In this new book, Marlene Zuk critically evaluates current topics related to the paleolithic lifestyle. The author elaborates on the discrepancies of the popular belief that we are meant to live as our ancestors did, addressing issues of love and family, diet and exercise, health and disease, all in the context of human evolution. She is author of several publications, including Sex on Six Legs: Lessons on Life, Love and Language from the Insect World, and Riddled with Life: Friendly Worms, Ladybug Sex, and the Parasites That Make Us Who We Are. According to Zuk, “to assume that we evolved until we reached a particular point and now we are unlikely to change for the rest of history…is to miss out on some of the most exciting developments in evolutionary biology.” She posits that evolution is not a straight line, and claiming that we were at our peak performance in the past is clear ignorance of this fact.
One topic the author expounds upon in the book is the claim that we evolved to have multiple sexual partners. She begins the chapter by questioning our true sexual nature, asking if we indeed demonstrate similar sexual behaviors as our ancestors and how much of it might still be manifested today. Zuk begins the discussion by stating that human females rely on help in rearing their offspring, usually given by the father. As a result, it would seem that monogamy is natural in order to successfully raise a family. Others disagree, based on the proposition that fewer paleo men actually reproduced (less than half), and the higher reproductive rates of males in today’s society (80–90%) gives the false impression that monogamy is natural. Many of those who contend this point see monogamy “as a miserably failed experiment,” leading to dissolution of over half of all marriages.
Zuk also takes on the “paleo diet,” which has gained momentum recently with the claim that it can help prevent cardiovascular disease, obesity, cancer, type 2 diabetes, and a range of other ailments that plague our current society. The diet itself is based on the premise that if we eat as our ancestors did, that is, wholesome, natural foodstuffs from the same food groups that our hunter-gatherer ancestors would have relied on, we will live healthier and longer lives. In several chapters, Zuk analyzes what she calls the “gene–culture interaction.” Her examples of lactose intolerance and grain avoidance are at the heart of her argument that assumptions of the paleo diet are incorrect from an evolutionary standpoint. For instance, she claims that the argument that “we are simply not used to [grains] nor have we been given enough time to get used to them” is a fallacy, since the remains of Neanderthal teeth show wear and tear associated with eating “grass seeds, date palms, and a few other plants.” For Zuk, it boils down to the question of whether our genes or our modern lifestyle make us sick. She emphasizes how much both our genetic makeup and our lives have changed in the 10,000 years since agriculture was developed, making us significantly different from our paleo ancestors. Disease has always been with us, not simply since the birth of agriculture or urban living. As she states, “Life is an endless series of checks and balances with no guarantees to a happy ending.”
Although this book may seem dry at points, it does discuss a fascinating topic that is comprehensible to a reader not educated in evolutionary biology. It touches on topics such as monogamy, diet, and disease, which will be of interest to many different readers. The author does a commendable job explaining these topics but tends to belabor a few points and meander from her primary thesis on occasion. Each chapter, focusing on a different topic of our paleolithic past, is full of endless examples that support her thesis. For readers without a biology background or a strong interest in evolution, the book may be a bland and boring conversation, each chapter repetitive as she makes the same argument with different facts. To a reader with a scientific background, however, these facts are golden nuggets of information that strongly support her argument.