The Symbiotic Nature of Animal Research

THE SYMBIOTIC NATURE OF ANIMAL RESEARCH HENRY E. HEEENER * In recent years the ethical basis for the use of animals by humans has been questioned, and political pressure has been brought to reduce, if not eliminate, our interaction with other animals [I]. While this situation has directly affected all who use animals commercially, few have been more affected than scientists who use animals in their research. As a result, researchers have found it necessary to defend their use of animals. The usual justification given for animal research is that the benefits of the research to humans outweighs the costs to the animals [2, 3] . However, this argument raises the question of how many animals we are justified in sacrificing in order to benefit ourselves. This question arises because the relationship between humans and animals is viewed as one-sided, with humans benefitting at the expense of animals. Indeed, so pervasive is this view that current U.S. government policy directs that the number of animals used in research be minimized and that alternatives to animal research be sought—with the implied goal of eventually ending animal research [4,5]. But is the use of animals in research (or, for that matter, for food and clothing) an exploitative relationship in which all of the benefits accrue to humans? In answering this question, it is important to realize that all living organisms have close relationships with others and that these relationships have been the subject of scientific study. Ironically, the knowledge gained from such studies has not been applied to the debate concerning the use of animals in science. The purpose of this paper is to examine our use of animals in terms of what is known about the relationships between living organisms, particularly symbiotic relationships. In doing so, it is necessary to consider the general issue of domestication, of which animal research is a part, and to examine the use of the reproductive strategy known as kin selection. As will be seen, such an analysis leads to conclusions that have relevance to our use of animals. *Department of Psychology, University of Toledo, Toledo, OH 43606.© 1999 by The University of Chicago. All rights reserved. 0031-5982/1999/4301-1 126$01.00 128 Henry F. Heffner ¦ The Symbiotic Nature ofAnimal Research Symbiosis The term symbiosis was first used in 1879 by Anton de Bary, a German mycologist at the University of Strasbourg, to refer to the living together or close association of two different species [6] . Although it sometimes has been used to refer to interactions in which both species (the symbionts) benefit, it is more commonly used in a broad sense to refer to all types of interactions. One form of symbiosis is parasitism, in which one symbiont obtains food and/or shelter at the expense of another, but without causing immediate death; indeed, it is the most common lifestyle found in nature [7] . Examples include the various bacterial, viral, and other diseases that infect all organisms including humans. A second form is commensalism, in which one species obtains food and/or shelter from another at little cost (or benefit) to the host. The house mice and rats that consume small amounts of our food and the mites that live in our beds are not considered to be noticeably detrimental to our survival, although they occasionally may be so [8, 9] . However, it is mutualism, in which both parties benefit, that is of most relevance here. A prime example is our own bodies, for humans, like other mammals, are properly considered as complex organisms consisting of animal cells and bacteria; the bacteria that inhabit our gut not only outnumber the cells of our body, but constitute a complex ecosystem whose metabolic activity is on par with that of the liver and without which we could not survive [10]. The measure of benefit derived from a mutualistic relationship is the amount that the relationship has contributed to the reproductive success of both species and, conversely, has reduced the probability that either might become extinct. Species that are considered relatively resistant to extinction have the following characteristics: (1) they are quite numerous, with the result that a sudden reduction in their numbers...