BONES, GENES, SYSTEMATICS, POLITICS, SCI-COMM, AND FERAL EQUID MANAGEMENT IN THE UNITED STATES: WHEN WILL WE PUT THE HORSE BEFORE THE CART?

While feral equids in the United States are protected under the Wild and Free-Roaming Horses and Burros Act (WFRH&B), the treatment of free-roaming domestic horses (Equus caballus) remains a wedge issue in environmental politics, with most critiques aimed at adoption and culling programs designed to maintain “appropriate management levels”. A position adopted by animal rights lobbyists and some paleobiologists is that E. caballus is a native species reintroduced to the Americas by Portuguese and Spanish colonists, following extirpation in the late Pleistocene-early Holocene. A more recently developed viewpoint denies E. caballus ever disappeared from North America, insisting that First Nation breeds are directly descended from prehistoric populations. These positions have gained mainstream acceptance due in part to analyses of ancient mitochondrial DNA allegedly supporting the conspecificity of large Pleistocene American equids with modern E. caballus. Wild horse advocates claim these studies confirm E. caballus is a native species and in dire need of federal protection beyond the WFRH&B Act. Here I argue that the debate over whether E. caballus is a native or invasive species has sidelined the prompt that should proceed it, “What constitutes E. caballus?”, as the species has never received a consistent, satisfactory cladistic diagnosis with respect to its purported relatives. While current practices in feral horse management should be scrutinized in the name of animal welfare and indigenous sovereignty, such political activism frequently and unnecessarily weaponizes premature interpretations of mitochondrial DNA (which can be affected by incomplete lineage sorting during rapid chromosomal speciation) to hold equid phylogenetics hostage in an intellectual twilight zone, divorced from the usual taxonomic procedures of vertebrate paleontology. This situation reflects a broader taxonomic inertia in ungulate systematics, hampering drafting and execution of effective, ethical conservation policy. Consequently, science journalists targeting issues in free-roaming equid management should be more cautious and discerning when reporting knowns and unknowns concerning hypothesized relationships between prehistoric horses and modern feral populations.