No other species is recognized with its own interval of geologic time. Why did humans, alone among species, gain the capacity to transform an entire planet? When did this capacity emerge—and by what mechanism? Are all humans equally a part of this transformation? What evidence is needed to answer such questions? More broadly, what does it mean to be human when this means to be part of a global force that changes everything—even the future of an entire planet? What does nature even mean in an age of humans?
