The Sixth Extinction Chapter 7 - Elyonni Tordesillas

     Kolbert begins this chapter by talking about a place called One Tree Island, located near the Great Barrier Reef, in Australia. On the island, there’s a small research station affiliated with the University of Sydney. In the station, teams of scientists from around the world study the chemical composition of the nearby coral reefs. During her time on One Tree Island, Kolbert meets a scientist named Ken Caldeira. Caldeira’s research focuses on the impact of carbon dioxide on ocean pH, or acidity, but he has also studied the chemical composition of forests and the recent changes in global temperature. The first evidence that carbon dioxide could destroy coral reefs came in the late 1980s with the Biosphere Project in Arizona, which was a huge, glass structure designed to be a self-sustaining ecosystem. The project concluded that the high carbon dioxide levels eroded the composition of coral inside the Biosphere, challenging the common notion that coral reefs are immune to changes in carbon dioxide levels. In recent years, scientific studies have shown that coral reefs erode significantly when carbon dioxide levels rise in the surrounding water, meaning that, at the current rate of carbon dioxide levels, reefs are expected to “dissolve” in the next half-century. Coral reefs have come and gone throughout the planet’s history. In the Triassic Era, for example, nearly all the world’s reefs dissolved. It’s likely that coral reefs will disappear faster than they’ve disappeared at any point in the past, since they face the combined threats of carbon dioxide emissions, overfishing, and pollution. The rising temperature of ocean water also poses a significant threat to coral reefs. The disintegration of coral reefs isn’t unprecedented in planetary history, and rising water temperatures won’t destroy all life in the oceans. Some algae species will be able to thrive. Nevertheless, the destruction of the coral reefs due to human activity is a process that Kolbert presents as tragic. The reefs are beautiful and complex and they stand, symbolically, for the earth as a whole.

The Sixth Extinction Chapter 6 - Elyonni Tordesillas

      There is a small island in the middle of the Tyrrhenian Sea called Castello Aragonese. The island formed millions of years ago, due to the pressure between the African and Eurasian tectonic plates—a phenomenon that sometimes causes the release of carbon dioxide gas. Kolbert travels to Castello Aragonese in the winter in order to investigate the carbon dioxide levels of the surrounding waters. At Castello Aragonese, Kolbert meets two marine biologists named Jason Hall-Spencer and Maria Cristina Buia. Buia and Hall-Spencer take Kolbert scuba diving and they show her the huge green bubbles rising from the vents in the sea floor. Near the vents, there is very little sea life. Since the Industrial Revolution began in the early 19th century, human beings have burned huge quantities of fossil fuels (coal, oil, and natural gas), a process that has added many billions of  tones of carbon to the atmosphere. Humans have also cut down many trees, further increasing the amount of carbon in the air. At the current rate of growth, Kolbert believes, humans can expect the carbon dioxide concentration of the atmosphere to become double what it was before the Industrial Revolution began. The average world temperature could increase by as much as seven degrees Fahrenheit, melting the world’s glaciers and dramatically changing the marine environment. Scientists used to believe that burning fossil fuels didn’t alter the Earth’s atmosphere in any major way. Under the new paradigm, however, it seems clear that humanity’s fuel consumption will have major ramifications for the temperature and acidity of the oceans. 

The Sixth Extinction Chapter 5 - Elyonni Tordesillas

      Kolbert starts chapter 5 by introducing the ideas of Thomas Kuhn, the science historian who first proposed the concept of the “paradigm shift.” In 1949, there was a famous experiment in which students were asked to name a series of playing cards as the experimenters flipped them face-up. Some of the cards had been doctored—for example, there was a red six of spades (instead of the usual black card). When experimenters showed the cards quickly, students misread the cards; when they showed the cards more slowly, students were more likely to recognize their mistakes. The experiment proved to be an important influence on the thinking of Kuhn. Kuhn argued that, throughout history, humans are forced to adapt to changing environments. At first, they try to respond to their new environment using the same strategies and coping mechanisms they’ve already learned. But eventually, humans learn new strategies for living in their new environment, a new “paradigm” for survival. Kuhn's ideas about paradigm shift's were a good lens to use to study the history of evolutionary science. Elizabeth Kolbert states "The history of the science of extinction can be told as a series of paradigm." Essentially, what she is saying is how over the course of history different species are able to survive due to their ability to adapt. When scientists studied the first fossils, they tried to argue that these fossils belonged to living species. It took Cuvier to introduce the new paradigm: some animals go extinct. It took the Alvarezes, with their theory of an asteroid that wiped out the dinosaurs, to introduce the new paradigm of mass-extinction. Today, most scientists believe that species usually go extinct gradually, except when there’s a sudden, catastrophic event, in which case many species go extinct very quickly.

