TL;DR: The work attempts to explain the previously discovered phenomenon of excessive taxonomic status of the species and subspecies of Cuban hutias relative to their protein genetic divergence and suggests that the genetic divergence pattern of hutias in post-Pleistoce ne was predominantly determined by selection on the background of a relatively rapid formation of multiple morphotypes.
Abstract: The work attempts to explain the previously discovered phenomenon of excessive taxonomic status of the species and subspecies of Cuban hutias relative to their protein genetic divergence. The reasons underlying the fragmentary distribution of the species belonging to the family Capromyidae over the Antilles and Bahamas is also considered. Samples of four geographically distant hutia (genera Capromys and Mysateles) populations inhabiting different biotypes were assessed according to 32 allozyme loci. It has been demonstrated that the interpopulation and subspecies differentiation in the gene frequencies in these genera is very low. As for the pattern of polymorphism (Shannon’s measure), the populations and subspecies within these genera are well differentiated and adequate to their morphological differentiation. This suggests that the genetic divergence pattern of hutias in post-Pleistoce ne was predominantly determined by selection on the background of a relatively rapid formation of multiple morphotypes. It is assumed that the evolution within the family Capromyidae in the earlier and the later periods was associated with the geomorphological and climatic events in the history of the Earth. This standpoint provides for explaining the phenomena of both the excessive taxonomic status of the Cuban Capromyinae and the fragmentary distribution of these species over the Antilles and Bahamas, amazing at a first glance.
TL;DR: Evidence is found that Capromys pilorides contains a major species-level subdivision from western to eastern Cuba, spanning a greater geographic region than previously hypothesized, and detailed surveys are needed to assess the conservation status of these evolutionarily distinct Cuban taxa.
Abstract: The insular radiation of hutias is remarkable among mammals for its high rate of extinction during the Holocene (∼58% of species), yet fragments of intact habitat throughout the West Indies retain a critical portion of endemic diversity needing assessment. Cuba contains 8 of the 11 recognized living species of hutias, with surviving forms also on Hispaniola, Jamaica, and the Bahamas. Herein, we performed molecular phylogenetic analyses across populations of Cuban hutias in the genera Capromys, Mesocapromys, and Mysateles to address major gaps in our understanding of their species limits, phylogenetic structure, and geographic distributions. Comparing sequences of mitochondrial genes (cyt-b, COI, 12S rRNA) from 41 individuals and 21 sites across the archipelago, we found evidence that Capromys pilorides contains a major species-level subdivision from western to eastern Cuba, spanning a greater geographic region than previously hypothesized. Populations of Capromys in each clade last shared a common ancestor ∼1.1 million years ago (Ma; 5.2% cyt-b divergence). The western clade is further subdivided between mainland hutias (C. p. pilorides) and those on Isla de la Juventud plus Cayo Cantiles (C. p. relictus has priority). The eastern clade contains all Capromys east of Sierra del Escambray in central Cuba, including mainland and insular forms. However, without paired analyses of morphology and genetics or data from type localities, we cannot assign a name to the eastern Capromys sp. nov. at this time. Divergencetime analyses across 9 named species of hutias (plus 1 extinct), including nuclear genes (GHR, vWF, RAG1), dates the Capromyidae split from their South American relatives (Echimyidae) at 15.5 Ma. The crown radiation of hutias was 8.8 Ma, with successive divergences at 5.4 Ma (Geocapromys), 3.1 Ma (Capromys), and 2.2 Ma (Mysateles–Mesocapromys). Detailed surveys are needed to assess the conservation status of these evolutionarily distinct Cuban taxa.