End Cretaceous Mass Extinction

At the beginning of the passage, he tells the readers that two of these theories are speculation and the other is pure science but each one is hard to dismiss. Testicular malfunction, the first example, cannot provide enough evidence to support this theory, solely because a paleontologist cannot extract samples and information from a fossil and simply because testicles do not fossilize. The scientists proving this theory, E. H. Colbert for an example, admitted that testicular malfunction is just a hypothesis. Therefore, Gould believes that this theory is merely unusable, but not as disadvantageous as psychoactive overdosing. Drug overdosing, like sex, can not be tested because again, like testicles, livers do not fossilize. In addition, there is also not enough evidence to prove this theory explicable, thus becoming another speculation proposal. Consequently, the theory of asteroidal zapping is the exponential scientific reasoning for dinosaur extinction. This theory can be proven by Luis and Walter Alvarez, a father-son geologist team, who became the first to propose the idea of asteroidal collision. The father and son duo collected sediment samples from deep in the Earth’s core in which they found extremely high amounts of iridium. Iridium is a highly testable chemical, therefore allowing the theory of asteroid and earth collision to be plausible. Gould’s final analysis proposes that asteroidal collision is the most scientific theory among the three. The author believes the asteroid colliding with earth and changing its temperatures allowed for evolution to happen. In summary, Gould distinctly and carefully analyzes the three theories, showing his reasoning for his scientific

Was it the confluence of events outlined in this review (including the prevailing global climate, volcanism), or are some of these factors secondary? For example, we have little idea of the mass of methane hydrates in the Late Permian ocean floor. These and many other questions will need to be addressed before we fully resolve the cause of the end-Permian mass extinction. However, there is a growing realisation that flood basalt volcanism has the potential to be the primary trigger for mass extinctions, rather than meteorite impacts or other external

In Stephen Jay Gould’s “Sex, Drugs, Disasters, and the Extinction of Dinosaurs”, Gould investigates three possible theories hypothesizing the reason behind the extinction of dinosaurs. The first theory suggests that dinosaurs became extinct due to a rise in temperature, which caused sperm to die, leading to the sterilization of male dinosaurs. The second hypothesis offer that many dinosaurs consumed bitter plants that contained psychoactive agents which their lives could not detoxify out of their systems. The last speculation about the dinosaur’s extinction is that a large cloud of dust formed in the atmosphere after an asteroid hit Earth’s surface. This dust cloud blocked out the sunlight, causing temperatures to drop and made photosynthesis impossible. Gould uses these three theories to lead to his central claim that science isn’t just about making fascinating claims, but should have a well developed hypothesis.

The scientists believe that the herbivores ran out of plants, and trees and so all of the herbivores died and after all of the herbivores died, all of the Carnivores died as well. Another theory is that a big asteroid hit the Earth, and the asteroid caused a global extinction.. The final theory that the scientists thought of happening was a disease. Disease may of happened from one dinosaur getting sick and then it just passed on from dinosaur to dinosaur.

Assess the different hypotheses put forward for the mass extinctions at the end of the Permian and Cretaceous (KT) Periods.

“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”

These techniques led to the discovery of the boundary between the two eras. A single thin layer of clay found within predominantly limestone rocks established this. By comparing the marine life found in, above, and below the clay, the marine life, like the dinosaurs, had been terribly affected by the extinction event. The percentage of life in the upper layers was dramatically lower than that in the lower. This was far more compelling than what was suggested by dinosaur’s fossils.

The extinction of the dinosaurs, absolutely a thrilling topic. In Steven Gould’s persuasive article he goes into great detail to describe the nature of science and it’s profound nature to help us in the pursuit of knowledge when used correctly. He then begins to describe three scenarios in which could’ve led to the extinction of the dinosaurs in which two while seemingly plausible at first glance are in actuality simply speculation. Thus, just like a good hypothesis using evidence to support his critiques and support of the hypotheses. Which is why I agree with Gould’s statement on how out of the three hypotheses, the extinction of the dinosaurs

There are a lot of theories about why the K-T extinction occurred, but a widely accepted theory was proposed in 1980 by a physicist named Luis Alvarez and his son Walter Alvarez who was a geologist. the theory is that an asteroid 4-9 miles (6-15 km) in diameter hit the Earth about 65 million years ago, creating the Chicxulub crater at the tip of Mexico's Yucatán Peninsula. The crater is more than 110 miles in diameter and 12 miles in depth. It is one of the largest confirmed impact structures on Earth; The impact would have penetrated the Earth's crust, scattering dust and debris into the atmosphere, and causing huge fires, tsunamis, severe storms with highly acidic rain , seismic activity, and perhaps even volcanic activity . The impact could have caused chemical changes in the Earth's atmosphere, increasing concentrations of sulfuric acid, nitric acid, and fluoride compounds. The heat from the impact's blast wave would have incinerated all the life forms in its path. The evidence for the impact was first discovered by Walter Alvarez and some of his colleagues. They found that rocks laid down precisely at the K-T boundary contain extraordinary amounts of the metal iridium. The dating is precise, and the iridium layer has been identified in more than one hundred places around the Earth. Where the boundary is in marine sediments, the iridium occurs in a layer just above the last Cretaceous microfossils, and the sediments above it contain Paleocene microfossils from the earliest part of the Cenozoic. Iridium is much rarer than gold on Earth, yet in the K-T boundary clay iridium is usually twice as abundant as gold, sometimes more than that. The same high ratio is found in meteorites. The Alvarez group therefore suggested that iridium was scattered worldwide from a cloud of debris that formed as an asteroid struck somewhere on Earth. Shocked quartz was

