I can introduce the body of this course only by describing one of my favorite places.  Occasionally, I have the opportunity to return to the Guadalupe Mountains in west Texas.  Among my hikes there, I always include a climb up into the "Bowl", home to a relict forest from the last glacial period.  The retreat of the glaciers marooned northern species atop southwestern desert mountains such as Texas' Guadalupes and Chisos.  I always stop for lunch at Hunter Peak which juts up along the eastern escarpment of this enormous, uplifted coral bed that we now call a mountain range.  There, with claret cup cacti wedged into the rocks, I'm invariably joined by white-throated swifts which course up and down the mountain's east-facing canyons as they sweep for insects.  Over and over, they hurtle by and down, often so close that the air flow through their feathers offers a musical accompaniment to lunch.  How did these fabulous feeding machines come to be?  How is it that a mountain of coral rises out of the desert?  How has life managed to wedge itself into every crack in this, and other, harsh environments?  These are the subjects of our introduction to evolution.  All that we observe as biologists is part of a large tapestry with evolutionary theory as its unifying thread; by the end of this course, your ventures in Biology--every trip outdoors and in the laboratory--will be seen with the new eyes that a knowledge of evolutionary theory provides.