Leaps in learning

These two university-level textbooks on developmental biology adopt contrasting styles and have different aims.

Principles of Developmental Biology signals its intent in the title: it aims to provide "an introduction to developmental biology that presents the essentials without overwhelming students", with either length or difficulty. In this it succeeds, presenting in 18 concise and well-written chapters of about 20 pages each a pleasing introduction to the field, suitable for a one-term introductory course. It uses simple smart colour illustrations and few photographs. Details of the molecular basis of development are invoked only where necessary.

It is up to date, as evidenced, for example, by the sub-section on "Conservation of genes and networks", the latter topic - gene networks - of great importance. The book is not encumbered with a CD-Rom or packets of slides for teachers. I say "encumbered" because for an introductory one-term course, these materials can be daunting to students, who often worry that all available reading materials may be drawn on for exam questions. In place of electronic materials, the authors offer key concepts and study questions at the end of chapters.

Developmental Biology is a book for majors, designed to give students a broad knowledge, and to prepare them for more advanced courses in development, embryology, cell signalling and evolutionary-developmental biology. It aims for encyclopaedic coverage, at least at undergraduate level. In this it largely succeeds, even if it is not always succinct. But the material is carefully chosen, relevant and densely illustrated in colour.

Students will find thought-provoking the "Sidelights and Speculations" sections in each chapter. These present case studies on, for example, genetic assimilation and deformed frogs. The book comes with a CD-Rom and there is a dedicated website.

These are the elements of the North American "package" approach to pedagogy, developed for the large class sizes of many courses in the US. Large class sizes are beginning to be seen in the UK and will eventually call for teaching packages following the North American model.

Mark Pagel is professor of evolutionary biology, University of Reading.