31° South: the physiology of adaptation to arid conditions in a passerine bird.
- Authors: Ribeiro, Ângela M , Puetz, Lara , Pattinson, Nicholas B , Dalén, Love , Deng, Yuan , Zhang, Guojie , da Fonseca, Rute R , Smit, Ben , Gilbert, M. Thomas P
- Date: 2019
- Subjects: To be catalogued
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/441508 , vital:73894 , https://doi.org/10.1111/mec.15176
- Description: Arid environments provide ideal ground for investigating the mechanisms of adaptive evolution. High temperatures and low water availability are relentless stressors for many endotherms, including birds; yet birds persist in deserts. While physiological adaptation probably involves metabolic phenotypes, the underlying mechanisms (plasticity, genetics) are largely uncharacterized. To explore this, we took an intraspecific approach that focused on a species that is resident over a mesic to arid gradient, the Karoo scrub‐robin (Cercotrichas coryphaeus). Specifically, we integrated environmental (climatic and primary productivity), physiological (metabolic rates: a measure of energy expenditure), genotypic (genetic variation underlying the machinery of energy production) and microbiome (involved in processing food from where energy is retrieved) data, to infer the mechanism of physiological adaptation. We that found the variation in energetic physiology phenotypes and gut microbiome composition are associated with environmental features as well as with variation in genes underlying energy metabolic pathways. Specifically, we identified a small list of candidate adaptive genes, some of them with known ties to relevant physiology phenotypes. Together our results suggest that selective pressures on energetic physiology mediated by genes related to energy homeostasis and possibly microbiota composition may facilitate adaptation to local conditions and provide an explanation to the high avian intraspecific divergence observed in harsh environments.
- Full Text:
- Date Issued: 2019
Extended and Continuous Decline in Effective Population Size Results in Low Genomic Diversity in the World’s Rarest Hyena Species, the Brown Hyena
- Authors: Westbury, Michael V , Hartmann, Stefanie , Barlow, Axel , Wiesel, Ingrid , Leo, Viyanna , Welch, Rebecca J , Parker, Daniel M , Sicks, Florian , Ludwig, Arne , Dalén, Love , Hofreiter, Michael
- Date: 2018
- Language: English
- Type: text , article
- Identifier: http://hdl.handle.net/10962/124482 , vital:35616 , https://doi.org/10.1093/molbev/msy037
- Description: Hyenas (family Hyaenidae), as the sister group to cats (family Felidae), represent a deeply diverging branch within the cat-like carnivores (Feliformia). With an estimated population size of < 10,000 individuals worldwide, the brown hyena (Parahyaena brunnea) represents the rarest of the four extant hyena species and has been listed as Near Threatened by the IUCN. Here, we report a high-coverage genome from a captive bred brown hyena and both mitochondrial and low coverage nuclear genomes of 14 wild-caught brown hyena individuals from across southern Africa.We find that brown hyena harbor extremely low genetic diversity on both the mitochondrial and nuclear level, most likely resulting from a continuous and ongoing decline in effective population size that started_1Ma and dramatically accelerated towards the end of the Pleistocene. Despite the strikingly low genetic diversity, we find no evidence of inbreeding within the captive bred individual and reveal phylogeographic structure, suggesting the existence of several potential subpopulations within the species.
- Full Text:
- Date Issued: 2018