I'd avoid it because it is a rather misleading book whether or not it is accessible. Many people (but especially Carl Woese) led to our modern understanding of molecular phylogeny. Lane's main contact for his book was Bill Martin, who was a rival to Woese, which is fine, but the result is a story in which Martin made all the major discoveries and Woese literally gets one sentence. I'd strongly recommend Quammen's "The Tangled Tree" instead, which is a more balanced book.