Title: Biodiversity.
Question: Who commissioned the biodiversity research paper?

Title: Planck constant.
Question: Einstein and what other two individuals revisited the black-body problem in 1905?

Title: Hellenistic period.
Question: Who succeeded or ruled alongside Apollodotus I?

Title: John von Neumann.
Question:
What type of "off color" humor did Von Neumann especially enjoy?