Where did humankind come from? If youre going to ask Zecharia Sitchin, be ready for a Planet of the Apes scenario: spaceships and hieroglyphics, genetic mutations and mutinous space aliens in gold mines. It sounds like science fiction, but Mr. Sitchin is sure this is how it all went down hundreds of thousands of years ago in Mesopotamia. Humans were genetically engineered by extraterrestrials, he said, pointing to ancient texts to prove it. [He] has spent his life arguing that people evolved with a little genetic intervention from ancient astronauts who came to Earth and needed laborers to mine gold to bring back to Nibiru, a planet we have yet to recognize. Mr. Sitchin has been called silly before by scientists, historians and archaeologists who dismiss his theories as pseudoscience and fault their underpinnings: his translations of ancient texts and his understanding of physics. And yet, he has a devoted following of readers. His 13 books, with names like Genesis Revisited and The Earth Chronicles, have sold millions of copies and been translated into 25 languages. Starting in childhood, he has studied ancient Hebrew, Akkadian and Sumerian, the language of the ancient Mesopotamians, who brought you geometry, astronomy, the chariot and the lunar calendar. And in the etchings of Sumerian pre-cuneiform script the oldest example of writing are stories of creation and the cosmos that most consider myth and allegory, but that Mr. Sitchin takes literally.