The Sixth Extinction: Chapter 4

Chapter Four explores the mass extinction that ended the time of the dinosaurs. This all began in Gubbio, Italy were Walter Alverz discovered a layer of clay containing no fossil Luis Alvarez suggested that he should test the clay’s radioactivity to trace its origin and time. The clay traces to an asteroid that scientists concluded to cause the mass-extinction of dinosaurs. Despite the rejection of this theory by many scientists, more and more evidence began to build up that ultimately proved this theory of mass extinction to be correct. This includes the discovery of the crater in Mexico, where an asteroid potentially impacted the planet. Now that the Alvarez had proof of the asteroid hitting the planet they theorized that the impact wasn’t what led to the great extinction, instead it was the dust that released into the air that was so hot that it killed off most species. Although most of life on earth came to an end, some species kept living because of the concept of “preservation potential” which measures the likelihood of extinction through the species population, location, and traits. One of the multiple species that survived the great extinction where Ammonites because of their traits of protection. Although the species survived the asteroid, the population of the species still suffered a terrible loss but the fact that it inhabited several areas of the planet potentially saved it from extinction. Along its side multiple other species also survived extinction and they affect the planet's ecosystem today meaning that most of today's species are interconnected through a complex web that possibly reveals in commonality of ancestors. At the end of this chapter, I was left thinking about the different ways that species need to adapt to survive. I wonder if it’s possible for species to adapt ahead of time in order to survive future catastrophes?

This chapter connects to the theme that science is a process since it shows the development of scientific ideas throughout time to land at a conclusion. "The Alvarezes batted around theories. But all the ones they could think of either didn’t fit the available data or were ruled out by further tests. Then, finally, after almost a year’s worth of dead ends they arrived at the impact hypothesis" (Kolbert 75) This shows how science takes time and patience but most importantly it takes resilience because everything we think we know can always change.