We live in a post-Darwinian world, and it is no longer possible to conceive of life without some reference to Darwin's theories. But the world is more complex than Darwin supposed. Whereas an evolutionary perspective pervades all of biology, economics and politics, we are confronted by a range of post-Darwinian complexities and challenges that require a new and expanded set of ideas. Five short presentations by SFI faculty explore both the influence and the limitations of Darwin's thought on modern science, and introduce several of the ways the Santa Fe Institute has responded to and built upon Darwin's legacy.