The Sixth Extinction Chapter 4 - Elyonni Tordesillas

      Elizabeth Kolbert introduces chapter 4 by explaining how the town of Gubbio, which is about a hundred miles north of Rome, might be described as a municipal fossil. Gubbio is notable for its beautiful limestone, including a massive limestone gorge with steep, smooth walls. In the 1970's it was here that geologist, Walter Alvarez, discovered traces of a huge asteroid—the asteroid, which, scientists later decided, hit the Earth during the Cretaceous period, causing the mass-extinction of the dinosaurs. The extinction of dinosaurs millions of years ago is arguably the most famous extinction in history. Walter Alvarez had come to Italy to study plate tectonics. Beneath the surface of the earth, he found layers of marine fossils, and he also noticed that there were thick layers of clay, containing no fossils, imbedded in the limestone of Gubbio. Walter found that clay contained huge amounts of iridium, suggesting that the clay may have originated in an asteroid. Further tests showed that there were thick layers of iridium dating back to the end of the Cretaceous period. In 1980, Luis and Walter Alvarez co-wrote an influential paper arguing that an asteroid containing iridium struck the Earth at the end of the Cretaceous period, killing the dinosaurs. Many biologists and paleontologist rejected Alvarez's idea of the mass extinction of dinosaurs. They pointed out that extinction is a slow, gradual process, not the result of a sudden catastrophe like an asteroid collision. The Alvarez theory of dinosaur extinction was “falsifiable,” meaning that further evidence could be offered to support or disprove the theory. In the decades following the appearance of the theory, new evidence surfaced that seemed to support the Alvarez. As a result, the scientific community came to accept the asteroid theory.

The Sixth Extinction Chapter 3 - Elyonni Tordesillas

     Elizabeth Kolbert opens chapter 3 by talking about William Whewell, president of the Geological Society of London in 1832, who coined an important word: “catastrophist.” While this word has taken on some new meanings since 1832,  To Whewell, a catastrophist  was a scientist who believed that the history of the planet was characterized by sudden, global catastrophes that caused large numbers of species to go extinct. Whewell had an associate, a geologist named Charles Lyell.  Lyell was an Oxford-educated scientist who’d been friendly with Cuvier. Lyell studied the rocks of Paris, Italy, and England, and found no evidence that there had been a global catastrophe that caused species to go extinct, all the evidence pointed to a slow, gradual process of erosion in the planet’s geological structure. Lyell concluded that, while some species certainly went extinct, extinction was a slow, gradual process, not a sudden, catastrophic mass death.  Lyell then became a well known author, famous for his research and ideas. One of his most prestigious readers happened to be a young Charles Darwin. He was incredibly inspired by Lyell, and often shared his research and ideas with him. In the book Elizabeth Kolbert states "Without Lyell there would have been no Darwin." Although Lyell was an important inspiration to Darwin, he believed that the geological world was changing in small, almost immeasurable ways, he didn’t believe in any theory of evolution. Darwin argued that there could be no extinction without the origin of new species. Life forms on Earth, he argued, were constantly in competition for the limited resources of food, water, and shelter. Species went extinct because other species had qualities that made them superior at finding food and shelter and reproducing. By the same logic, new species must appear over time, either surviving because of their superior qualities or dying out. This connects to the idea of "Natural Selection" which is the process that organisms better adapted to their environment tend to survive and produce more offspring.

