Glenn Adelson

Background

I taught "Conservation Biology and Biodiversity" at Harvard from 1990 through 1999 and am the co-author of a book, Biodiversity: Exploring Values and Priorities in Conservation(Blackwell Scientific) which grew out of that class. I am currently working on a multi-disciplinary anthology Environment: An Interdisciplinary Anthology for Yale University Press. I have also taught Expository Writing at Harvard (1989 through 1999) and Endangered Species Law at Boston College Law School (2000).

Research Interests

My research project in the Pierce lab is a family-level analysis of the Lycaenidae that includes a molecular phylogeny and a life-history database, which together can be used as tools for different ways of assessing diversity within that group.

My primary biological and philosophical interest is the concept of diversity, which I feel has not been subjected to the rigorous analysis it deserves based on the frequency of its appearance in the biological literature. Here is a recent version of some of my thoughts on the matter. Please contact me if you would like to engage in a discussion of these issues:

Diversity is a slippery concept for many reasons. The first is that diversity is a term with no essential philosophical, political, aesthetic, or scientific content. Educational institutions claim to want diversity in their student body, but it is a circumscribed notion of diversity. To cite an extreme example, at the same time that President Rudenstine issued his statement on the value of diversity at Harvard, the undergraduate admissions committee denied the application of an otherwise top-rank student who had been found guilty years earlier of killing her mother under duress, thus passing up a unique opportunity to add to the diversity, on one axis, of the student body. This example illustrates that diversity is a meaningful concept only as an outgrowth of a stated set of values: we want a diversity of those things that we consider to have positive value. English professors want the canon opened up to ethnic writers and women to whom it has long been closed, but generally don,t want it opened up to those who espouse extreme racist, imperialist, or nationalistic points of view. Biologists like to see a diversity of species, as long as none of them are exotic weeds that have moved into an ecosystem through human importation or facilitation. Diversity may be important because it leads to greater stability in ecosystems, to cross-fertilization of ideas in an academic setting, or to a richer and more meaningful representation in a democracy, but it only takes on those positive attributes once the values of its promoters have been articulated. There is diversity in a forest in the number of leaves per tree, but no biologist notices; there is diversity in the classroom between left- and right-handed students, but no college admissions committee cares; and there is a diversity ona library shelf in the color of the bindings of the books that no English professor analyzes.

Diversity as a subject for scientific study cannot, at its deepest level, be objective -- every aggregation contains a limitless diversity of possible ways in which it might be deemed diverse. It is only after an investigator subjectively deems a particular array of qualities to be desirable that the investigation of the extent of that diversity begins. Biologists claim that biological diversity is desirable, but notice that they provide a diversity of reasons that this is so: species diversity in an ecosystem maintains the stability of that ecosystem; genetic diversity drives the process of evolution; ecosystem diversity protects watersheds and increases speciation; and biological diversity in all forms provides humans with an array of benefits, most particularly food, medicine, and protection. This diversity of reasons to value diversity has been codified in the United States Endangered Species Act, which specifically enumerates the reasons for preserving species threatened with extinction: "these species . . . are of esthetic, educational, historical, recreational, and scientific value (16 USCA §1531(a)(3)). These examples show that the study of biological diversity as an academic discipline is different from science, as typically characterized, in two important ways: it is not a study of universals or generalities, and it is not a discipline in which the claim for objectivity can be taken by its practitioners to be stronger, as most scientists claim about their enterprise, than the claim for objectivity of, for example, the literary critic or the political analyst.

Diversity is difficult to characterize for another important reason as well. Consider this thought experiment: we want to gather a collection of two-dimensional objects such that at each step in the gathering process the collection possesses the greatest degree of diversity. We start with a green circle. Next we are given the choice, in our creation of a diverse collection, between adding either a green square or a red circle. Which choice adds more to the diversity of what is now a collection of two? There is not only no objectively correct answer, but our subjective values (other than as a mere, unjustifiable, preference for shape diversity over color diversity) do not even help us to arrive at an answer. As I will elaborate in the Section V of this proposal (not included here), the loss of cod abundance can be characterized and evaluated in a variety of ways, and none of these ways is more accurate or more objective than any other, nor is there any way to aggregate the results from the separate methods into a single variable, the maximization of which provides the best conservation result.

Granting that the goal of the study of biological diversity is in the discovery of differences, we need to analyze carefully whether the tools that we have borrowed from disciplines that value the discovery of similarities are appropriate to the task. To do so, it is important to recognize that we are examining unlike units; we therefore need to come up with a bundle of methods for evaluating and comparing unlike units. Natural entities are not comparable in the mathematically rigorous sense that meters and grams are. Some kinds of species are not commensurable with other kinds of species, most kinds of ecosystems are not commensurable with other kinds of ecosystems, and no species is commensurable with any kind of ecosystem. When we break down the complexities of conservation issues into their component parts, sometimes we will find entities that are comparable. But most of the time we will not, and the challenge is to formulate a methodology for communicating a rigorous description of diversity in the absence of commensurable units.

In order to make intelligible comparisons, investigators in the biological sciences generally and conservation biology specifically have commonly resorted to the practice of reducing the occurrence and attributes of biological entities and phenomena to quantitative measures. There is both comfort and wisdom in such a practice, and a precision and economy of communication is the result. However, our understanding of biological diversity is limited when we employ quantitative methods alone to measure biodiversity. It would often be better (i.e., richer, and in fact, more accurate) to employ verbal descriptions and narrative. We tend to thinkthese latter methods are too unscientific, so we shy away from them. However, there are some comparisons, especially comparisons of difference, for which the tools used in the discipline of history (in the sense of the study of the unique manner in which particular natural entities evolved) may be better suited where detailed descriptions and narratives and statements of questions that do not necessarily have precise answers get us much farther towards a complex truth than reliance on a mathematical equation. Some, if not most, complex comparisons can be fully understood only with verbal descriptions and narratives. Something is lost in precision and economy, but far more is gained in accuracy and completeness.