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
How Many Licks? song as an example of how Sisqó pushed the envelope of sexuality in popular culture. Brittany Vincent of "Billboard" noted it as an example of how the rapper was unafraid of exploring sex in her music. An editor for Apple Music included the song on its "Lil' Kim Essentials" playlist, writing that Lil Kim' "more than held her own as an agile and self-possessed MC who pushed hip-hop toward its unalloyed id". However, African-American studies professor Mark Anthony Neal criticized the single for perpetuating the sexual objectification of women. Comparing "How Many Licks?" with American singer Tweet's 2002 song "Oops