The Sixth Extinction Chapter 2 - Elyonni Tordesillas

     Extinction is one of the first scientific concepts that children learn about. When small children play with toy dinosaurs they learn that the dinosaurs died a long time ago. In a way, a small child living in the 21st century has a better understanding of the history of life on Earth than scientists did thousands of years ago. In the second chapter, Kolbert states "Aristotle wrote a ten-book History of Animals without ever considering the possibility that animals actually had a history." Even today, there are some people who believe that no animals have ever gone extinct—or that the animals that went “extinct” drowned in the great flood described in the biblical book of Genesis. Scientist first proposed the concept of extinction in the late 18th century. A naturalist named Georges Cuvier studied the fossils of an animal now known as the American mastodon, or Mammut americanum, and concluded that all such creatures must have died out in the distant past. At the time, many people refused to believe his ideas, but now in the 21st century, it is proven that he was correct. Cuvier traveled around Europe, exhibiting his fossils while giving extraordinary lectures. One of Cuvier’s most famous discoveries was the pterodactyl, which he correctly identified as an extinct flying reptile. Kolbert meets with Pascal Tassy, the current director of the Paris Museum of Natural History. Tassy shows Kolbert the museum’s vast collection of elephant, mammoth, and mastodon remains, including the mastodon teeth that Longueuil found in Ohio. After going around the museum exploring the different fossils and artifacts, Kolbert states " With his lecture on the species of elephants, both living and fossil, Cuvier had succeeded in establishing extinction as a fact." Cuvier’s ideas paved the way for further ideas. For instance, the discovery of different fossils started by Cuvier led scientists to realize that older fossils were buried deeper, an insight that allowed them to estimate the fossils’ ages. This shows how science is a process that grows and evolves over time.

The Sixth Extinction Chapter 1 - Elyonni Tordesillas

        Throughout Chapter 1 of  The Sixth Extinction , Kolbert introduces the reader to a Panamanian town of El Valle de Anton. She explains how the the town is located within a massive volcanic crater. She then introduces the reader to an extremely common species of frog that lived in El Valle. The Panamanian Golden Frog became a staple in the community. Unfortunately, the Golden Frogs had begun to disappear suddenly in large numbers. Kolbert was so struck by the mass extinction of the species, she flew to Panama to research what had been going on. The disappearance of these frogs was seen as a crisis since amphibians are some of nature’s most resilient animals, capable of surviving in many different environments. "Amphibians are, after all, among the planets greatest survivors." The fact that the Golden Frogs were dying off so quickly caused others to believe that was was wiping them out was extremely dangerous. Kolbert later learns that an unidentified fungus called Bactrachochytrium dendrobatidis had spread to El Valle, and was responsible for the mass extinction of these frogs. Many people believe that the fungus had spread due to humans. Kolbert states "...African clawed frogs do not seem to be adversely affected by Bd, though they are widely infected with it...Without being loaded by someone onto a boat or a plane, it would have been impossible for a frog carrying Bd to get from Africa to Australia or North America to Europe."  Humans travel around the world, taking new diseases, fungi, and animals with them wherever they go. As Kolbert shows, humans are interfering with the natural equilibrium of the Earth, accelerating the process of mass extinction.

Chapter 13 : The Thing With Feathers (Angel Jorge)

In Chapter 13 of Elizabeth Kolbert's The Sixth Extinction, Kolbert takes us to San Diego at the Institute for Conservation Research to study the future of endangered or even currently extinct animals. This facility holds the DNA of these types of animals to preserve them and prevent extinction from happening again. It gives us another perspective of Kolbert's views on humans because of how mixed her opinion can sometimes be. She makes humans seem like a destructive, ambitious, abusive species yet here makes us seem like a forward-thinking society. "Kolbert speaks with Barbara Durrant, a reproductive physiologist, about extinction and survival. Durrant tells Kolbert about a Hawaiian crow named Kinohi. As Hawaiian crows are endangered, Durrant was trying to get Kinohi to reproduce, but she had no success. It’s indicative of how seriously humans take extinction that they are willing to spend thousands of hours getting crows, rhinos, and other species to bear offspring," (bookrags.com). Kolbert continues to speak about the 'Sixth Extinction' where humans are using their destructive nature to wipe out other species and mentions how humans have two options: either continue on this destructive path or change for the better and prevent any more death and extinction from occurring in the modern world. Humans have an enormous capacity for solving problems and behaving selflessly, so perhaps it’s not inevitable that biodiversity will continue to plummet. One of the main themes of this passage is if human beings aren’t conscious of the role they play in mass-extinction, they could go extinct themselves. Thus, for their own good, as well as for the good of the planet, humans need to find ways to preserve the ecosystem. Otherwise, the world’s rising sea levels and exponentially decreasing biodiversity could have serious ramifications for the human race. This relates to the APES theme that states that human survival depends on developing practices that will achieve sustainable systems. Humans need to end their destructive ways and try to reverse some of the current damage being done to the Earth and new systems and laws should be inputted into the world governments allowing for the human race and animals and the Earth itself to have longevity. United. In some cases some of the damage humans have done is irreversible. However, it may be possible for humans to change their behavior and preserve what remains of the world’s biodiversity. Education, government, and widespread of the word to the general public are quick ways for humans to take the next step into a better future. 
Me imagining what humans coming to a truce to stop hurting animals and their environments will look like. 

