“Nonlinear systems may exhibit qualitative transformations of behavior (bifurcations). The idea is simple: a single system may exhibit many different forms of behavior—all the result of the same basic dynamic. One equation, many faces. A corollary to this idea is that a system may have … multiple competing forms of behavior, each perhaps a hairsbreadth away, each representing stable mutual-effect organization.”99 Transposed to the realm of sexuality, this idea offers the potential for intriguing insights: heterosexuality, homosexuality, and all variants in between can be seen as alternative manifestations of a single sexual “dynamic,” as it were, which is itself part of a much larger nonlinear system. The “flux” of this system is played out in endless and infinitely varying expressions within individual lives, through various communities, between different species, across sequences of time, and so on and so forth.
Though chaos theory has been applied to various social phenomena, it has yet to be used in the analysis of patterns of sexual behavior. It remains to be seen whether something as relatively elusive as sexual and gender expression could even be quantified to the extent required by the rigorous mathematical models of chaos science. Nevertheless, the broader insights offered by chaos theory are readily apparent: seemingly incoherent or counterintuitive phenomena—whether in the realm of inorganic chemistry or “sexual chemistry”—are components of an overall pattern, regardless of whatever meaning (or lack thereof) they may have individually. In essence, deviation from the norm is part of the norm.
Biodiversity = Sexual Diversity
Gaia theory … has a profound significance for biology. It affects even Darwin’s great vision, for it may no longer be sufficient to say that organisms that leave the most progeny will succeed.
—JAMES E. LOVELOCK, “The Earth as a Living Organism”100
Nearly two decades ago, British scientist James Lovelock published his book Gaia: A New Look at Life on Earth, ushering in a new era in biological thought. What has come to be known as the Gaia hypothesis or Gaia theory has had an immeasurable impact on the way science looks at natural systems in general, and evolution in particular. Gaia theory says that the sum of all living and nonliving matter forms a single self- regulating entity, analogous to a giant living organism. Converging with the results of post-Darwinian evolutionary theory, the Gaia hypothesis has prompted a rethinking of some of the most basic principles of evolution. Cooperation, in addition to competition, is seen as an important force of evolutionary change, while the search for adaptive explanations at the level of the individual has been shifted upward to also include whole species as well as the functioning of the entire biosphere. Although not without controversy, Gaia theory has spawned a number of innovative ideas, many of which are beginning to be empirically and experimentally verified, and has led to important cross-disciplinary collaborations between scientists.101
Once again, these new strands of thought have powerful implications for the way animal homosexuality and, more broadly, systems of sexuality and gender are construed. As Lovelock (quoted above) has observed, reproduction is not necessarily a required component of “survival”—in some instances, it may be beneficial for a species or an ecosystem as a whole if some of its members do not procreate. Of course, it is overly simplistic to equate homosexuality with nonreproduction (since, as we saw in previous chapters, many animals that engage in same-sex activity also procreate). There is also little evidence to support the idea that homosexuality operates as a kind of large-scale “population-regulating” mechanism (perhaps the most obvious “function” that would be ascribed to homosexuality in a Gaian interpretation). Nevertheless, one of the fundamental insights of Gaia theory—the value it accords to “paradoxical” phenomena—is directly applicable to homosexuality and transgender. Indeed, the “mosaic” or mixture of male and female characteristics found in intersexual animals such as gynandromorphs is used by some Gaian theorists as a model of multiplicity within oneness, the transformation of disjuncture into wholeness—in other words, the very image of the earth itself.102
Like chaos theory, the Gaia hypothesis recognizes that phenomena that appear inexplicable at the level of an individual organism or population may be part of a larger, complex tapestry: a web of seemingly incongruous forces that interact to produce the flow of life, often in ways that are difficult to fathom. Nowhere is this idea better formulated than in the concept of biodiversity. Stated simply, this is the principle that the vitality of a biological system is a direct consequence of the diversity it contains: “as diversity increases, so does stability and resilience.”103 Traditionally, such diversity is thought of strictly in terms of number and types of species—that is, the physical composition of the system, usually expressed in terms of its overall genetic variety. Long-term studies of individual ecosystems have shown, for example, that the health and stability of a natural system is directly linked to the number of different species it contains.104
