Are subspecies (ofEira barbara) real?

Abstract

The subspecies concept is one of the most controversial in Linnean taxonomy. In the past, subspecies were described without a clear conceptual framework, triggering confusion and motivating criticism of the very concept of a subspecies. At present, subspecies are conceived as aggregates of populations that are geographically isolated, are composed of interfertile individuals, and are morphologically diagnosable. The tayra, Eira barbara, was described in 1758 and has had a stable taxonomic history at the species level. However, below the species level, 16 subspecies have been named, with from two to seven subspecies recognized as valid by different authors. None of the subspecies were, however, described within a clear conceptual framework. Using the modern concept of a subspecies, I analyzed subspecies of E. barbara recognized by recent authors. I gathered morphometric data from 155 specimens in mammal collections, georeferenced each specimen, and recorded membership to subspecies assigned by different references and by its location. I gathered climate and geographic data for each location. I analyzed data using Principal Components Analysis (PCA) and analysis of variance (ANOVA). Specimens exhibited sexual dimorphism in size but not in skull shape. I used regression analysis to test for associations between skull shape and size and climate data. Geographic analyses documented that subspecies are not allopatric, violating one of the main properties of the subspecies concept. ANOVA showed significant differences in skull morphology between some pairs of recognized subspecies but not others. However, none of the subspecies segregated in the PCA. Thus, the recognized subspecies could not be diagnosed from morphological data, violating another property of the subspecies concept. Size varied greatly between the sexes using different schemes for recognized subspecies. Climate variables explained between 4% and 6% of size variation for males and females. Skull shape proved not to be geographically variable.

Andean rain shadow effect drives phenotypic variation in a widely distributed Austral rodent

“…However, we note that morphotypes are to a large extent congruent with the pattern of genomic variation uncovered by Valdez and D'Elía (2021). It is now understood that subspecies are not necessarily monophyletic at all loci (e.g., the mitochondrial genome), but as sets of mostly allopatric populations that are diagnosable (O'brien & Mayr, 1991; Patten, 2015; Schiaffini, 2020); currently, the usage of this category is undergoing a renaissance in the mammalian literature (for recent examples involving rodents see Pacheco et al, 2020; Patton & Conroy, 2017). In this venue, Cadenillas and D'Elía (2021) recently showed that the common degu ( Octodon degus ) has two mostly allopatric morphotypes associated with environmental gradients, which were recognized as subspecies.…”

“…agnosable(O'brien & Mayr, 1991;Patten, 2015;Schiaffini, 2020); currently, the usage of this category is undergoing a renaissance in the mammalian literature (for recent examples involving rodents seePacheco et al, 2020;Patton & Conroy, 2017). In this venue,Cadenillas and D'Elía (2021) recently showed that the common degu (Octodon degus) has two mostly allopatric morphotypes associated with environmental gradients, which were recognized as subspecies.…”

Tayra

“…The skull is elongated, rostrum is short, zygomatic arch is prominent and is the widest part of the skull, and skull shape is not geographically variable (Schiaffini 2020;Fig. 57.2).…”

“…Based on skull morphometrics, Schiaffini (2020) concluded that none of the current subspecies of the tayra can be recognized as valid taxa because the criteria proposed within the literature (body size and pelage coloration [Cabrera 1958, Hall 1981, Presley 2000; mtDNA [Ruiz-García et al 2013]; geographical provenance [Schiaffini 2020]) contravenes several properties of the subspecies concept. Currently, there is no reason to believe that the known differences in genetics among designated subspecies have an effect on the management of tayras.…”

Incorporating intraspecific variation into species responses reveals both their resilience and vulnerability to future climate change

“…Here, we employed avian subspecies as intraspecific groups to model species‐level climate change effects (Pearman et al 2010, Oney et al 2013, Lecocq et al 2016, Meynard et al 2017, Zhang and Kubota 2021). Subspecies are geographically distinct populations (Remsen 2010, Winker 2010, Schiaffini 2020) that can be adapted to local environments (Hausdorf 2021). This makes them useful units for conservation research and management (Jacobson et al 2016, Liu et al 2018, Hart et al 2021).…”