Food webs hold a central place in ecology. They describe which organisms feed on which others in natural habitats. This book describes recently discovered empirical regularities in real food webs: it proposes a novel theory unifying many of these regularities, as well as extensive empirical data. After a general introduction, reviewing the empirical and theoretical discoveries about food webs, the second portion of the book shows that community food webs obey several striking phenomenological regularities. Some of these unify, regardless of habitat. Others differentiate, showing that habitat...

Although universal schooling has been adopted as a goal by international organizations, bilateral aid agencies, national governments, and non-profit organizations, little sustained international attention has been devoted to the purposes or goals of universal education. What is universal primary and secondary education intended to accomplish? This book, which grew out of a project of the American Academy of Arts & Sciences, offers views from Asia, Africa, Europe, North America and South America on the purposes of universal education while considering diverse cultures, religions, and...