Life

Life is notoriously hard to define. Most biologists would agree that a living organism is one that maintains a complex, low-entropy structure (its body) in a state of persistent chemical disequilibrium, by taking in energy and nutrients and excreting high-entropy waste products. All of these traits apply to Gaia except that the nutrients she uses are cycled continuously through her body, converted to "waste" and then back to useful substances using the continuous influx of energy from the Sun.

Reproduction is also an essential aspect of Life, but of course a sterile organism can still be alive (although a species is considered "ecologically dead" if none of its members can reproduce). For details on how Gaia might reproduce, see Gaia's Children and Ecopoeisis.

Evolution is another essential aspect of Life. The Gaia Hypothesis leads to fascinating insights about evolutionary theory, which previously didn't take into account the possibility that living beings could adapt their environment to suit themselves rather than the other way around.