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 qu antitative places and to identify and comprehend environmental ''stres ses'' of previous times. Although some writers have romanticized the h uman past as a disease-free and natural existence, the evidence is str ongly contradictory. Our ancestors and even our hominoid ancestors wer e much parasitized, with impairment of growth and function. Few had re gular access to safe potable water. Their gritty diets were bacteria l aden and often full of toxins, and the adequacy of diets was rarely pr edictable. High indoor occupancy rates facilitated the communication o f respiratory diseases as well as mites, lice, fleas, and jiggers. Unv entilated cooking and heating hearths made for elevated concentrations of carbon monoxide and particulate products of combustion. Living wit h animals, for warmth and protection, our Old World ancestors came to share their pathogenic fauna and so added tuberculosis, measles, influ enza, smallpox, and numerous ''plagues'' to the list of human scourges . (C) 1994 Wiley-Liss, Inc.