Showing papers by "Museum of Texas Tech University published in 2004"
TL;DR: It is indicated that the samples from the Sierra Madre Occidental region of Durango and southeastern Sinaloa represent an undescribed species of Peromyscus, described herein as a new species.
Abstract: Historically, specimens representing the Peromyscus boylii species group from west-central Mexico have been referred to as Peromyscus boylii; however, a distinct but polymorphic karyotype (fundamental number 54–56) precludes an assignment of these specimens to currently recognized taxa. Phylogenetic analyses (parsimony, likelihood, and Bayesian) of DNA sequences indicated that samples from Durango, Mexico, formed a monophyletic clade that either was sister to P. levipes (parsimony) or to a clade containing P. beatae and P. levipes (likelihood and Bayesian). To refer these samples to P. boylii results in paraphyly and a significantly worse topology. Together, these results indicate that the samples from the Sierra Madre Occidental region of Durango and southeastern Sinaloa represent an undescribed species of Peromyscus. This taxon is described herein as a new species. The systematic status and phylogenetic relationships within the Peromyscus boylii species group from western Mexico have remained enigmatic since Osgood’s (1909) revision of the genus. Part of the dilemma stemmed from the potential occurrence of 3 subspecies (P. b. rowleyi, P. b. simulus, and P. b. spicilegus) in sympatry or near sympatry throughout parts of Durango, Nayarit, and Sinaloa. The long-standing dogma
36 citations
TL;DR: DNA sequences obtained from the mitochondrial cytochrome-b gene were used to evaluate phylogenetic relationships among 15 genera of putative neotomine–peromyscine rodents and revealed 4 primary clades that, in general, conform to the 4 tribes proposed by Carleton (1980).
Abstract: DNA sequences obtained from the mitochondrial cytochrome-b gene were used to evaluate phylogenetic relationships among 15 genera of putative neotomine–peromyscine rodents. Tree topologies obtained from maximum likelihood and Bayesian analyses revealed 4 primary clades that, in general, conform to the 4 tribes proposed by Carleton (1980). The Peromyscini (Megadontomys, Ochrotomys, Osgoodomys, Peromyscus, and Reithrodontomys) was sister to the Neotomini (Hodomys, Neotoma, Onychomys, and Xenomys). These 2 clades were then joined by the Baiomyini (Baiomys and Scotinomys) and Tylomyini (Nyctomys, Ototylomys, and Tylomys). The most apparent departure from previously proposed arrangements involved the placement of Onychomys in the Neotomini instead of the Peromyscini.
28 citations
TL;DR: DNA sequences from the mitochondrial cytochrome-b gene were used to examine the composition and phylogenetic relationships of the Peromyscus truei species group and indicated that the group should be divided into 2 species assemblages.
Abstract: DNA sequences from the mitochondrial cytochrome-b gene were used to examine the composition and phylogenetic relationships of the Peromyscus truei species group. Thirty-one individuals from the southwestern United States and Mexico were examined. Results indicated that 6 Peromyscus species (attwateri, difficilis, gratus, nasutus, pectoralis, and truei) compose the P. truei species group and that the group should be divided into 2 species assemblages. The relationship of the P. truei species group to the P. boylii and P. aztecus species groups was unresolved, indicating a close association of these 3 groups. In addition, levels of sequence divergence between sister taxa were higher than those reported for other sister species of Peromyscus.
24 citations
TL;DR: The level of genetic divergence between the clades of B. musculus is comparable to values seen between other sister species of sigmodontine rodents, and the Trans-Mexican Volcanic Belt, Sierre Madre del Sur, and Rio Balsas may separate populations of the species into northwestern and southern clades.
Abstract: The genus Baiomys contains 2 extant species, the northern B. taylori and the southern B. musculus. Mitochondrial DNA sequences from the cytochrome-b gene were used to assess genetic variation within and between the 2 species. Samples of B. taylori and B. musculus each formed 2 separate clades and differed by an average sequence divergence of 11.62%. Average sequence divergence between the 2 clades of B. taylori was minimal (2.82%), whereas the value between the 2 clades of B. musculus was greater (6.46%). The level of genetic divergence between the clades of B. musculus is comparable to values seen between other sister species of sigmodontine rodents. The Trans-Mexican Volcanic Belt, Sierre Madre del Sur, and Rio Balsas may separate populations of B. musculus into northwestern and southern clades.
21 citations
TL;DR: It appears that Dmp1 is phylogenetically informative at the tribal level in North American sigmodontine rodents.
Abstract: Despite previous work on the North American sigmodontine rodents, phylogenetic relationships within the neotomine–peromyscine complex remain conjectural. The debate focuses not only on the number of tribes within the group, but also on the relationships of genera within each tribe. Phylogenetic relationships of 19 species representing 13 genera of neotomine–peromyscine rodents were examined by using approximately 1,200 base pairs (bp) of exon 6 of the nuclear, protein-coding dentin matrix protein 1 gene (Dmp1). The topology obtained from the maximum likelihood analysis indicated that 4 tribes should be recognized: the Neotomini, Peromyscini, Baiomyini, and Tylomyini, with the Tylomyini sister to a rapidly radiating clade of neotomine–peromyscine–baiomyine rodents. In addition, it appears that Dmp1 is phylogenetically informative at the tribal level in North American sigmodontine rodents.
15 citations