Phylogeography and Population Structure of the Prairie Skink (Eumeces Septentrionalis)
Notice bibliographique
Résumé
The geographical and geneological limits of species are firmly rooted in historical and current processes. Phylogenetic studies focus on the historical aspect and examine character states to estimate ancestor-descendent relationships. The number of described species in the world has been estimated at 1.4 to 1.8 million and other estimates suggest that as many as 30 million species may exist (May, 1990; Wilson, 1992). Phylogenetic studies provide the information needed to delimit and classify these species based on their historical relationships. Studies on species population structure focus on the current and historical processes acting on a species. These studies use a variety of methods and estimate gene flow and allele frequencies across the species range. This thesis is composed of three chapters that examine the phylogeny and population structure of the prairie skink, Eumeces septentrionalis. Chapter 1 reviews some of the current methods available for examining population structure and justifies the methods used in this study. Chapter 2 examines the phylogenetic relationships within Eumeces septentrionalis using DMA sequence data from two portions of the mitochondrial genome. Specifically, populations from the northern subspecies, E. s. septentrionalis, are compared with the southern subspecies, E. s. obtusirostris. These data along with the phylogenetic species concept are then used to examine the placement of E. s. septentrionalis and E. s. obtusirostris as one or two distinct species. Chapter 3 focuses on the population structure of E. septentrionalis specifically with respect to the northern populations to examine the recolonization pattern following Pleistocene glaciation events. Two field seasons in the spring and summer of 2001 and 2002 were conducted for this study during which sixty-four tissue samples were collected from individuals in Canada, North Dakota, South Dakota, Minnesota, Wisconsin, and Kansas. ND4 (807 bp) and d-loop (~747 bp) regions of the mitochondrial genome (ND4 and d-loop) were sequenced from the collected samples, and these data were used in both phylogenetic and population structure analyses. Phylogenetic analyses demonstrated a substantial sequence divergence and reciprocal monophyly between the northern and southern subspecies of E. septentrionalis. Uncorrected pairwise distance values between the northern and southern subspecies ranged from 6.7 - 7.0%, and the monophyly of the northern and southern subspecies, E. s. septentrionalis and E. s. obtusirostris, were strongly supported by both maximum parsimony (bootstrap = 100) and maximum likelihood analyses. These results support the morphological differences found in previous studies and suggest that these two subspecies may be on separate evolutionary trajectories. The population structure of the prairie skink, E. septentrionalis, was examined using nested clade analyses, which revealed isolation by distance with restricted gene flow as the inferred geographical pattern for northern populations (E. s. septentrionalis). This pattern reflects the lack of overlapping haplotypes in distant populations and was found at both the haplotype and upper clade levels. These results indicate that E. septentrionalis was likely subject to one or more vicariant events, and subsequently several localities probably acted as refugia and source populations during times of glacial advance and retreat.
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction distillée sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Apprise à partir de 10 348 étiquettes directes de Codex et de 10 348 étiquettes directes de Gemma. Le mode candidate est l'union des têtes enseignantes seuillées; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont ni des étiquettes humaines ni des étiquettes directes de modèles de pointe.
Scores Codex et Gemma par catégorie
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,000 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,000 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,001 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,000 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule tête enseignante, pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».