Pick up your favorite geology book and likely you can read about the "Age of Fishes", the "Age of Reptiles", and the "Age of Mammals". This all goes to show that we really are a rather self-centered group. You'll note that all of these happened to be back-boned creatures—vertebrates, like us. Where are the plants? After all, it's the plants that allow us vertebrates to exist and who, on land, form the most noticeable feature of the living landscape. Or where are the insects, out-numbering the back-boned creatures many times over? Even more pertinent, why aren't all these "ages" rolled into one—the "Age of Bacteria"?
Not only are these the most dominant life forms on earth, but they have
been for several billion years. There probably is not an acre of ground in the
Chihuahuan Desert that doesn't harbor more bacteria than all the more complex
organisms in the world put together. Even the living body of the average person
contains more bacteria than the human population of earth. Gives you something to think
about, doesn't it?
Contributor: Arthur H. Harris, Laboratory for Environmental Biology, Centennial Museum, University of Texas at El Paso.
Desert Diary is a joint production of the Centennial Museum and KTEP National Public Radio at the University of Texas at El Paso.