How the Snake Lost Its Legs the butterfly, the snake, and the cheetah. Each consists of three to eight sections named in the style of Rudyard Kipling's "Just So Stories", with titles like "How the butterfly got its spots" or "How the snake elongated its body", though a couple of sections use "Why?" rather than "How?", as in "Why the fly twirls his penis" (it rotates during embryonic development under the control of different genes). In these chapters, Held explains the mechanics of evolutionary developmental biology, complete with accounts of what genes such as hox, hedgehog, and engrailed do to shape bodies. The third part is
Leopard complex progressive roaning that is unrelated to graying out or true roan. Horses with coat patterns within the leopard complex are known for their mystifying coat changes. This unusual characteristic is due at least in part to leopard roaning, also called "varnish roaning." While the gray gene only affects the hair, some horses with the "Lp" gene will progressively lose pigment in both the skin and hair as they age. Also unlike graying out, the leopard spots are not affected by this roaning process. Neither are the "bony prominences" strongly affected. As a varnish roan horse lightens, the leopard spots indistinguishable