Chapter 5:

The chapter starts with the experiment that helped develop science historian Thomas Kuhn’s ideas of human adaptability. The experiment, performed by psychologist at Harvard, had some undergraduates shown some playing cards and guess them. Some of the cards were doctored and so when the students were shown all their cards and realized their mistakes they performed better. This made way to Kuhn’s theory of how humans survived called the “Paradigm”. We learn new strategies from our mistakes and survive better in new environments. This is a great example of evolution. Kolbert visits a cliff called, “Dob’s Inn”to meet with stratigrapher Jan Zalasiewicz about his specialty in graptolite. Graptolite was a marine animal who used to be very common. They would attach themselves to each other to form a single graptolite. They had long and V shaped bodies which served them as a tool against changes in water pressure and temperature. Sadly, their bodies later on served as a disadvantage. A theory came out about what made them and other species extinct. Scientists think a glaciation led to their demise because as the carbon dioxide levels decreased so did the temperature of the ocean. Scientist found out that mossy plants during the Ordovician era were taking in carbon dioxide which in turn helped killed the marine life. Scientists believe that humans have changed their environment in many ways. Some examples are humans ruining oceans, rivers, land, consuming almost all freshwater, running the atmosphere by releasing carbon dioxide and methane, and having agriculture realize a lot of nitrogen. Paul Crutzen named the effects on ozone-depleting compounds, “ Anthropocene”. The effects have left a hole in the ozone layer of the atmosphere which is slowly heating up the environment which is now called  global warming. Cruzen, in his short essay “ Geology of Mankind”, wrote, “ the global climate is most likely to ‘depart significantly from natural behavior for many millennia to come” (pg 108). This hole will lead to changes that we might not be able to fix and in turn lead to another mass extinction. Humans have altered their environment tremendously over the millions of years that we've been here. however, in my opinion, we can solve this ongoing issue of global warming with the new technological advancements that we now have. for example, people are using renewable energy, such as solar panels, in effort to end the use of fossil fuels. With time, humans can fix what we've broken.