Spurious Subspecies

The Endangered Species Act (“ESA”), despite the name, protects both species and subspecific groups, like subspecies and distinct population segments (“DPS”).&nbsp; While there is agreement on the importance of protecting these subspecific units, there is substantial debate in both the legal and scientific communities about what each of these terms mean; their accepted definitions are often incongruent between the two fields.&nbsp; Recent changes in both science and law have brought issues of subspecific listings to fore.&nbsp; As our understanding of genetics has evolved, and our techniques to probe the evolutionary history of organisms have advanced, many modern biologists now view the concept of subspecies as irredeemably arbitrary.&nbsp; One recent study claimed that two-thirds of currently listed subspecies are illegitimate, making them ineligible for continued protection under the ESA.&nbsp; At the same time, recent Supreme Court precedent in cases like <i>Loper Bright</i> has dramatically shifted the balance of power in administrative law; judges rather than agencies are now expected to fill in the meaning of ambiguous statutes. <br> <br> In this paper, I examine both the history and future of agency efforts to list subspecies.&nbsp; This paper posits that the federal wildlife agencies and the courts have treated subspecies differently than they do other subspecific groups like DPSs.&nbsp; For subspecies, wildlife agencies have refused to define the term, making decisions on a case-by-case basis, and courts, though rarely asked, have traditionally deferred.&nbsp; On the other hand, the agencies have developed a regulatory definition for DPS and, as a result, the agencies have found themselves regularly defending these listings in front of far less deferential courts.&nbsp; This finding has taken on new salience in in an era where federal courts have become increasingly skeptical of agency interpretations and agency use of science in the wake of the death of <i>Chevron</i> deference.&nbsp; To aid courts now charged with defining these terms, I conclude by proposing a pluralistic definition of subspecies that captures both the evolved scientific understanding of the word and the broader policy aims of the ESA. <br> <br>