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As an individual whose only previous introduction to genetics was a section in a botany class almost 50 years ago, I certainly found Human Genetics challenging, but also highly instructive and worth the effort. The motivation to learn was strong since both my daughter and son-in-law have doctorates in biomedical science. In fact, my daughter gave me the book in hopes that by reading it I might have some idea of what she and her husband are talking about when they speak of their professions.
My initial sense of dread was partially alleviated in the first few pages. New words or concepts are printed in bold type throughout the book and are defined in the text as well as in a glossary at the back of the book. The author also adeptly uses similes and analogies to simplify complex concepts in a manner to which the reader can relate. On the first page she likened the human genome to the Rosetta Stone, with DNA, RNA, and protein comprising the three “languages” of the genome. What was also helpful in the first chapter was the “mini-glossary” that negated the necessity of flipping to the back of the book or searching through the text to look up definitions that simply did not stick in my mind. These may seem like inconsequential stylistic factors, but to someone who was quite ignorant about the subject, those factors made the difference between deciding to continue studying the book and declaring the project hopeless and quitting.
Throughout the book, the author also made it easier for the reader by, for example, consistently previewing what would be discussed in the next few paragraphs; discussing the information presented in tables or figures rather than simply presenting the illustrations; presenting information in clear chronological order; and explaining the history of experiments related to specific developments in the field.
Despite the fact that the information was presented logically and clearly and was in ways designed to enhance simplicity and comprehension, the neophyte reader of genetics should not be deluded into thinking that reading this book is easy. The history of the evolution of Homo sapiens and the history of experimentation and of the development of genetic concepts themselves are, by their nature, extremely complex and detailed with the interweaving of many factors, events, and ideas.
In particular, the first three chapters were rather daunting. In those chapters, the basics for comprehending genetics are presented and I often found it necessary to reread portions and find definitions in the glossary rather than trying to find where in the text a term was first used and defined. I had to read the first three chapters in small doses, interspersed with other activities so that my mind would not become overwhelmed with specifics to the point of losing sight of the forest because there were so many trees. These chapters take the reader from the origin of our physical human essence to how genes work. In the first chapter, the reader is introduced to a fascinating history of our evolution, which ties in genetic history with archeological, geographical, and linguistic history, as well as the role played by the development of agriculture. The second chapter chronicles the evolution of the field of human genetics culminating in the sequencing of the human genome. Along the way are descriptions of many experiments and the development of ideas and concepts that left me in awe of the creativity, investigative logic, and deductive ability of scientists who advanced our knowledge. The third chapter focuses on how genes work and employs a single-gene disease (cystic fibrosis; MIM 219700) to examine the levels of genetics from molecules and cells to individuals, families, and finally populations.
Starting with the very beginning of the fourth chapter, which discussed genes and health, and extending through the final two chapters, which related to genetic testing and to genetic and genomic technologies, respectively, all of the previous hard work paid off. Undoubtedly due in great part to the groundwork laid in the first three chapters, I could understand at least the gist of what was being presented without looking up any definitions, although I chose to look up definitions occasionally for the sake of more thorough comprehension. Another factor that made these chapters more experientially similar to reading a novel than translating a book that had been written in a foreign language was the content of the chapters. Specific diseases such as cardiovascular disease, cancer, PKU (MIM 261600), sickle cell disease (MIM 603903), and Huntington disease (MIM 143100) were employed to trace not only the evolution of our understanding but also the development of genetic testing, gene therapy techniques, and DNA-based technologies. The information is certainly up to date with the latest references having been published within the last year or so.
In my opinion, Ricki Lewis has done a remarkable job with this book. The only stylistic suggestions I have are extremely minor: to consistently translate centimeters into inches and kilograms into pounds for U.S. readers, and to indicate a page number if a table or figure referenced is many pages away from the current page.
Near the very end of the text the author states that about one percent of the 32 billion bases of the human genome encodes proteins, and a few pages later indicates that there are approximately 34 million DNA bases that constitute the human exome. I am giving this information to illustrate the microscopic detail of the subject matter covered by this book, the mind-boggling degree of detail and complexity, and the amazing fact that thanks to the work of Ricki Lewis, I can understand this information! I think I will now be able to have some idea of what my daughter and son-in-law are discussing, but I'll keep the glossary handy just in case.