JUST THE RIGHT SIZE

The pair behind such child-friendly explorations as Poop and What’s Eating You? (2004, 2007) deliver a similarly windily subtitled discussion of size in the animal kingdom. The pair begins by describing how the doubling of a creature’s length increases its surface area and cross-section (and therefore muscle power) by a factor of four and its weight and volume by a factor of eight—leading to such conclusions as, “That’s how ants can be stronger than humans!” They go on to explore how increasing the size of a creature necessitates increasing complexity, explaining how single-celled organisms can get by with osmosis but mammals require respiratory and digestive systems. The tongue-in-cheek tone, concrete examples and Layton’s undeniably appealing cartoons will go a long way with kids, as will the compact trim and one-topic-per-spread organization. But as a science book, it flirts with oversimplification. While evolution is mentioned multiple times, for instance, the concept of survival of the fittest is given short shrift, leaving unqualified such teleological assertions that gibbons attained their modern, house-cat size because “having a nice, light little body was very useful.” A shame. (Nonfiction. 8-12)