The Epigenome and Nature/Nurture Reunification: A Challenge for Anthropology

Abstract

Recognition among molecular biologists of variables external to the body that can bring about hereditable changes in gene expression or cellular phenotypes has reignited nature/nurture discussion. These epigenetic findings may well set off a new round of somatic reductionism because research is confined largely to the molecular level. A brief review of the late nineteenth-century formulation of the nature/nurture concept is followed by a discussion of the positions taken by Boas and Kroeber on this matter. I then illustrate how current research into Alzheimer's disease uses a reductionistic approach, despite epigenetic findings in this field that make the shortcomings of reductionism clear. In order to transcend the somatic reductionism associated with epigenetics, drawing on concepts of local biologies and embedded bodies, anthropologists can carry out research in which epigenetic findings are contextualized in the specific historical, socio/political, and environmental realities of lived experience.

Keywords:

• embedded bodies
• epigenetics
• epigenome
• local biologies
• the superorganic

Notes

The genome is inherited at conception. Aside from a few somatic mutations that may take place during cell division, it remains unchanged in most cells of the body throughout the life cycle. In contrast, the epigenome, the product in part of the genome interacting with the environment, provides the molecular basis for cellular differentiation and development over the life course. The epigenome functions to constrain patterns of gene expression. It is increasingly evident that in humans certain of these changes can be passed on from mothers to offspring; see, for example, Kuzawa and Sweet (2009), and animal work has demonstrated paternal transmission of epigenetic changes to offspring.

2011 Gairdner Mini Epigenetics Symposium, Montréal, October 31.

After every cycle of DNA replication, several modifications occur in the DNA. DNA methylation is one such modification that takes place in numerous biological processes.

But see, for example, Kuzawa and Sweet (2009).

The National Institutes of Health defines a biomarker as “a characteristic that is objectively measured and evaluated as an indicator of normal biologic processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention” (http://www.everythingbio.com/glos/definition.php?ID=3716).

Discussion throughout this section is limited to so-called late-onset Alzheimer's disease and does not include ‘dominantly inherited Alzheimer's disease,’ a single gene disorder.

For readers who are not familiar with Encounters of Aging: Mythologies of Menopause in Japan and North America, my position is that whereas the end of menstruation is indeed a universal natural event for those women who live until age 50 or thereabouts, the idea of menopause is a medically founded concept that first emerged in nineteenth-century France.

I am indebted to Jörg Niewöhner for a stimulating exchange on the final third of this article.

Additional information

Notes on contributors

Margaret Lock

MARGARET LOCK is Marjorie Bronfman Professor Emerita at McGill University, Montréal. She is the author and editor of 15 books including the award-winning Twice Dead: Organ Transplants and the Reinvention of Death. Her forthcoming book is titled The Alzheimer Conundrum: Entanglements of Dementia and Aging.