Wilson uses the term “alien” several times to describe invasive species and humans. This is a distinct choice to show the otherness of species that do not belong to certain ecosystems. The take-over by these alien species “is not a Hollywood script” (15). They do real damage to environments by outcompeting and ultimately extinguishing the native species. Because these species are alien to the area, they will not provide balance to an ecosystem as its local native species go extinct. Like these invasive species, Wilson believes that “people fell upon the planet like a hostile race of aliens” (72). This passage is clearly not a compliment towards our species. Earth is our home, and we are members of its biosphere, yet we act like alien invaders who care nothing for the planet they are conquering. The term reinforces our destructive activities towards nature and the reality that if we do not end these habits, we will destroy our home and our future within a short geological span.

Wilson repeatedly uses the term “champion” to describe surviving species, including humans. His logic is that each surviving species has overcome the challenges that evolution by natural selection has thrown its way. The environment is always changing, and species must be able to navigate these changes and successfully reproduce.