Britain's Guardian is gearing up for the 150th anniversary of Charles Darwin's theory of natural selection tomorrow with a guide to On the Origin of Species, including chapter extracts, as well as essays from Richard Dawkins, Richard Harries, and Laurence Hurst. The excerpts discuss where new species come from, the driving force behind evolution, and why the fossil record has gaps. The essays look into science and faith, genomics, why Darwin does matter. "Darwin emboldens us -- difficult as it is -- to seek genuine explanations: explanations that explain more than they postulate," writes Dawkins.