Many people often assume the asteroid completely wiped off the land and marine species with just the impact of the asteroid, but was rather the tipping point of what came next. In fact Choi stated that “ "We have shown that these events are synchronous to within a gnat's eyebrow, and therefore, the impact clearly played a major role in extinctions, but it probably wasn't just the impact.” ( Choi). The ultimate reasons for the dinosaurs and other species extinction was the blockage of sunlight which initially darkened and chilled to earth to extreme temperatures ( Jones). At this point many animals and even plants started to die off because of the chilling conditions, but that wasn't the only reason for the extinction of these species. Soon after the dust had settled and the earth was able to receive light, the planet initiated a greenhouse affect. Which not only put the remaining species at high temperatures, but their food also became inhabitable (Choi). The evidence of an asteroid theory is supported by the impact crater, rare metal, melted rock, fractured crystals, and the fossil record (Jones). The impact crater is actually one the main key examples of why the asteroid may have been responsible for the cretaceous mass extinction. It showed the asteroid landing on the Yucatan peninsula, and traveling at 30 kilometers per second (Jones). Not

The age of the planet Earth is estimated to be about four point six billion years old. Life on Earth is estimated to have started one billion years later. Evolution has taken place since then. Evolving life from simple forms into more complex forms through the course of time. It all began with single celled organisms, prokaryotes. Later evolving in a period of two hundred million years, cyanobacteria began to produce photosynthesis. And life went on, evolving, adapting to its home. However through this course of time, mass extinctions have taken place on planet Earth. One of the most recent mass extinctions, has as a matter of fact left various amounts of evidence of the creatures which roamed the Earth at that time. Such magnificent creatures which varied from a very small size to giant sizes. Creatures which are now known to humanity as dinosaurs. The name of this extinction was the Cretaceous-Tertiary Mass Extinction. This extinction took place roughly sixty five million years ago. It has not been too long since this incident compared to the life span of the Earth. And yet it is still unclear how this extinction occurred. Paleontologists to this day, debate on how this extinction occurred. A major factor on what caused this extinction to occur was an impact of an asteroid. Another theory such as sea level regression is considered to be the blame for the extinction. Sea level regression is the drop of sea levels which aids to explain the marine mass extinction, however

Imagine dinosaurs roaming the Earth minding their own business. Imagine them looking up to see a fiery, red ball of death. Imagine realizing that the blazing ball is an asteroid. Imagine it hitting the ground and nothing can be seen. The dinosaurs didn’t have to imagine that an asteroid was propelling down at them. They experienced it. Scientists have studied and calculated everything to know about the asteroid, the proof that it happened, what happened at the first impact, what resulted after the impact, and the evidence of how life of the dinosaurs changed before and after the colossal collision that eradicated the dinosaurs. The preponderance of evidence leaves little to no doubt that the dinosaurs went extinct due to an enormous

According to the research made by Alvarez (1980), it was due to an asteroid impact that single-handedly destroyed dinosaurs to extinction. Advocacy of this mechanism has been aided by the availability and tangibility of supporting evidence in the form of impact craters- the Chicxulub crater in the Yucatan Peninsula's date and timing of impact (dating produced an almost exact date of 65 million years ago), location, enormous size-170 km (Hildebrand et al.1991) and its high iridium content ( a metal not commonly found at the Earth's surface) make it seem that with a theoretical asteroid 10 km big caused the crater great damage at the end of the Cretaceous (Alvarez et al. 1980).

The four billion year history of earth has witnessed five mass extinctions, and some scientists believe that we are on the verge of the sixth.1[1] If we are in the midst of the next mass extinction, we are in the very early stages of an evolving, and escalating process. The most recent, or fifth mass of the extinctions occurred 65 million years ago at the boundary between the Cretaceous and Tertiary periods. Images of an asteroid colliding with the planet, decimating the dinosaur population have been in circulation since the early 80’s.2[2] Being the most recent mass extinction, thousands of scientists around the world have investigated it, and elementary school children are familiar with

The asteroid impact extinction theory began in 1980 with Luis and Walter Alvarez, a father and son team. They theorized that an asteroid struck the Earth at the close of the Cretaceous period, causing devastating effects and mass