Exploring genetic and environmental constraints on life-history trait expression in wild North American red squirrels (Tamiasciurus hudsonicus)
Notice bibliographique
Résumé
Life-history trade-offs can occur when constraints on one trait or another limits phenotypic expression. These constraints or limits can be evolutionarily important factors like inherited genetic influences, ecologically important aspects of the environment like resource abundance, and/or physiological factors like the capacity to dissipate endogenous body heat. My thesis took an integrated approach to exploring some of the evolutionary, ecological, and physiological facets that impact wild small mammals in Canada’s northern Boreal forest, and how these facets intersect to influence phenotypic expression. It is also one of a few studies to test the links between phenotypic expression and genetic effects using multivariate response models in a wild setting, as well as to quantify how heritable proportions of phenotypic expression can change across an environmental gradient of food availability. In chapter 3, I found that the heritable fraction of phenotypic variance changes as resource availability changes, increasing during mast years for all three life-history traits compared to other years. Also, that variation in red squirrel life-history trait expression is strongly influenced by the resource environment, and evolution of these three life-history traits for red squirrels of the northern boreal forest may not be constrained by underlying genetic architecture. In chapter 4, I found that red squirrels show consistent phenotypic expression of parturition date regardless of resource environment, but also that there are little genetic constraints on the expression of juvenile growth rate and litter size. On top of this, due to an integrated approach, I tested how the resource environment affects phenotypic expression, and how environmental pressures compound (e.g., the combined effects of changes in resource abundance and ambient temperature), with reproductive phenology, elucidating new avenues of selection pressures. Chapter 5 suggests that due to the lack of direct effect of food during mast years on juvenile growth that there is an inherent effect of mast crops that allows for or spurs the expression of a compensatory allocation strategy by adult female red squirrels to their offspring. While chapter 6 suggests that increasing ambient temperatures, brought about by climate change, in conjunction with delays in parturition date may constrain red squirrel reproduction, potentially constraining the sustainability of their population. As our environments continues to change, with shifting phenologies (both with respect to food production and reproduction) and increasing summer ambient temperatures accelerated at high latitudes, it is imperative that we understand how these changes could constrain reproduction for wildlife and affect their capacity to respond to anthropogenic changes.
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 | 0,001 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 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 ».