Scientist and “Lucy” discoverer Donald C. Johanson will talk about his atheism, evolution and how he feels about “Ardi” displacing “Lucy.” FFRF’er John Whiteside will talk about why he underwrote a billboard blitz in Las Vegas for the Foundation, featuring 10 billboards variously reading: “Imagine No Religion,” “Beware of Dogma” and “Praise Darwin: Evolve Beyond Belief.”