''Shermer is savage about the shortcomings of intelligent design and eloquent about the spirituality of science . . . An invaluable primer.''--''Los Angeles Times Book Review'''''' Science is on the defensive. Half of Americans reject the theory of evolution and intelligent-design campaigns are gaining ground. Classroom by classroom, creationism is overthrowing biology. In ''Why Darwin Matters,'' bestselling author Michael Shermer decodes the scientific evidence to show that evolution is not ''just a theory'' and illustrates how it achieves the design of life through the bottom-up process of natural selection. Shermer, once an evangelical Christian and a creationist, argues that intelligent-design proponents are invoking a combination of bad science, political antipathy, and flawed theology. He refutes their pseudoscientific arguments and then demonstrates why conservatives and people of faith can and should embrace evolution. Cutting the politics away from the facts, ''Why Darwin Matters'' is an incisive examination of what is at stake in the debate over evolution.