When the paradigm shift was discovered, it claimed that when humans encounter new situations, they respond with similar strategies; gradually, however, humans develop a new framework to fit the situation. This concept correlates with the way scientists have approached extinction: when a new idea is introduced, scientists adapt and change their theories. For example, when mastodon bones were unearthed, scientists thought they belonged to an elephant or hippo; however, Cuvier realized that the bones did not align and proposed that the bones belonged to a new species.
When Kolbert visits Dob’s Linns, Jan Zalasiewicz showed her rock layers from the Ordovician era; at the beginning of this era, sea-life and coral reefs grew. However at the end of the era, almost all ocean life went extinct; one such example is the graptolite, a marine animal, with V-shaped bodies. Unfortunately, these features became a disadvantage, proving Darwin’s ideas about natural selection and evolution.
After the Alvarez's discovery, scientists argued that there had been many other mass-extinctions in the past; for example, the Ordovician extinction, the 2nd mass extinction, was said to have been caused by excess plant consumption of carbon dioxide. Thus, carbon dioxide in the air increased and the oxygen in the water decreased, causing 90% of the world's species to go extinct. One key passage that stood out to me was, “every extinction event appears to be unhappy and fatally so in its own way...those of us who were working on this naively expected that we would go out and find evidence of impacts coinciding with the other events…” This confused me because at what point do we know another extinction event is occurring. Are all mass extinctions detected in fossil records? And how do you identify how much time has passed in the event?
Overall, science allows for continued knowledge and understanding. Through discovering other mass-extinctions, it is evident that every event is different; in that case, mass extinctions are defined by what happened to the biota and species at the time. Moreover, although the present seems to be full of technological advancements, it should still be considered a mass extinction.
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