How the Snake Lost Its Legs by Lewis I. Held, Jr.

What follows when you select (upper left) are factual stories about how various animals acquired their quirky traits. These stories are excerpted from the new book How the Snake Lost Its Legs (Cambridge University Press, 2014).

The field of evo-devo (evolutionary developmental biology) has recently been solving age-old mysteries of animal evolution by providing genetic explanations. Key concepts from evo-devo are set in boldface and are defined in the glossary at the end of this presentation.

References have been omitted for clarity. Mammals are discussed first, followed by insects, and finally the snake. Many more animals are covered in the book.
leopard | leopard compared with butterfly | anglefish | zebra | mouse
cloud leopard | giraffe | ant | beetle | treehopper
stalk-eyed fly | ladybird | snake |

The Interactive Fly resides on the web server of the Society for Developmental Biology.