Uses of the present

Working with the living, human biologists are in a fortunate position to put individuals and populations of the past in their appropriate quantitative places and to identify and comprehend environmental "stresses" of previous times. Although some writers have romanticized the human past as a disease-free and natural existence, the evidence is strongly contradictory. Our ancestors and even our hominoid ancestors were much parasitized, with impairment of growth and function. Few had regular access to safe potable water. Their gritty diets were bacteria laden and often full of toxins, and the adequacy of diets was rarely predictable. High indoor occupancy rates facilitated the communication of respiratory diseases as well as mites, lice, fleas, and jiggers. Unventilated cooking and heating hearths made for elevated concentrations of carbon monoxide and particulate products of combustion. Living with animals, for warmth and protection, our Old World ancestors came to share their pathogenic fauna and so added tuberculosis, measles, influenza, smallpox, and numerous "plagues" to the list of human scourges. © 1994 Wiley-Liss, Inc.