"The Sixth Extinction" Chapter 5- Matthew Batista

A pair of Harvard psychologists performed an experiment about whether or not information that didn't fit commonly explained assumptions would be discounted or explained away. The results were that the more contradictions accumulated, the more convoluted the rationalizations became, leading to the term "paradigm shifts"(93). After this Kolbert talks about how she is being guided to Dob's Linn to see observe a cliff formed after the Cambrian explosion and before the Ordovician period. After the Ordovician period about 80% of marine life died. Some creatures called graptolites left fossils which Kolbert and her guide were observing. 

Kolbert uses the extinction of graptolites and other clades to explain glaciation as a mechanism for extinction. She continues by expressing that when carbon dioxide levels in the air are high, there typically is accompanying increases in temperatures and seal level. Kolbert states, “Sea levels plummeted, and many marine habitats were eliminated, presumably to the detriment of marine organisms”(103). Connecting back to graptolites, right around the time graptolites became extinct, carbon dioxide levels dropped. Temperatures fell and sea levels dropped. This caused a change in the chemistry of the ocean, which had a devastating impact on the life forms. When thinking about this my mind goes straight to greenhouse gases. Greenhouse gases are good; however, connecting to the theme “humans alter natural systems,” humans are releasing more greenhouse gases than we need into the atmosphere. The Ordovician period occur naturally but right now we are seeing similar changes in the temperature. Humans are altering the temperature because of factories and the new technology that we have. It’s easy to see how we are in “The Sixth Extinction” and if we continue on this path it will come to no ones surprise when many species are extinct. We need to learn from the past and understand that we are changing our environment too hastily and it will get to the point where there is no return. We are the generation of change and we need to do something now before the next generation won’t be able to experience the animal kingdom.