American Scientist

What It Means To Be 98% Chimpanzee: Apes, People, and Their Genes. Jonathan Marks. xiv + 312 pp. University of California Press, 2002. $27.50.

No single discovery in molecular anthropology has been invested with greater significance than the recognition that humans and chimpanzees are about 98 percent genetically identical. This remarkable proximity may have led many to imagine that the technologies of molecular genetics have delivered a deep understanding of humanity's place in nature. If so, then they have committed what Jonathan Marks, in What It Means to Be 98% Chimpanzee, terms "the central fallacy of molecular anthropology."

This error, according to Marks, turns on the belief that the dramatic expansion of genetic knowledge over the past 25 years has contributed greatly to our knowing what makes us differ in the most important ways from apes. Marks argues that the differences and congruencies identifiable at the genetic level have scarcely anything to do with observable patterns in morphology and behavior. As it happens, genetic data reveal little more than phylogenetic relationships, and no amount of DNA sequencing can tell us what makes us human and apes not.

This book, then, is a trenchant assault on genetic reductionism and a spirited call for a more critical science, one better informed by the perspectives of anthropology and the humanities. The author, himself an accomplished anthropological geneticist, seeks to frame the limits of what we can expect to learn about ourselves from molecular genetics, and the limits we ought to deploy in our search.

Marks has a big story to tell, one ranging considerably beyond the Pan-Homo connection of the title. He is especially interested in examining how ideology and science inevitably intersect, most strikingly in the arena of human variation and behavior. Thus he detours along the way to inspect the eugenics movement of the early 20th century, the rapid shift in the scientific view of race precipitated by the Second World War (and in the United States by the subsequent emergence of the civil rights movement), the recent political battlefield of the misbegotten Human Genome Diversity Project, the courtroom battles pitting anthropologists against Native Americans over possession of the remains of Kennewick Man, and other prominent landmarks evincing in one way or another the confounding of science and ideology. Within this narrative (the case of Kennewick Man being an exception), Marks has benighted geneticists typically bearing responsibility for misprisions, and corrective views emanating from anthropologists. My own strong sense, however much I'd like to keep my white hat as an anthropologist, is that this bias will not hold up to close scrutiny.

One might reasonably read Marks's frequent admonitions that we learn from past failures as an enjoinder to root out ideology from scientific practice, or at least to become more cognizant of it. After all, did not the egregiously overreaching claims of the eugenicists reflect the racial and class prejudices of their Euro-American Weltanschauungen? Similarly, because Marks situates currently prevalent scientific misconceptions about ourselves in a matrix of persistent folk models of heredity (sociobiology and its child, evolutionary psychology, receive expectably rough treatment here), his critique might invite us to conclude that ideology continues to compromise scientific inquiry. But Marks seems not to see matters quite this way—and herein lies what I see as an unresolved problem in his view of science: his acceptance that ideology should sometimes color science.

Indeed, Marks is hardly disquieted about the introduction of extrascientific ideas into an enterprise long and wrongly held to be value-neutral. He notes approvingly that the demise of the Human Genome Diversity Project had much to do with its failure to justify itself to the subjects whose blood it proposed to draw. The principal goal of the project, a reconstruction of modern human origins from an examination of global genomic patterning, too often contradicted the targeted participants' views of their own histories; their resistance to participation derived partly from unwillingness to cede their interpretive authority. Likewise, the story of the recent Kennewick Man debacle is framed by the refusal of the Umatilla people to subordinate their own origin account to that of anthropologists. In a consistent vein, Marks even expresses regret for the threatened cosmology of Christians who embrace biblical accounts of creation as literally true (although his own evolutionary research has itself contributed to this threat).

All of this would suggest that, in perceiving the inherent embeddedness of ideology in scientific practice, Marks is advocating the negotiation of contending claims among all concerned parties. He may favor such a dialectic as far as negotiating access to human genetic data goes, but there is another direction that he is headed, evident in what at first seems merely an unexpected digression on Neandertal taxonomy.

With regard to the current debate over whether Neandertals are a Linnaean subspecies of Homo sapiens or a separate species altogether (Homo neanderthalensis), Marks advocates adopting the former scheme independent of any paleontological evidence. Neandertal taxonomic classification has really nothing to do with whether they could or could not interbreed with us, since this datum is never ascertainable for extinct fossils. Thus the conventional classification of fossils rests exclusively on morphological interpretation—exactly what he proposes be set aside in this deliberation. The rationale he offers is that shifting Neandertals up from subspecies to species status would "create a vacuum at the subspecies level, one that our folk ideologies about races and racial differences will all too readily fill," without regard for the adverse social consequences that might arise. This is a radical notion, for abandonment of systematic principles to some higher standard of value subordinates scientific discourse to ideology, or at least to admirable ideology. I doubt that many scientists are yet ready to go this far.

This cavil aside, Marks's book is a novel, intellectually provocative and wittily engaging treatment of a topic now a shibboleth of modern genetics. If it raises questions about scientists' social responsibility for which there are no easy answers, so much the better. They are important questions, too frequently evaded elsewhere.—Kenneth Korey, Anthropology, Dartmouth College