"Language is what makes us human. Maybe it's the only thing that makes us human," asserts Hawai'i linguist Derek Bickerton in his new book "Adam's Tongue."

Professor emeritus of linguistics at the University of Hawai'i and author of "Bastard Tongues," an exploration of pidgin and creole languages, Bickerton writes on the topic with confidence. Reading "Adam's Tongue" is like stepping back into the classroom of a quirky, vibrant, impassioned thinker engaging in a most perplexing problem: How did language arise, and which came first: language or complex thought?

Central to Bickerton's theory is that both the human-centric research approach, which deems humans superior beings, and the primate-centric view, holding that we only need look to primates for answers to language origin, are red herrings, erroneously placing humans at the center of evolution study.

Instead, Bickerton's foundation is "niche construction theory" (species evolve by adapting their environment to their use), and this and other complicated topics — such as apes' ability to "talk," communication systems of bees and ants (our closest linguistic cousins, he says) and the way scavenging habits may have opened the door to protolanguages — are simplified just enough for the lay person to grasp.

First Bickerton sets out the groundwork for his theory. Then he's off — acting as his own devil's advocate, laying out counterpoints and refuting them, impaling his previous assumptions and those of well-known behaviorists, biologists, religions and nonreligions like intelligent design, and other linguists, including part of Noam Chomsky's standpoint on language evolution, because Bickerton boldly claims that "on the subject of how language evolved, if on nothing else, (Chomsky is) completely wrong."

At the same time, Bickerton continually evokes visual scenarios to help us imagine the world of early humans, building suspense by ending chapters with a cliffhanger, as if to keep us coming back to next week's lecture.

His tone remains conversational, asking the reader to remember caveats and keep points in mind for later, noting when he's digressing and always exercising complete control over material. The ride through serious debates and scientific issues is lightning-quick and informal, though supported with extensive notes and research. He takes us through early history of language, always having fun, employing humor, metaphors and stories, speaking with the joy of his life's work in his trademark provocative style.

Only during his final point, his belief that "language came first and enabled human thinking," does the book get a bit dense and technical.