We Are All Africans Dr. Rasmus Grønfeldt Winther rgw@ucsc.edu ; www.rgwinther.com August 21, 2015 **Comments welcome. Not for further circulation.** 1. Narrative Imagine landing in the largest city, the capital, of an alien planet. You are stunned to see that every humanoid is within a few centimeters of the same height, everyone has a nearly identical muscular body, and everyone’s facial features are quite similar – high cheekbones, small noses, and black eyes. Perhaps most surprising to you, everyone has purple skin. The ambassador accompanying you tells you the purple skin is a consequence of interacting skin pigment proteins, the double-sun of that planetary system, and generation upon generation of voluntary random breeding. As you walk to your important meeting, the ambassador also informs you that every adult humanoid on the planet looks the same (Figure 1). Call this planet “Unity.” Figure 1. Imaginary inhabitants of Unity. Now recall Darwin’s natural experimental laboratory of evolution you learned about in high school biology, the Galápagos islands (Figure 2), and the wide variety of finch and tortoise species found there. Let us now populate them, in our minds, with identical small populations of early humans. Add a few more dozen islands that are larger, have distinct environments, and are distant and mutually incommunicable. Throw in a few million years of evolution. Humans on the islands of this thought experiment will come to be quite different indeed, in body, behavior, and culture. Call this scenario “Galápagos-writ-large.”