What does it mean to be fully human? Evidence suggests that the mastery of fire most likely predates homo sapiens, as does the use of stone tools. Is it the ability to engage in symbolic activity such as language? And why is homo sapiens the “only representative of its group [genus homo] in the world today”? In “The Rickety Cossack,” Ian Tattersall, a paleoanthropologist (or “student of human evolution”) at the American Museum of Natural History in New York, offers his readers an exciting and cautionary history of how scientists have worked to explain the development and success of our species.

The study of human origins is a very new field. Darwin’s “Descent of Man” (1871) extended his earlier ideas about flora and fauna, but included little discussion of evidence. As Tattersall says, “The human fossil record was a place Darwin just didn’t want to go.” The following decades, however, were the Golden Age of fossil hunters, and Tattersall recounts the thrilling sense of quest — jaws, skulls, entire skeletons that resembled our own to varying degrees. Yet there was no agreed-upon scientific method by which to examine and place the findings. To complicate matters, each discoverer would claim that the finding was an entirely new species and that each of these was “the missing link” between man and ape.

Tattersall cites his late colleague Stephen Jay Gould, who observed that “we are all unconscious victims of our preconceptions,” and paleoanthropologists, as we come to know them, are all too human. They stake out excavation areas, refuse to share evidence and make inflated claims for their finds. Authoritative pronouncement takes the place of disinterested reasoning. Salesmanship — necessary in securing funding and access to lab facilities — seems to replace systematic scientific method. Perhaps this is to be expected in a new science.

The bigger issues of the book, however, concern how early hominids lived: The author asks good questions, and his intelligent speculations about human origins make this a very lively book. Why did proto-humans begin to walk on two legs? Why did our species develop such enlarged brains? What was the relationship between Neanderthals (with even bigger brains) and homo sapiens? The two species coexisted on Earth for at least 300,000 years. Why did the Neanderthals die out — or continue to exist in our gene pools today?

Tattersall rejects the notion of a single linear evolution of man. The extreme diversity of the fossil remains he describes makes it hard to envision a single chain of links culminating in our species. “We are,” he concludes, “the pinnacle of nothing. Instead, we are simply one more twig on what was until very recently a luxuriantly evolutionary tree.”

A lucid and provocative work, “The Rickety Cossack” challenged my imagination on every page.

 

Tom Zelman teaches English at the College of St. Scholastica in Duluth.