The Beasties We Need Near Us

From New Scientist:

• As humans became urban and industrial, we also separated ourselves from other species. Pets aside, we have laboured to rid our houses and cities of creatures - not just visible predators and pests but also the microbes on our countertops and hands. Some of these steps were sensible acts of self-preservation, but others were driven by an ideology of humans as separate from nature. Dunn, a biologist at North Carolina State University as well as a science journalist, catalogues the dangers of that ideology.
  
  To illustrate how species influence one another's evolution, he points to the pronghorn, a small antelope-like mammal in North America that runs inexplicably fast. The pronghorn's speed, Dunn says, only makes sense if you consider the large predators that once hunted it. The "pronghorn principle" also applies to the human body. We too are "haunted by ghosts" of parasites, pathogens and predators that shaped our evolution.

One for the reading list methinks: "The Wild Life of Our Bodies" By Robb Dunn