Phenotypic plasticity enables a single genotype to produce multiple phenotypes in response environmental variation. Plasticity may play critical role the colonization of novel environments, but its adaptive evolution is controversial. Here we suggest that rapid parallel regulatory adaptation Anolis lizards urban heat islands due primarily selection for reduced and/or reversed heat-induced maladaptive thermal conditions. We identify evidence polygenic across genes skeletal muscle...

We examined the circulatory mechanisms underlying adaptive increases in thermogenic capacity deer mice (Peromyscus maniculatus) native to cold hypoxic environment at high altitudes. Deer from high- and low-altitude populations were born raised captivity adulthood, then acclimated normoxia or hypobaric hypoxia (simulating ∼4300 m). Thermogenic (maximal O2 consumption, VO2max, during exposure) was measured hypoxia, along with arterial saturation (SaO2) heart rate (fH). Hypoxia acclimation...

Evolutionary adaptation to extreme environments often requires coordinated changes in multiple intersecting physiological pathways, but how such multi-trait occurs remains unresolved. Transcription factors, which regulate the expression of many genes and can simultaneously alter phenotypes, may be common targets selection if benefits induced outweigh costs negative pleiotropic effects. We combined complimentary population genetic analyses experiments North American deer mice (Peromyscus...

Comparative approaches in physiological genomics offer an opportunity to understand the functional importance of genes involved niche exploitation. We used populations Alewife (Alosa pseudoharengus) explore transcriptional mechanisms that underlie adaptation fresh water. Ancestrally anadromous Alewives have recently formed multiple, independently derived, landlocked populations, which exhibit reduced tolerance saltwater and enhanced Using RNA-seq, we compared responses population two after...

How often phenotypic plasticity acts to promote or inhibit adaptive evolution is an ongoing debate among biologists. Recent work suggests that promotes evolutionary divergence, though several studies have also suggested maladaptive can potentiate adaptation. The role of plasticity, adaptive, maladaptive, in divergence remains controversial. We examined the between two species Peromyscus mice differ native elevations. used cardiac mass as a model phenotype, since ancestral hypoxia-induced...

For small mammals living at high altitude, aerobic heat generation (thermogenesis) is essential for survival during prolonged periods of cold, but severely impaired under conditions hypobaric hypoxia. Recent studies in deer mice (Peromyscus maniculatus) reveal adaptive enhancement thermogenesis high- compared to low-altitude populations hypoxic cold stress, an that attributable modifications the metabolism muscles used shivering. However, because rely heavily on nonshivering mechanisms...

Synopsis Ecological transitions across salinity boundaries have led to some of the most important diversification events in animal kingdom, especially among fishes. Adaptations accompanying such include changes morphology, diet, whole-organism performance, and osmoregulatory function, which may be particularly prominent since divergent regimes make opposing demands on systems that maintain ion water balance. Research last decade has focused genetic targets underlying adaptations, notably by...

Adaptation to freshwater may be expected reduce performance in seawater because these environments represent opposing selective regimes. We tested for such a trade-off populations of the Alewife (Alosa pseudoharengus). Alewives are ancestrally anadromous, and multiple have been independently restricted (landlocked). conducted salinity challenge experiments, whereby juvenile from one anadromous landlocked were exposed on acute acclimation timescales. In response trials, derived varied degree...

Abstract Phenotypic plasticity has long played a central role in eco‐evolutionary theory, but it was not until 20 years ago that proposed the term encompasses two distinct phenomena—developmental and phenotypic flexibility. While this terminology since been adopted by some, question of whether they are phenomena remains contentious both frequently lumped under umbrella ‘plasticity.’ Here, we treat dichotomy between developmental flexibility as hypothesis, put forth set predictions follow...

Abstract Gene regulatory divergence is thought to play an important role in adaptation, yet its extent and underlying mechanisms remain largely elusive for local adaptation with gene flow. Local widespread marine species despite generally high connectivity often associated tightly linked genomic architectures, such as chromosomal inversions. To investigate evolution under flow the of inversions a steep thermal gradient, we generated RNA-seq data from Atlantic silversides (Menidia menidia)...

