Popular understanding holds that genetic changes create cancer. James DeGregori uses evolutionary principles to propose a new way of thinking about cancer’s occurrence. Cancer is as much a disease of evolution as it is of mutation, one in which mutated cells outcompete healthy cells in the ecosystem of the body’s tissues. His theory ties cancer’s progression, or lack thereof, to evolved strategies to maximize reproductive success.

Through natural selection, humans evolved genetic programs to maintain bodily health for as long as necessary to increase the odds of passing on our genes—but not much longer. These mechanisms engender a tissue environment that favors normal stem cells over precancerous ones. Healthy tissues thwart cancer cells’ ability to outcompete their precancerous rivals. But as our tissues age or accumulate damage from exposures such as smoking, normal stem cells find themselves less optimized to their ecosystem. Cancer-causing mutations can now help cells adapt to these altered tissue environments, and thus outcompete normal cells. Just as changes in a species’ habitat favor the evolution of new species, changes in tissue environments favor the growth of cancerous cells.

DeGregori’s perspective goes far in explaining who gets cancer, when it appears, and why. While we cannot avoid mutations, it may be possible to sustain our tissues’ natural and effective system of defense, even in the face of aging or harmful exposures. For those interested in learning how cancers arise within the human body, the insights in Adaptive Oncogenesis offer a compelling perspective.

Like all cellular organisms, humans run on electricity. Slight imbalances of electric charge across cell membranes result in sensation, movement, awareness, and thinking—nearly everything we associate with being alive. Robert Campenot offers a comprehensive overview of animal electricity, examining its physiological mechanisms as well as the experimental discoveries that form the basis for our modern understanding of nervous systems across the animal kingdom.

Cells work much like batteries. Concentration gradients of sodium and potassium cause these ions to flow in and out of cells by way of protein channels, creating tiny voltages across the cell membrane. The cellular mechanisms that switch these ion currents on and off drive all the functions associated with animal nervous systems, from nerve impulses and heartbeats to the 600-volt shocks produced by electric eels.

Campenot’s examination of the nervous system is presented in the context of ideas as they evolved in the past, as well as today’s research and its future implications. The discussion ranges from the pre-Renaissance notion of animal spirits and Galvani’s eighteenth-century discovery of animal electricity, to modern insights into how electrical activity produces learning and how electrical signals in the cortex can be used to connect the brains of paralyzed individuals to limbs or prosthetic devices. Campenot provides the necessary scientific background to make the book highly accessible for general readers while conveying much about the process of scientific discovery.

In the spirit of Voltaire—and occasionally in the spirit of P. G. Wodehouse—P. B. and J. S. Medawar have crafted for the life sciences a source of reference that is meant for browsing, a book both authoritative and filled with delights. The authors’ breadth of knowledge is encyclopedic— arranged, appropriately enough, from A to Z—but more than that, they illuminate the ideas of biology with wit and intelligence and uncommon good sense. They bridge the chasm in our culture between the technically and the humanistically trained, breaking the code of jargon that limits access to scientific understanding. The Medawars’ special gift is to offer, at the same time, a pleasurable introduction for the layman and a source of new insight for the specialist.

In this book we can find a clear and meaningful definition of interferon, a useful explanation of the immune system, and thoughtful essays on sociobiology, eugenics, and aging. But we also find: “It is a popular fallacy that chewing gum regains its flavor if removed from the mouth and parked, say, under a chair.”

Whether in a serious discussion of cancer or a whimsical reflection on “chicken and egg” imagery in science, the Medawars’ blend of fact, literary allusion, historical anecdote, mythical and folk tradition, and even professional gossip is a rewarding exercise in biology as a humanistic endeavor.

The evolutionist Ernst Mayr considered August Weismann “one of the great biologists of all time.” Yet the man who formulated the germ plasm theory—that inheritance is transmitted solely through the nuclei of the egg and sperm cells—has not received an in-depth historical examination. August Weismann reintroduces readers to a towering figure in the life sciences. In this first full-length biography, Frederick Churchill situates Weismann in the swirling intellectual currents of his era and demonstrates how his work paved the way for the modern synthesis of genetics and evolution in the twentieth century.

In 1859 Darwin’s tantalizing new idea stirred up a great deal of activity and turmoil in the scientific world, to a large extent because the underlying biological mechanisms of evolution through natural selection had not yet been worked out. Weismann’s achievement was to unite natural history, embryology, and cell biology under the capacious dome of evolutionary theory. In his major work on the germ plasm (1892), which established the material basis of heredity in the “germ cells,” Weismann delivered a crushing blow to Lamarck’s concept of the inheritance of acquired traits.

In this deeply researched biography, Churchill explains the development of Weismann’s pioneering work based on cytology and embryology and opens up an expanded history of biology from 1859 to 1914. August Weismann is sure to become the definitive account of an extraordinary life and career.