Paul Andersen discusses scientific evidence of the origin of life on our planet. He begins with a brief discussion of the age of the earth and ends with the future of humanity. He includes geologic, chemical and molecular data.

Paul Andersen describes how life could have formed on our planet through natural processes. The progression from monomers, to polymers, to protocells and finally to cells is described. The Miller-Urey experiment is described in detail as well as characteristics of the latest universal ancestor.

Paul Andersen details the evolutionary processes of speciation and extinction. Stickleback evolution in Lake Loberg is used as example of rapid speciation. Adaptive radiation is illustrated using the Hawaiian honeycreeper. A brief discussion of extinctions and mass extinctions is also included.

Crash Course Biology #17 - Hank introduces us to the relatively new field of evolutionary developmental biology, which compares the developmental processes of different organisms to determine their ancestral relationship, and to discover how those processes evolved. Also fruit flies with eyes on their legs and chickens with teeth!