For most of the past few million years, our evolutionary ancestors' survival depended on being able to consume as much as possible when food was available and to store the excess energy for periods when it was scarce. In the developed world today, high-calorie foods are readily obtainable, yet the propensity to store fat is part of our species' heritage, leaving an increasing number of the world's people vulnerable to obesity. In an environment of abundant food, we are anatomically, physiologically, metabolically, and behaviorally programmed in a way that makes it difficult for us to avoid gaining weight.
Power and Schulkin’s engagingly argued book draws on popular examples and sound science to explain our expanding waistlines and to discuss the consequences of being overweight for different demographic groups. They review the various studies of human and animal fat use and storage, including those that examine fat deposition and metabolism in men and women; chronicle cultural differences in food procurement, preparation, and consumption; and consider the influence of sedentary occupations and lifestyles.
A compelling and comprehensive examination of the causes and consequences of the obesity epidemic, The Evolution of Obesity offers fascinating insights into the question, Why are we getting fatter?
Michael L. Power is a senior research associate at the American College of Obstetricians and Gynecologists and a research associate at the Smithsonian National Zoological Park. Jay Schulkin is director of the research department at the American College of Obstetricians and Gynecologists and a research professor in Georgetown University's Department of Neuroscience. Power and Schulkin are the coauthors of The Evolution of the Human Placenta, also published by Johns Hopkins.
After revealing the roots of lactation, the authors describe the substances that naturally occur in milk and discuss their biological functions. They reveal that mothers pass along numerous biochemical signals to their babies through milk. The authors explain how milk boosts an infant’s immune system, affects an infant’s metabolism and physiology, and helps inoculate and feed the baby’s gut microbiome.
Throughout the book, the authors weave in stories from studies of other species, explaining how comparative research sheds light on human lactation. The authors then turn their attention to the fascinating topic of cross-species milk consumption—something only practiced by certain humans who evolved an ability to retain lactase synthesis into adulthood. The first book to discuss milk from a comparative and evolutionary perspective, Power and Schulkin’s masterpiece reveals the rich biological story of the common thread that connects all mammals.
Starting with some of the earliest events that have influenced the path of placental evolution in mammals and progressing to the specifics of the human placenta, this book examines modern gestation within an evolutionary framework. Human beings are a successful species and our numbers have increased dramatically since our earliest days on Earth. However, human fetal development is fraught with poor outcomes for both the mother and fetus that appear to be, if not unique, far more common in humans than in other mammals. High rates of early pregnancy loss, nausea and vomiting during pregnancy, preeclampsia and related maternal hypertension, and preterm birth are rare or absent in other mammals yet not unusual in humans.
Power and Schulkin explain why this apparent contradiction exists and address such topics as how the placenta regulates and coordinates the metabolism, growth, and development of both mother and fetus, the placenta’s role in protecting a fetus from the mother’s immune system, and placental diseases. In the process, they reveal the vital importance of this organ—which is composed mostly of fetal cells—for us as individuals and as a species.-- Errol R. Norwitz, Tufts University School of Medicine and Tufts Medical Center