"The Sixth Extinction" Chapter 2

Before the seventeenth and eighteenth centuries, many people did not have the knowledge that there had once been a world without people, where other species lived. The majority of the time that biologists and paleontologists would study animals, they assumed that the bones belonged to a species that continued to roam the Earth at that time. The concept of extinction emerged because of the discovery of bones that belonged to an American mastodon. Initially, people believed that the animal was an animals; however, the finding could not be categorized because instead of the teeth being “flat on top, with thin ridges,” the Mastodon teeth were “cusped.” (Kolbert, 24) This commenced great controversy between various scientists because many believed that it was either an elephant, another animal, or bones that belonged to different species of animals.



The controversy was ongoing was up until Georges Cuvier, a French naturalist, studied the Mastodon teeth and believed that this species was no longer roaming South America. At this point, there had been four discovered extinct species; to Cuvier, this meant that there were many more extinct animals out there that had not been found yet. Therefore, he set out to find the many others to prove the concept of extinction by finding more physical evidence. By doing so, Cuvier later discovered more extinct creatures such as: the pterodactyl, an ichthyosaur, among tens of others. However, it is notable that France would tend to not send out actual fossils, only detailed drawings to Cuvier. This may cause many people to wonder: Are there any fossils out there that countries are hiding from the United States that consists of an undiscovered extinct species?



Because Cuvier was able to uncover a plethora of extinct species, he was able to prove the concept of extinction. Now, he set out to find out the reasons that species would become extinct, which aroused another debate between scientists at that time. For example, Jean-Baptiste Lamarck still disapproved of Cuvier’s theory of extinction because “there was no process he could imagine capable of wiping an organism out entirely.” (Kolbert, 42) To Lamarck, those extinct” species merely transformed and evolved, which explains why they were no longer found living on Earth. Unsurprisingly, Cuvier immediately responded by claiming that the American Mastodon was wiped out by a catastrophe. Later scientists would prove that the statement Cuvier made about a catastrophe was true.





The accomplishment of Cuvier in proving the concept of extinction demonstrates the theme that “science is a process.” In the beginning, people only had the understanding that there were no species before humans because fossils had not been correctly identified as species that were no longer roaming the land. However, this was proven false with the discovery of fossils and scientists classifying them as extinct species that lived thousands of years prior to human existence. This parallels the diagram on the left because it demonstrates how humans are the most “recent” species that has lived on Earth, thus proving that there were millions of species before humans. In the discussion of this diagram, the PhD students stated that “humans are not the pinnacle of evolution” since many things can happen over the course of thousands of years. Now a worrying question remains: What other species would become extinct because of climate change and human interference?