However, variability in number of species is not the only way that biological diversity can be expressed. At all levels of the natural world, social and sexual diversity exists—in every type of animal, and between different species, populations, and individuals. As an example, consider just one group of birds, the sandpipers and their relatives.105 An enormous variety of heterosexual and homosexual mating and social systems are found among the more than 200 species in this group. We find monogamous pairings between birds of the same or opposite sex (Black-winged Stilts, Greenshanks); polygamous associations such as one male mating with more than one female (northern lapwings, curlew sandpipers) or one female mating with more than one male (jacanas), or bisexual trios in which two birds of the same sex bond with each other and with a third individual of the opposite sex (Oystercatchers); and “promiscuous” systems in which birds court and mate with multiple partners of the same or opposite sex without establishing pair-bonds, often involving communal courtship display grounds or leks (Ruffs, Buff-breasted Sandpipers). Even within a particular mating system such as heterosexual “monogamy,” there are many different variations: some species form lifelong pair-bonds (e.g., Black Stilts); others are serially monogamous, forming sequential pairbonds or mating associations with different partners (kentish plovers, sanderlings); others are primarily monogamous but form occasional polygamous trios (Golden Plovers). Some species have largely “faithful” pair-bonds, with birds rarely if ever copulating with individuals other than their mate (Golden Plovers), while in others nonmonogamous matings with birds outside of the pair-bond are routine (Oystercatchers). And even within a given species, there are variations between different geographic areas: lesbian pairs occur in only certain populations of Black-winged and Black Stilts, for example, while snowy plovers exhibit extensive geographic variation in their heterosexual mating patterns, ranging from monogamy to serial polygamy (and numerous versions of each). Within a given population, there is also diversity between individual birds. In Oystercatchers, for example, only some birds participate in homosexual associations, nonmonogamous heterosexual copulations, or serial monogamy, while extensive numbers of nonreproducing birds that do not engage in either heterosexual or homosexual activities are also found in most species. And finally, each individual bird may participate in a variety of sexual and mating behaviors during its lifetime. Among male Ruffs, for example, some birds are exclusively heterosexual for their entire lives, some alternate between periods of heterosexual and homosexual activity or engage in both simultaneously, other individuals participate primarily in same-sex activities for most of their lives, while still others are largely asexual. Similar examples could be furnished from virtually any other animal group, especially now that detailed longitudinal studies are beginning to reveal individual (and idiosyncratic) life-history variations in nearly all organisms.
Scientists are beginning to find evidence that this diversity in social and mating systems contributes directly to the “success” of a species. For instance, among great bustards (a large, storklike bird found in southern Europe and North Africa), flexibility in heterosexual mating systems gives the birds a greater adaptability, enabling them to cope with difficult or variable ecological conditions.106 And in some species, homosexuality itself appears to be associated with environmental or social changes, in ways that are suggestive but (so far) poorly understood. Male pairing in Golden Plovers, for example, is claimed to be more prevalent in years when severe winter snowstorms have “disrupted” heterosexual pairing, while female coparenting among Grizzlies appears to be characteristic of animals living in conditions of environmental or social flux. In Ostriches, homosexual courtships may be linked to unusually rainy seasons that alter the species’ overall sexual and social patterns. Likewise, same- sex pairs in Ring-billed and California Gulls are more common in newly founded colonies that are experiencing rapid expansion, while homosexual activities in Rhesus and Stumptail Macaques (and a number of other primates) are often associated with changes in the composition or dynamics of the social group.107
Although the correlations between these factors need to be more systematically investigated—a linear, one-way, cause-and-effect relationship is surely not involved—they do suggest that sexual, social, and environmental variability may be closely allied. Specifically, the capacity for behavioral plasticity—including
