In Chapter 5, Kolbert introduces us to Thomas Kuhn, who believed that throughout history, human beings are forced to adapt to changing environments and that they learn new paradigms in order to survive. His ideas on paradigms and paradigm shifts help scientists study evolutionary science. For example, Walter Alvarez’s theory created the new paradigm of mass extinction. Following his theory, scientists started to focus on fossil gaps because they theorized that if an asteroid caused one fossil gap, then other catastrophes could cause other fossil gaps. Although, scientists haven’t proven it with evidence, the Alvarez theory and the scientists’ paradigm on catastrophes gives proof that at the end of the Ordovician era, glaciation killed many species. Kolbert then travels to a cliff called Dob’s Linn and meets with stratigrapher Jan Zalasiewicz. Kolbert learns about graptolites and how their V-shaped bodies became an evolutionary disadvantage and caused them to go extinct. She also learns about Zalasiewicz’s theory on giant rats. She claims that rats are the most strongest creatures on the planet and if there’s an event of mass extinction, the rats will probably survive. She also claims that humans lead the new era of mass extinction. Paul Crutzen agrees with her and gives five points, saying that the humans have brought the Earth into the Anthropocene era. Crutzen also argued that the result of these manmade changes in the environment will be a new mass-extinction.
The themes that resonated with the chapter is humans alter natural systems and human survival depends on developing practices that will achieve sustainable systems. At the end of the chapter Paul Crutzen said, “We are no longer in the Holocene; we are in the Anthropocene...It seems appropriate to assign the the term… to the present, in many human dominated, geological epoch…” (Pg. 108) He then listed changes that humans made which include: 1) humans have transformed almost half of the world’s land surface; 2) humans have either damned/diverted the majority of the world’s rivers; 3) human agriculture has increased the amount of nitrogen in the atmosphere; 4) humans have eliminated more than a third of the primary marine life of oceans’ coastal waters; 5) humans consume more than half of the world’s available fresh water; 6) humans have dramatically changed the composition of the Earth’s atmosphere by releasing carbon dioxide and methane gas. (R) As humans have continued to create paradigms to adapt to their environment they don’t realize that they’re causing the deterioration of the environment through depletion of resources such as air, water and soil; the destruction of ecosystems; habitat destruction; the extinction of wildlife; and pollution. And as this continues, it’ll only impact them, because the Earth is an interconnected system, and without food supply from food chain and resources in order to evolve, humans can go into mass extinction.
By: Mousumi Dhar
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