MICHAEL RUSSELLO results 30
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Climate change poses a significant threat to biodiversity, particularly in alpine ecosystems where species have already undergone elevational range shifts. Genomics can be used to estimate the adaptive potential of species, as well as the shift in adaptive genomic composition necessary for populations to adjust to climate change (e.g., genomic offset). Here, we investigated patterns of climate‐mediated adaptive genetic variati...
Recent ecotypic differentiation provides unique opportunities to investigate the genomic basis and architecture of local adaptation, while offering insights into how species form and persist. Sockeye salmon ( Oncorhynchus nerka ) exhibit migratory and resident (“kokanee”) ecotypes, which are further distinguished into shore‐spawning and stream‐spawning reproductive ecotypes. Here, we analysed 36 sockeye (stream‐spawning) and k...
Detailed information spanning the full annual cycle is lacking for most songbird populations. We examined breeding, migration, and non-breeding sites for the Yellow-breasted Chat ( Icteria virens, chat). We deployed archival GPS tags and light-level geolocators on breeding chats in British Columbia and light-level geolocators in California from 2013 to 2017 to determine migration routes and non-breeding sites. We examined whet...
Demographic history and patterns of molecular evolution from whole genome sequencing in the radiation of Galapagos giant tortoisesNARA Subscribed
Whole genome sequencing provides deep insights into the evolutionary history of a species, including patterns of diversity, signals of selection, and historical demography. When applied to closely related taxa with a wealth of background knowledge, population genomics provides a comparative context for interpreting population genetic summary statistics and comparing empirical results with the expectations of population genetic...
Genetically informed captive breeding of hybrids of an extinct species of Galapagos tortoiseNARA Subscribed
Hybridization poses a major challenge for species conservation because it threatens both genetic integrity and adaptive potential. Yet, hybridization can occasionally offer unprecedented opportunity for species recovery if the genome of an extinct taxon is present among living hybrids such that selective breeding could recapture it. We explored the design elements for establishing a captive‐breeding program for Galapagos torto...
Adaptive population divergence and directional gene flow across steep elevational gradients in a climate‐sensitive mammalNARA Subscribed
The ecological effects of climate change have been shown in most major taxonomic groups; however, the evolutionary consequences are less well‐documented. Adaptation to new climatic conditions offers a potential long‐term mechanism for species to maintain viability in rapidly changing environments, but mammalian examples remain scarce. The American pika ( Ochotona princeps ) has been impacted by recent climate‐associated extirp...
While genetic diversity is hypothesized to be an important factor explaining invasion success, there is no consensus yet on how variation in source populations or demographic processes affects invasiveness. We used mitochondrial DNA haplotypic and microsatellite genotypic data to investigate levels of genetic variation and reconstruct the history of replicate invasions on three continents in a globally invasive bird, the monk...
Genetic evidence for ecological divergence in kokanee salmonNARA Subscribed
The evolution of locally adapted phenotypes among populations that experience divergent selective pressures is a central mechanism for generating and maintaining biodiversity. Recently, the advent of high‐throughput DNA sequencing technology has provided tools for investigating the genetic basis of this process in natural populations of nonmodel organisms. Kokanee, the freshwater form of sockeye salmon ( Oncorhynchus nerka ),...
Lineage fusion in G alápagos giant tortoisesNARA Subscribed
Although many classic radiations on islands are thought to be the result of repeated lineage splitting, the role of past fusion is rarely known because during these events, purebreds are rapidly replaced by a swarm of admixed individuals. Here, we capture lineage fusion in action in a Galápagos giant tortoise species, Chelonoidis becki , from Wolf Volcano (Isabela Island). The long generation time of Galápagos tortoises and de...
In isolated oceanic islands, colonization patterns are often interpreted as resulting from dispersal rather than vicariant events. Such inferences may not be appropriate when island associations change over time and new islands do not form in a simple linear trend. Further complexity in the phylogeography of ocean islands arises when dealing with endangered taxa as extinctions, uncertainty on the number of evolutionary ‘units’...