Charlie Stross asks How habitable is the Earth?: "We H. Sapiens Sapiens appear to be an infestation on this planet. After the slow-burning evolution of hominins in Africa, our ancestral populations erupted out into Eurasia in a geological eye-blink, spread into the Americas by way of the Bering land bridge (sea levels being somewhat lower during the ice ages) and finally reaching even the remotest islands of oceania around twelve thousand years ago. Today we're ubiquitous. Even our pre-industrial ancestral cultures, from those resembling the inuit to the antecedents of the tuareg, occupied a slew of geographical environments that put cockroaches to shame."