Planet Earth is shrinking at an ever-accelerating pace. It is not shrinking geologically, of course, or even atmospherically, unless you refer to the growing ozone hole. It is not even shrinking biologically in terms of net biomass, though some might argue that biodiversity is shrinking. But for Homo sapiens as a species, the planet is definitely shrinking. Why is this? Because, at least for now and the foreseeable future, planet Earth is our sole living space. The effective size of the available living space for any species is determined by the ability of that species to disperse throughout potential habitats, to successfully colonize those habitats, and to effectively utilize the resources available to them in those habitats. In terms of terrestrial habitats, since we are essentially a terrestrial species, we have pretty much dispersed to and colonized the entire planet. But we are an ingenious...

You do not currently have access to this content.