Book Review: Ancestry Reimagined – Dismantling the Myth of Genetic Ethnicities

Ancestry Reimagined: Dismantling the Myth of Genetic Ethnicities
By Dr Kostas Kampourakis
Published by Oxford University Press
ISBN-10: ‎‎0241986699, ISBN-13: 978-0241986691
Buy this book from Amazon UK

If you google 'DNA test kit', the household names that come up – such as Ancestry or 23andMe – promise to reveal your 'heritage', 'ethnicity' or 'paternity'. Notice a common theme? These products all offer interpretations about your identity or genealogy based on your DNA – not raw data. But can we trust those conclusions, and how do they interplay with our assumptions about ethnicity?

In Ancestry Reimagined: Dismantling the Myth of Genetic Ethnicities, Dr Kostas Kampourakis explores these questions in response to the increased commercialisation of DNA testing that has accompanied improvements in DNA sequencing over the last few decades. Dr Kampourakis is an academic specialising in science education at the University of Geneva, Switzerland, and has published several books on genetics and evolution aimed at the wider public. It may be no surprise, given the title of the book, that he is not a fan of DNA heritage tests.

Typically, test takers send a biological sample that companies can extract their DNA from. This DNA is sequenced, and customers receive their results in the form of a percentage of their genome that was 'matched' to specific geographical regions or socially recognised ethnic groups. This creates the impression that there is a pool of DNA sequences that can act as unique identifiers that were found in the genomes of specific historic populations, and that DNA sequencing can show our direct inheritance of these markers from our ancestors.

The reality is more abstract, as Dr Kampourakis details. Tests only examine small parts of your genome that can often have different sequences between individuals. They then compare these sequences to a reference database of those obtained from people that live in defined regions or identify with certain ethnicities in the present day.

Statistics are then used to estimate which reference group these small sequences were the best match to. The groups themselves, Dr Kampourakis argues, are mainly based on arbitrary human ideas of ethnicity or borders and are often also prone to biases when they are being sampled.

Ultimately, as Dr Kampourakis shows, DNA heritage test results are really probabilistic: 'The tests cannot indicate that a person's DNA is 40 percent Italian and 60 percent Irish as if it is a jigsaw puzzle. What the tests indicate is that 40 percent of a person's DNA is more similar to the reference group of the company described as Italian than any other of the groups.' Even then, these groups are not really our possible ancestors – they are our contemporaries.

Because of this, Dr Kampourakis proposes a re-imagining of DNA heritage testing as measuring 'relatedness' rather than thinking of ourselves as belonging to discreet ethnic groups defined by genetics (genetic essentialism). Indeed, he shows that there is little evidence for genetic markers that are unique to particular ethnic groups and goes further to demonstrate that genetic inheritance does not follow patterns that fit neatly within countries or communities.

I thought it was important that while Dr Kampourakis believes that ethnicities are mainly social constructs, he also embraces that they are still very real and integral to someone's identity, treatment by society and health outcomes. I thought that his consideration of this, and the ways that DNA heritage tests can affect someone's life, was sensitive and considered.

Crucially, the main effective use for DNA testing that Dr Kampourakis identifies is for determining close relatives, and he considers how this can be a blessing and a curse. Many African Americans, for example, use the tests to gain a better idea about their relatively recent genealogical history that is missing because of the transatlantic slave trade. On the other hand, Dr Kampourakis also explores what can happen when an unexpected result conflicts with someone's sense of identity, in a positive or negative light.

Overall, while I found the book fascinating and completely agreed with Dr Kampourakis' rejection of genetic essentialism, what I thought was impressive was the way that his case was presented for a lay audience to properly understand using simple family trees and diagrams. Still, I would not say that it would be a light read for this audience – the book is inevitably very dense with case studies, so such readers will probably spend a lot of time referring to these explanations as Dr Kampourakis prompts in the text.

On the other hand, Dr Kampourakis is adept at explaining philosophical concepts around biology and identity clearly and engagingly. For readers with a background in biosciences or genetics, I would highly recommend Ancestry Reimagined as a first step into considering the context and wider interpretations around our work. The book raises important questions around how ethnicity is linked to genetics beyond the commercial tests and throughout medical research.

While rejecting biological essentialism may seem natural in our era, many of the ideas Dr Kampourakis explores also challenge conventional thinking about genetics that have entered mainstream modern thought. He rejects, for example, the notion that DNA can always be viewed as our 'essence', which can be applied somewhat dogmatically in society. I will certainly be warier of how I discuss genetics in future after reading this book, and, from the perspective of a researcher, it reminded me of one of the golden rules of science: to never conflate data with interpretation.

Buy Ancestry Reimagined: Dismantling the Myth of Genetic Ethnicities from Amazon UK.