The Sixth Extinction Essay SamEssay Sample on The Sixth Extinction by Elizabeth Kolbert ple

The Sixth Extinction is a fascinating look into the concept of extinctions in history. From the current crisis of frogs in Central America, to the meteor that killed the dinosaurs, extinctions are a part of life on Earth. However this idea was not always known and accepted. It took the work of several very dedicated and highly inquisitive scientists to give these ideas life and give them prominence in the scientific community. The first few chapters of the book take a look at the debates and the evidence that would eventually hold up these ideas in detail and allow the reader a look into the evolution of extinction theories. 

The First Chapter of “The Sixth Extinction” is a very somber introduction to the topic of a potential mass extinction event. The narrator has spent years around the topic of rapidly disappearing amphibians all around the world, but specifically the many unique species of frogs in the rainforest of South and Central America. Much of the chapter is centered around the EVACC amphibian research center located in El Valle. This research center houses several diverse species of frogs, salamanders, and other amphibians that had been mysteriously disappearing for years. Edguardo Griffith is the director and one of the most experienced researchers at the EVACC facility, he has been at the facility since its completion and he has been a very important figure in the conservation of these frogs. The frogs that have been disappearing in Central America and all over the globe have been found to have been in contact with a fungus known as BD. 

BD or Batrachochytrium Dendrobatidis is a unique form of Chytrid fungi that has shown to stop the reception of vital electrolytes in frogs which in turn causes a sort of heart attack which kills the frogs. It is thought that the fungus was brought to the various places on the globe through trade of BD immune frog species. Whether they had been transported for research, consumption, or other purposes, this world wide frog transit is thought to be responsible for the spread of BD. BD was first discovered by a Washington D.C. zoo researcher whose blue poison dart frogs had mysteriously become ill. The researcher took lab samples of their skin and found the first traces of BD. These samples were grown into full form fungi and reintroduced to a small group of frogs all of whom would die from the fungi. Other frogs around the globe were then found to have been in contact with the fungus and areas such as tree canopies and forest floors where frogs are frequently found, were shown to have high concentrations of this fungus. BD has claimed several species of frog and is the main culprit behind what many are deeming a sixth mass extinction. It is thought that the current rate of extinction of frogs is several hundreds of times faster than their natural rate of extinction.

Chapter two discusses the idea of extinction and how it seems to be an obvious concept. In the modern day, children are capable of grasping the topic of extinct dinosaurs but as explained in the chapter, the idea of extinction is barely as old as the United States. The first idea surrounding unusual bones that had been discovered in Russia and the Americas, had been that they were simply undiscovered species or bones that had been moved around the globe during severe natural disasters such as the bible's great flood. This was the commonly accepted narrative until a man named Cuvier presented the idea of extinct animals. He provided proof for his theory through several unusual sets of bones that France had in its possession. While the idea was radical at the time he was able to gain traction and spread his ideas throughout the newly established French Republic. 

Many peculiar fossils had been discovered in Russia, The Netherlands, as well as the Americas. However it was the fossils from the Ohio area of the French colonies, these ideas may have never come about. The American Mastodon fossils were the topic of great debate as if they were a single animal, or multiple animals. Then popular theory before Cuvier presented the extinction theory, was that all animals were a lineage and had existed since creation. As such Cuvier’s ideas presented a direct challenge to the status quo and were largely criticized, however, his grand ideas soon took hold and are now the standard today. 

Cuvier was the first to identify and name many species that had been unknown before him, such as the Pterodactyl, the American mastodon, and the wooly mammoth. Cuvier's discoveries were groundbreaking and he even proposed the idea of a world that came before our own, a world of animals that no longer inhabit the earth. If his ideas were correct, as they were later proven to be, there should be countless numbers of these fossils that would be located all over the Earth. 

Cuvier not only created and popularised the idea of extinction, he was able to link animals together to some degree. Animals such as the wooly mammoth and the elephant were figured to come from a similar group of species.

In chapter 3, the narrator discusses the opposition to Cuvier’s ideas on extinction and extinction events. A British scientist by the name of Lyell vehemently opposed the idea of cataclysmic extinction events and published many of his own ideas that discounted large scale and sudden extinction. Lyell sold many copies of his works and was known to be a sort of celebrity. One of his books found its way to a young scientist by the name of Charles Darwin, who quickly read all of the works of Lyell and used them to form his own scientific theories. Many of Darwin’s theories were supported by Lyell, even a few that contradicted his own ideas, as he believed the reasoning to be sound. Darwin and Lyell had a sort of friendship due to the shared belief in Darwin's ideas. However, once Darwin introduced his idea of Natural selection and evolution, it created a rift between the friends. Lyell believed that these ideas had no real backing and as such refused to adopt them. 

Darwin also opposed the idea of mass extinction events and believed that animals simply were phased out gradually. Evolution was the only factor in extinction and no other outside force was needed. However, during Darwin’s lifetime, a couple animal extinctions took place. The Great Auks of Iceland found themselves hunted to extinction by travelers. This event did not fit into his theory of gradual evolution and competition. This extinction was simply caused by an outside force that had and would continue to cause the extinction of hundreds of species over short periods of time. The conclusions from the human caused extinction of the great auks was that extinction events are possible and are a real possibility for many animals. Cuvier once again proved to be ahead of his time and correct in the idea of mass extinction events. 

Chapter 4 covers the confirmation of the crisis theories that were first introduced by Cuvier. A family of scientists in California discovered an inconsistency in fossils and iridium levels in certain layers of clay in several locations all over the world. These samples were thought to be proof of an extinction crisis that is responsible for having taken out dinosaurs and several other major species tens of millions of years ago. The father and son duo gathered evidence and published their findings, only to be disregarded by the larger paleontological community. While the paleontology community as a whole rejected the findings, the Alvarez family continued their work. They acquired more iridium rich clay samples from all over the world and even discovered a type of rock called shock quartz in Texas that is thought to have been formed by a large tsunami. The final piece of the puzzle was the discovery of the impact crater in the Mexican peninsula. This crater had been buried under sediment and was rediscovered in the search for evidence. All of the findings were put together by the younger Alvarez and this time, it was widely accepted instead of rejected.

The impact theory has been debated for years since its acceptance. It is unclear what the true cause of the extinction was. It is agreed that a large meteor impacted the Earth, but was it a large scale winter that eventually froze all life on Earth, was it potentially a burning wave of particles that swept over the surface of Earth and burned most life forms present, or was it a potentially unknown side effect of the meteor that caused the extinctions. 

While these theories of extinction and subsequently mass extinction events, had been largely discredited and debated for hundreds of years, it is due to the work of a diligent and focused scientist that we know what we know today. While the ideas of extinctions such as the one that killed the dinosaurs are simply a known fact that even children are known to expect, it was not always this way. Extinctions have happened all throughout history and are even happening today with species of frogs and other critically endangered animals, but even just a few decades ago, this may not have been thought of as possible.