Walter's Theory Of Mass Extinction essay example
For 65 million years, the story of the dinosaurs has been frozen in time at the small layer of clay called the "K-T boundary". It was in the early 1970's, when studying this layer of clay, that Walter Alvarez began making discoveries within the clay strata. One discovery found within the K-T boundary was several types of ejecta deposits. Among the deposits were an abundant source of spherules, tektites and other unusual fragments. Walter thought that they may have been created under the immense heat of an impacting meteor and then flung under the shock of the impact. A metamorphic rock created under such an environment could be the crucial evidence of an impact, if the right tool could be found- radiometric age dating.
At the time, it was already well known that the dinosaurs died out about 65 millions ago, but the process of dating the new metamorphic rocks unique to the K-T boundary would bring about new confirmation of a cataclysmic event. Using these discoveries, Walter was able to make great advances in establishing evidence for the theory of a global mass extinction from an extraterrestrial origin. Slowly and under much scrutiny the case for an impact was coming to life. Possibly the most astonishing thing that Walter uncovered in the K-T Boundary was an anomaly of extremely high iridium levels. What the anomaly found was that there was an iridium concentration of 9.1 ppb (parts per billion) at the K-T boundary.
Because iridium exists within earth's crust at 0.03 ppb, this dramatic increase would demand an explanation extremely out of the ordinary. Now, all elements that are heavier than helium are found in the composition of supernovas and from meteorites scattered around from supernova explosions. Therefore, Walter knew that he was on to something. For finding trace elements at levels such as these, not only pointed to an extraterrestrial event, but confirmed the theory of a global mass extinction caused by a meteoric impact, as it was the only possible theory that incorporated events not of this Earth. By 1981, the presence of the high iridium anomaly in nearly every K-T boundary was established as fact, as was the theory of a sudden extinction from an impact. When the puzzle pieces are put together, Walter was able to conclude where the meteor struck, and what happened as a result of that impact.
Walter concluded that the meteor hit the Yucatan peninsula producing a number of events. In short, the initial impact on the enormous meteor ceased to be recognizable as it drove itself into the ground creating shock waves both in and out of the water. Within seconds, melted fragments of rock and other ejecta was flung in every direction. Much of the meteor was vaporized on contact allowing iridium and toxic gases to saturate the sky only later to rain down marking the K-T boundary. Within hours, a tsunami was heading for the shorelines of North America ultimately bringing all the necessary clues to unravel that mystery, resulting in a mass extinction of more than 70% of the Earth's plant and animal population.
With this theory, Walter had solved the mystery by putting together the pieces of evidence, found through a journey of scientific discovery. This journey of discoveries, however, was not always his alone. In fact, they were rarely his alone, for they were often accompanied by many people from numerous scientific fields, including even his father, a renowned physicist named Luis Alvarez. These collaborations were of paramount importance, because the answer to the mystery of the dinosaurs could not be explained purely through the perspective of geology. To geologists and paleontologists, the age old uniformatarianism view, meaning that past global changes could be understood by studying processes that can be seen going on earth today, would keep them from seeing this possibility.
It was brought to them by their predecessors in a form liking to conclusive fact; not as a discovery or theory, but as a fundamental principle of geology. Gradual extinction was viewed as the perfect fit whether it was climate changes or fall in sea level; the event was view as anything but sudden. Walter's theory of mass extinction went against the uniformatarianism view, because in order to understand the event that lead to extinction, they would have to look beyond what is happening today. It is for this reason that Walter's view was dismissed. However, this was true for all fields of science, not just geology. All scientists work within a fixed set of fundamental principles which lay within the confines of a paradigm, and anything that falls outside that paradigm is immediately dismissed.
Take biology for example. From a biologist's standpoint, the cataclysmic event would challenge Darwin's relationship between extinction and natural selection. The concept of natural selection states that species continuously adapt favorable traits in order to survive normal stresses of gradual environment change. Although the geologic record shows catastrophic events such as floods, earthquakes and volcanoes, those extinctions were limited only to the geographical area. These occurrences were incapable of causing a global extinction.
Only a cataclysmic event like that found at the K-T boundary site shows such an event. The survivors of that were no more successful than those that became extinct. Therefore, Darwin's "survival of the fittest" would not have any bearing on the population. In a cataclysmic event, survival would lay purely on the luck of the individual, and henceforth such a theory was rejected. The opponents of Walter and his father's theories were only behaving as scientists have done throughout history. Merging any two sciences together could overthrow the fundamental principles in either branch.
Therefore, regardless of the evidence, most scientists were not ready to give up on their prevailing doctrine. However, in Walter's opinion, cooperation from other fields was essential for success. A geologists' understanding of rocks and the metamorphism one undergoes under extreme temperature and pressure was proof positive on the possibilities of a major impact at ground zero. The field of chemistry offered the all important knowledge on the iridium anomaly from their expertise in identifying trace elements, as well as rock dating from their knowledge of radiometric age dating. Without even the support of sediment ologists, identifying different layers of deposits at the outcrops including meters of silt and sand layers, indicative of a tsunami, could never have taken place. All of these and more were necessary in proving the theory of global mass extinction by way of a meteoric impact, and Walter was one of the few people aware of this fact.
He knew that it was foolish for scientists to work against each other since each discipline had something profound to offer and that without comparing the scientific findings from all fields as a whole, the truth, in this or anything, could never be proven undeniably. Unfortunately for Walter, it ended up taking him years before he got the corroboration he was in search of. However, by seeking help through close colleagues when he was not able to unburden the weight of existing doctrine among scientists from other disciplines, he was able to find avenues to connect these different disciplines. Walter Alvarez's ability to think outside the preexisting box and against the so-called restrictions is in fact refreshing. He would not allow the limitations of geology fool him into the trap that so many fell victim. Walter understood that two minds are better than one, and ultimately joined forces with other scientists of different disciplines, something virtually unprecedented.
It was because of Walter's humble and creative thinking that the scientific world was able to uncover the mystery of the dinosaurs, and finally begin to function as one.