How the Snake Lost Its Legs fly embryo. His books on evolutionary developmental biology (evo-devo) include "Imaginal Discs: The Genetic and Cellular Logic of Pattern Formation" (2002), "Quirks of Human Anatomy: An Evo-Devo Look at the Human Body" (2009), and "Deep Homology? Uncanny Similarities of Humans and Flies Uncovered by Evo-Devo" (2017). In Held's view, "Quirks", "Snake", and "Deep Homology" form a trilogy on evo-devo. "How the Snake Lost Its Legs" is ostensibly organised into six chapters, but in effect into three parts. The first chapter serves as an introduction and overview. The next four chapters provide what Held calls "the meatier aspects of evo-devo" with
Butterfly Koi – The ratio of fin-to-body is an important scoring criteria in nishikigoi competitions. By design, longfin embody a ratio that exceeds the standards applied to nishikigoi by 500 to 1000 percent. Pattern differences - Great energy has been given to developing butterfly koi versions of traditional koi patterns, (e.g. kohaku, sanke, showa, utsuri and ogon). Butterfly koi, however, exhibit these patterns in a slightly different way. For these reasons, Japan's Zen Nippon Airinkai ZNA (an organization that sanctions Japanese nishikigoi hobbyist competitions) have disallowed butterfly koi from competitive judging for many years; the UK Koi Judges Association also excludes these