Catherine Nash’s Genetic Geographies offers a thorough and nuanced critique of recent developments in genetic genealogical research and the implications of this research for thinking race, ethnicity, identity, kinship, and nationality. The book is also an examination of how the science of genetic genealogy is translated into popular culture. This field involves heavily publicized research projects that bring genome science to a wider public: the Genographic Project is likely the best known given the familiarity of its sponsor, National Geographic, and the efforts to disseminate the findings and methods of this research on "human origins and mobility" through documentary films and primary and secondary school teaching resources. The book’s empirical material focuses primarily on scientific efforts to popularize and make more accessible the science of genetic ancestry, but is also conversant with debates over the utility of genetic genealogy within scientific communities. It analyses the guiding presumptions shared by other public projects in genetic genealogy, from commercial DNA-testing kits, popular guides, and television programs that bring the technology of genetic genealogy to a public audience. As Nash notes in this book, these many experiments in public science seek to demonstrate the utility of genetic analysis for understanding deep human history and in doing so, draw on a preponderance of geographical concepts and terms. What is at stake in the science of genetic genealogy is geography itself, or the "ideas of spatial boundedness, networks, propinquity, distance, extent, stretch, scale and origins" (22).

The book provides an extended overview of the contemporary efforts by gene scientists to distance their work from the field’s roots in racial science and to insist on the antiracist orientation of the study of human origins and genetic difference. While acknowledging that the emphasis on multiculturalism differentiates contemporary genetic genealogy projects from previous efforts to develop a science of human difference, Nash shows how these projects remain embedded in a political and social context in which gene science reaffirms categories of biological difference—albeit redefined around genetic categories such as "haplotype"—as the most salient for understanding fundamental forms of belonging and kinship. Nash examines in detail the different methodological starting points and assumptions made about "population" in the study of human genetic variation, including the work of both biomedical and anthropological geneticists. Here, anthropological geneticists’ interest in the genetic patterns and differences between people are used to postulate long lineages of human kinship (and ancestral people’s movements around the globe); biological geneticists’ concerns are with the different patterns within the human genome that may provide clues for understanding how genetic difference manifests in disease.

However, both groups of scientists, despite their methodological differences, define their objects of study by selecting representative samples of study populations. Nash focuses on these efforts to define and identify populations to understand how genetic researchers define population: as human groups already culturally defined by ethnicity, as patterns within a genetically "mixed" population of predefined categories taken from existing race-based distinctions between people, or as the effect of methods of "clustering" and generating models that produce defined categories even as the science of human variation suggests "clinical" patterns of variation rather than distinct, spatially-contained identities that map onto existing categories. All of these accounts of human variation suggest the cultural work that produces the science of variation cannot fully escape the reductive imaginary of racially distinct human groups.

In one chapter, Nash considers how the Genographic Project, led by geneticist and "explorer-in-residence" at the National Geographic Society, embodies one of the paradigmatic tensions in the broader project of anthropological genetics: the strenuous denial of race as a scientific fact despite continued reliance on the language of racial science. In Nash’s reading, the Genographic Project draws on a language of innocent curiosity about the existence of "human diversity" to re-code race as a universal and natural form of difference. The Project’s underlying assumption is that all human groups trace their lineage "back to Africa" and that the existing patterns of genetic diversity across the globe are the result of movements of people over thousands of years into communities that share patterns of genetic identity and difference.

The geographical implications of this are two-fold. As Nash writes, "Foregrounding shared haplotypes [genetic variants] as the basis of senses of connectedness suggests diminishing empathy with increasing biological difference"—in other words, shared genetic patterns are seen to as the basis for empathy, connection, and belonging. This story also reaffirms the racist rendering of Africa as origin point "left behind" by ancestral out-migration to the rest of the world.

Genetic science acknowledges the constructedness of racial categories, but at the same time re-affirms biological differences as originary and relies on fundamental distinctions between genetic identities that map onto racial categories. Nash deftly analyses the tensions in these claims: between liberal appeals to anti-racism (or as she notes, anti-racialism rather than anti-racism as a political project) and recognition of the multiculturalist societies in which gene science is received and carried out. In the UK, the search for genetic origins of the population understood as multicultural generates other tensions: the patterns of genetic ancestry across the UK affirm the articulation of a "mixed" but white "indigenous" identity. Multiculturalism in this sense applies to the diversity of the white population, rather than to any more expansive understanding of heterogeneity or the existence of any historical and contemporary migration other than that of "white" people.

The final chapter on sexual difference clarified some of the technical questions lingering from the previous chapters, specifically how the science of genetic genealogy differentiates maternal and paternal gene variants. Nash examines how the production of sexual difference is written into the field of genetic genealogy through the analysis of mitochondrial DNA (mtDNA), inherited by men and women from their mothers, and Y chromosome variants that are inherited only by men from their fathers. Comparing geographical differences in the distribution of combinations of mtDNA and Y chromosome variants is used as evidence for purportedly universal truths about the differences between men and women. Nash recounts how extremely troubling evolutionary imperatives continue to underpin presumptions about sexual behavior and sex difference: male dominance, violence, and sexual competition are all posited as naturally occurring dynamics of human evolution.

With great detail and attention to the stakes of her argument, Nash emphasizes how the language of "relatedness" supplements that of race, and in some cases operates to cover over the historical legacies of race-based projects on "genetic diversity" by offering a less controversial conceptual vocabulary for describing patterns and populations studied by genetic genealogists. Studies of the inheritance of sex-specific variants posit culturally specific imaginaries of masculine and feminine behavior as timeless and universal. Genetic genealogy does not completely break with the past practices of racial and evolutionary science, but subtly changes, reworks and transforms them. The book presents the seemingly contradictory assertions made by projects in genetic genealogy and details how the science of genetic ancestry justifies dubious cultural claims. However, we learn less of how the practice of genetic genealogy is remaking research participants’ or consumers’ senses of self, or how the reception of genetic ancestry research is, for example, shaping the teaching of geography or the practices of citizenship.  The book argues convincingly that scientific and media accounts of genetic genealogy draw contestable and often problematic conclusions, but doesn’t give us a detailed sense of how genetic genealogy research is being translated into these other domains. Will genetic genealogy research challenge or reinforce the resurgence of ethnocentric nationalism around the globe and specifically in the places examined in the book, the US and the UK? How would researchers track the new political identities emerging from the efforts of genetic genealogists to tell us "who we are?" Work in this area is starting to appear, for example in anthropological studies of the uses of genetic testing by indigenous groups. Nash’s book lays the groundwork for greater critical attention—by geographers and others—to these important issues. The book concludes with a critical discussion of the marketing practices of the commercial genetic genealogy sector, asking how the fascination with genetic ancestry will relate to the remaking of kin through assisted reproduction technologies and new configurations of family. An equally compelling question is how the pedagogies of genetic identity Nash carefully unpicks will inform the imaginaries of other "genetic geographies"—of population, community and citizen.

See Maria Fannin's most recent Society & Space contributions: Professional Citizenship and Medical Nationalism in France and Letting Geography Fall Where it May — Aerographies Address the Elemental