This is an interesting book to set alongside Armand Leroi’s remarkable book Mutants . As a pure reading experience, Mutants is without doubt streets ahead. Leroi’s style is much more readable and engaging, where Blumberg tends to the pompous and resorts to academic pronouncement. However he does have a good criticism of the dependence of Mutants on a genetic basis for unusual physical formation in animals and humans. After all, as Blumberg points out, human beings have produced quite dramatic variants through environmental pressures – head and foot binding, for instance. Development is as important to the production of freaks of nature as is the genetic material and its flaws. That said, Mutants is, not surprisingly, about, well, mutants – so it’s hardly surprising that this is the main thrust of Leroi’s story. But the distinction does give Blumberg a broader canvas to work with. Perhaps the most interesting aspect of the book is Blumberg’s stress on the way animals develop o