amount of dust into the atmosphere, thus changing the climate of the Earth's surface for years. The change in climate is claimed to have occurred either in the form of global warming or from the dust blocking the sun, thus impeding plant growth. If the hindering of plant growth developed in this way, many dinosaurs would have starved to death. Several factors support this argument. The backbone of this theory lies in the high concentrations of iridium that the Alvarez party found at the Cretaceous-Tertiary boundary. Although the iridium was initially found in one particular site, future tests confirmed the high level of iridium at the Cretaceous-Tertiary boundary worldwide. The significance of this particular element is that it is not found on Earth in the high levels Alvarez found and is only prevalent in space at such excessive levels. Therefore, he proved some extraterrestrial meteor large enough to cause the globally increased levels of iridium must have entered the atmosphere and crashed into the Earth. Further evidence to the impact theory can be derived from fossil records that prove the dramatic changes in plant spores. The most revealing of these is the increase in fern spores. The fern is a resilient plant, however it is only able to compete with very simple plants. Higher forms of plant life tend to infringe on the growing space of the fern. Therefore, the abundance of fern spore fossils following the iridium layer shows that practically all other plant life was destroyed after the meteor impact; thus, supporting the theory that the dinosaurs starved to death. As I mentioned before, many people subscribe to the impact theory, but their are others who still contest it. Some scientists have found high levels of iridium in gases from the Kilauea volcano on Hawaii. The gases spewed from the volcano originated deep inside the Earth's mantle have created new questions to the impact theory. However, we know so little about the lower mantle that I think there is still too much room for speculation regarding its chemical contents. Other explanations to the mass extinction of dinosaurs could lie in the realms of disease, natural, dramatic climate changes, or something in the evolutionary process. Maybe the dinosaurs did not adapt properly, or even over-adapted; maybe they killed one another off; or, maybe by some divine power, certain species are only meant to have a limited life-span on Earth. Whatever the case, today no one knows the true explanation as to the mystery of the dinosaurs. However, I feel, after analyzing the Alvarez's impact theory, that it is the most conceivable, rational depiction of dinosaur extinction.
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