Beyond DNA: How Epigenetics is Transforming our Understanding of Evolution

Beyond DNA: How epigenetics is transforming our understanding of evolution

Benjamin Oldroyd

Published by Melbourne University Publishing in 2023

304pp / $14.60 / 978-0522878868

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When we hear DNA, most of us are transported back to high school science class where we learned about genetics and heredity. You may have even done an exercise hypothesizing the appearance of your future children based on dominant and recessive traits, or perhaps you rolled dice to simulate the likelihood of inheriting certain genes. While DNA undeniably plays a key role in the inheritance of traits, scientific advancements have expanded our understanding to include other influential factors.

Researchers are revisiting the classic nature versus nurture debate—gaining insights into how environmental factors can shape the expression of traits, sometimes even before fertilization. This fascinating area of study is called epigenetics. Essentially, epigenetics can be defined as changes that modify gene expression without altering gene sequence. This means that even if two individuals have the same version of a gene (i.e., same allele), it does not guarantee that the trait the gene controls will manifest in the same way in both individuals.

Understanding epigenetics is important for several reasons. First, it helps us grasp the complexities at play with human development and health—revealing how our environment can influence our genetic expression. With a clearer idea of how we have been created, we can make informed choices that may enhance our well-being and that of future generations. Epigenetic knowledge can lead to more personalized medical treatments and preventive strategies, as we become aware of how lifestyle and environmental factors can change our genes’ expression patterns. Additionally, exploring epigenetics encourages a deeper appreciation for the interplay between nature and nurture, fostering a more holistic view of how we are knit together.

A good example of how the environment influences gene expression through epigenetics is seen in a study conducted in the early 2000s. Scientists compared DNA methylation levels (a mark of epigenetics) in children of mothers who were pregnant with them during the Dutch Hunger Winter famine (1944-1945) and their siblings who were born after the famine. DNA methylation patterns differed between the two groups and those exposed to the famine as fetuses were more likely to develop heart disease, schizophrenia, and type 2 diabetes. Further studies are working to understand the link between methylation patterns and disease susceptibility.

For those new to the world of genetics and epigenetics, Benjamin Oldroyd’s book, Beyond DNA: How epigenetics is transforming our understanding of evolution, serves as an excellent introduction. When I first picked up the book, I was anticipating an in-depth exploration of the biochemistry of epigenetics and its mechanistic role in God’s creation. I expected to gain insights that would enhance my understanding for the Biochemistry: Molecular Genetics course that I have taught for over 18 years. However, the book does not delve into the level of detail typically found in a 300-level biochemistry course. Instead, it offers a concise and accessible overview of epigenetics, making it a great starting point for beginners.

The author uses a conversational style to his writing—which he admits he found much joy in creating. The style of writing is different than a scientific textbook or a research paper. In fact, part of the book is fictitiously conversational with August Weismann (an evolutionary theorist from the 1800’s). Oldroyd imagines what questions could come up in the mind of someone who has not had the extent of today’s scientific knowledge introduced to them, and yet is familiar with the idea of genetics. He then gives a responsive dialog to those questions. Glossaries and simple images are used throughout the book to draw the reader along. I imagine that this book may be a breath of fresh air for a reader who wants to begin to understand genetics and epigenetics with the approachability of a narrative script.

Oldroyd presents an overview that will enable non-scientists to learn about current topics that scientists are wrestling with. The book is learner-friendly, providing a variety of summaries relating to the genetics of plants, fish, insects, birds, and mammals. I particularly enjoyed reading about transposable elements (TE) through this book. Oldroyd does a nice job of introducing his readers to what TEs are and then reviews how TEs are influenced by epigenetics and how TEs have contributed to genetic diversity—underscoring his argument that epigenetics has played a significant evolutionary role.

Oldroyd, is currently a Professor Emeritus at the University of Sydney. Having taught genetics and animal behavior for years, his book is a great accumulation of fun stories and insightful documentation of scientific knowledge that I imagine his fruitful career has bestowed upon him. He weaves together examples of worker and queen bees, the rapid adaptation of invasive species, the impact of environmental stressors and pathogens and speculates how epigenetics may have enabled successful adaptation in many of these cases before more permanent genetic alterations could be solidified.

Through his scientific summaries and speculative commentary, Oldroyd presents a compelling challenge: to continue to examine new scientific evidence and revise current theories, in line with the principles of the scientific method. In Beyond DNA, he argues for expanding the Modern Synthesis of Evolution to formally incorporate epigenetics as a key player in evolutionary biology. For scientists, this challenge may not come as a surprise, however, for readers not coming from a scientific background, this will be an intriguing and perhaps challenging read. This book serves as a valuable introduction to genetics and epigenetics, encouraging readers to think critically about how these concepts relate to their understanding of Creation, inviting them to reflect on how God has been, and continues to be, at work in the world and how we might leverage this knowledge to participate in God’s redeeming work.