The Sixth Extinction: Chapter 10

     In Chapter 10, a team of biologists find dead bats in a white fungus called Geomyces destructans. Darwin’s ideas are helpful to understanding the bat die-off, since he argued that most animals can’t travel long distances, hence the bats died. The idea of natural selection concludes the existence of isolated environments with natural barriers like mountains, oceans, rivers, and etc. The problem with his assumption is that many animals are capable of traveling long distances over natural barriers. In the Anthropocene, animals were dispersed around the world because of humans. But when a species encounters a new environment, two things can happen: 1) nothing; 2) the new environment kills the species. Most of the time, a species can’t adapt to a new environment. But when a species does so, it reproduces and may sometimes spread to other surrounding environments. Kolbert meets with Al Hicks, one of the scientists who had discovered the dead bats in Albany, and they both go to the Adirondacks, the mountains where his team was conducting environmental tests. Hicks concludes brown bats as another species dying because of the fungus. The study of invasive species began with Charles Elton where he compared the movement of species to the exchange of gases in a set of tanks. He concluded that if closed-off tanks of different gases were suddenly allowed to intermingle, the previously isolated gases would combine into new chemicals. In the short-term, there would be a lot of molecular movement. Eventually, however, the gases would reach a new equilibrium, in which there was less molecular variety. Following Elton’s analogy, in the future, the New Pangaea will reach a new equilibrium, but it will probably have fewer species than now. Kolbert concludes that if human commerce ceases, biodiversity will begin to grow again.

     The theme that most resonated with this chapter is humans alter natural systems. In the book it states, “What Boiga irregularis has done in Guam, he observes, is precisely what homo sapiens has done all over the planet: succeeded extravagantly at the expense of other species.” (Pg. 204) (R) Through the introduction of invasive species humans have altered many systems on the Earth. The invasive species that are bad for the environment are usually non-native invasive species since they decrease native biodiversity. They colonize habitats, and exclude the native plants and animals. In their new ecosystems, invasive species become predators, competitors, parasites, hybridizers, and diseases of our native and domesticated plants and animals. The invasive species messes with the already existing paradigms of the native species and causes them to fight for survival of the fittest. However the invasive species is also impacted, since they also have to adapt to another habitat. Humans have brought different species in order to help them in eradicating other species, but then they become the bigger problem. As humans move around the globe, more non-native species are turning up in these harsh habitats, some from similar habitats in other parts of the world. Humans use different things like manual removal, pesticides, and biological controls, but it only impacts the environment because of its “violent” ways or chemical poisoning.

By: Mousumi Dhar