Thank you, Mr. Callahan; a very informative book that opened my mind to problems that aren't selfishly biased towards humans.

Chapter 12 : The Madness Gene (Angel Jorge)

In Chapter 12 of Elizabeth Kolbert's The Sixth Extinction, Kolbert introduces us to a small valley in Germany called Das Neandertal. She explains that here was where Neanderthal remains were first discovered. These sophisticated creatures were very smart to live around 30,000 years ago when they vanished. Kolbert argues that they were inbred with Homo sapiens (humans). Kolbert introduces a new field of science; paleogenetics. Under the right circumstances, it’s possible to examine prehistoric remains and find fragments of DNA. Kolbert meets a paleontologist in Leipzig named Svante Pääbo who is wishing to compare human and Neanderthal DNA. Kolbert soon speaks on the process of scientists over time separating the then-common belief that humans and Neanderthals were the same. Kolbert explains it in a way that makes humans seem demoralizing towards the Neanderthals even though it is highly likely that the humans were responsible for them to vanish. Kolbert explains the difficulty to reconstruct an entire genome from a few strands of ancient DNA. Therefore, paleogenetics is a slow, painstaking science, and a lot of work remains to be done before scientists reassemble the Neanderthal genome. Kolbert uses the rest of the chapter to analyze what makes humans...human. She states that ..."ambition and drive are vital components of human nature: unlike all other living creatures, humans feel a complex, irrational desire to discover the new. Perhaps it is this irrational desire that drives humans to hunt other species into extinction, permanently alter the environment, etc," (Page 247). This quote is Kolbert's main reason as to what makes humans unique and different from most species on the planet. Other than our destructive nature and fast reproducing, Kolbert explains the complexity of the human mind's natural ambition pushes it to make the harmful decisions that we make. This once again relates to the APES theme that humans alter natural systems. 

Chapter 11 : The Rhino Gets an Ultrasound (Angel Jorge)

In Chapter 11 of Elizabeth Kolbert's The Sixth Extinction, Kolbert takes the reader to Cincinnati where she meets with a Sumatran rhino, one of five left on the planet. She meets Dr. Roth (a conversationist who devoted her life to saving endangered species) and speaks about how Roth has had no success in artificially inseminating Suci (the rhino). Kolbert explains to the readers that rhinos were once very common throughout the world, but after the 20th century, rhinos began to go extinct. For the rest of the chapter, Kolbert fills in the middle of the timeline, trying to explain the role human beings played in the extinction of the rhinoceros. Kolbert blends together her personal experiences with Suci the rhino and her more abstract thoughts about extinction in general. This makes this chapter more empathetic because it gives the reader a sort of attachment to the Sumatran rhinos and makes this chapter more biased than her usual fact-based passages. "For most of the 19th century, scientists believed that large mammals went extinct because of the end of the last ice age, which reduced the evolutionary advantages of such traits as warm fur and large body mass. Only within the last few decades have scientists begun to suspect that large mammals went extinct because human beings hunted them," (Page 224-225). This quote shows how humans' slow thinking prevented them from understanding that they were the problem earlier. If they had understood their lasting impact on many other endangered species many of the now-extinct could have possibly been saved. the evidence Kolbert gives here suggests that it’s at least feasible that humans played a major role in the mass extinction of large prehistoric mammals. She is laying the groundwork here for a final opinion to the notion that humans are not inherently prone to irreversibly altering and destroying the world natural systems. The late chapters of The Sixth Extinction are based around the APES theme that humans alter natural systems.