Abstract Aerobic performance is tied to fitness as it influences an animal’s ability find food, escape predators, or survive extreme conditions. At high altitude, where low O2 availability and persistent cold prevail, maximum metabolic heat production (thermogenesis) aerobic trait that closely linked survival. Understanding how thermogenesis evolves enhance survival at altitude will yield insight into the links between physiology, performance, fitness. Recent work in deer mice (Peromyscus...

Abstract Background Complex organismal traits are often the result of multiple interacting genes and sub-organismal phenotypes, but how these interactions shape evolutionary trajectories adaptive is poorly understood. We examined functional between cardiorespiratory contribute to increases in capacity for aerobic thermogenesis (maximal O 2 consumption, V̇ max, during acute cold exposure) high-altitude deer mice ( Peromyscus maniculatus ). crossed highland lowland produce F inter-population...

Understanding the links between genetic variation and fitness in natural populations is a central goal of evolutionary genetics. This monumental task spans fields classical molecular genetics, population biochemistry, physiology, developmental biology, ecology. Advances to our toolkits are facilitating integrative approaches across these traditionally separate fields, providing more complete picture genotype-phenotype map non-model systems. Here, we summarize research presented at first...

Abstract The gene encoding HIF‐2α, Epas1 , has experienced a history of natural selection in many high‐altitude taxa, but the functional role mutations this is still poorly understood. We investigated influence variant North American deer mice ( Peromyscus maniculatus ) on control breathing and carotid body growth during chronic hypoxia. created hybrids between high‐ low‐altitude populations to disrupt linkages genetic loci so that physiological effects alleles H L respectively) could be...

Whole-organism performance tasks are accomplished by the integration of morphological traits and physiological functions. Understanding how evolutionary change in morphology physiology influences whole-organism will yield insight into factors that shape its own evolution. We demonstrate nonmigratory populations alewife (Alosa pseudoharengus) have evolved reduced swimming parallel, compared with their migratory ancestor. In contrast to theoretically empirically based predictions, poor among...

Physiological systems often have emergent properties but the effects of genetic variation on physiology are unknown, which presents a major challenge to understanding mechanisms phenotypic evolution. We investigated whether variants in haemoglobin (Hb) that contribute high-altitude adaptation deer mice (Peromyscus maniculatus) associated with evolved changes control breathing. created F2 inter-population hybrids highland and lowland test for associations α- β-globin mixed background. Hb...

ABSTRACT Predicting the success of a species' colonization into novel environment is routinely considered to be predicated on niche‐space similarity and vacancy, as well propagule pressure. The role genomic variation plays in (and interaction with environment) may suggested, but has not rigorously been documented. To test an hypothesis that previously observed ecotype‐specific polymorphisms between anadromous landlocked alewife ( Alosa pseudoharengus ) populations are adaptive response...

Abstract Aerobic performance is tied to fitness as it influences an animal’s ability find food, escape predators, or survive extreme conditions. At high altitude, where low O 2 availability and persistent cold prevail, maximum metabolic heat production (thermogenesis) aerobic trait that intimately linked survival. Understanding how thermogenesis evolves enhance survival at altitude will yield insight into the links between physiology, performance, fitness. Recent work in deer mice (...

Abstract Transitions across ecological boundaries, such as those separating freshwater from the sea, are major drivers of phenotypic innovation and biodiversity. Despite their importance to evolutionary history, we know little about mechanisms by which transitions accomplished. To help shed light on these mechanisms, generated first high-quality, near-complete assembly annotation genome American shad (Alosa sapidissima), an ancestrally diadromous (migratory between salinities) fish in order...

Abstract Background Complex organismal traits are often the result of multiple interacting genes and sub-organismal phenotypes, but how these interactions shape evolutionary trajectories adaptive is poorly understood. We examined functional between cardiorespiratory contribute to increases in capacity for aerobic thermogenesis (maximal O 2 consumption, V◻O max, during acute cold exposure) high-altitude deer mice ( Peromyscus maniculatus ). crossed highland lowland produce F inter-population...

The transition from freshwater to seawater represents a physiological challenge for Atlantic salmon smolts preparing downstream migration. Stressors occurring during migration the ocean impair ability of maintain osmotic/ionic homeostasis in seawater. molecular mechanisms underlying this interaction are not fully understood, especially at organ level. We combined RNA-Seq with measures whole-animal examine gene expression dynamics gills associated impaired tolerance after an...