Alfredo G. Nicieza

University of Oviedo | UNIOVI · Department of Organisms and Systems Biology

Critical thermal limits (CTmax and CTmin) decrease with elevation, with greater change in CTmin, and the risk to suffer heat and cold stress increasing at the gradient ends. A central prediction is that populations will adapt to the prevailing climatic conditions. Yet, reliable support for such expectation is scant because of the complexity of inte...

Body shape and metabolic rate can be important determinants of animal performance, yet often their effects on influential traits are evaluated in a non-integrated way. This creates an important gap because the integration between shape and metabolism may be crucial to evaluate metabolic scaling theories. Here, we measured standard metabolic rate in...

Serially connected robots are promising candidates for performing tasks in confined spaces such as search and rescue in large-scale disasters. Such robots are typically limbless, and we hypothesize that the addition of limbs could improve mobility. However, a challenge in designing and controlling such devices lies in the coordination of high-dimen...

Due to the speed of climate changes, rapid buffering mechanisms such as phenotypic plasticity – which may depend on breeding phenology – could be key to avoid extinction. The links between phenology and plasticity, however, remain understudied. Here we explored the matching between phenology and the thermal sensitivity of standard (SMR) and routine...

The ability to bear live offspring, viviparity, has evolved multiple times across the tree of life and is a remarkable adaptation with profound life-history and ecological implications. Within amphibians the ancestral reproductive mode is oviparity followed by a larval life stage, but viviparity has evolved independently in all three amphibian orde...

Reproductive isolation is instrumental to the formation of new species (speciation), but it remains largely enigmatic how many incompatibilities are required to prevent hybridization and where they lie across the genome. By studying patterns of admixture in amphibian hybrid zones, we found that reproductive isolation is initiated by numerous small-...

Critical thermal limits (CTmax and CTmin) are predicted to decrease with elevation, with greater change in CTmin, and the risk to suffer heat and cold stress increasing at the gradient ends. A central prediction is that populations will adapt to the prevailing climatic conditions. Yet, reliable support for such expectation is scant because of the c...

Explicitly accounting for phenotypic differentiation together with environmental heterogeneity is crucial to understand the evolutionary dynamics in hybrid zones. Species showing intra-specific variation in phenotypic traits that meet across environmentally heterogeneous regions constitute excellent natural settings to study the role of phenotypic...

Effective management of exploited populations is based on an understanding of population dynamics and evolutionary processes. In spatially structured populations, dispersal is a central process that ultimately can affect population growth and viability. It can be influenced by environmental conditions, individual phenotypes, and stochastic factors....

Many animals generate propulsive forces by coordinating legs, which contact and push against the surroundings, with bending of the body, which can only indirectly influence these forces. Such body–leg coordination is not commonly employed in quadrupedal robotic systems. To elucidate the role of back bending during quadrupedal locomotion, we study a...

The reduction in fecundity associated with the evolution of viviparity may have far‑reaching implications for the ecology, demography, and evolution of populations. the evolution of a polygamous behaviour (e.g. polyandry) may counteract some of the effects underlying a lower fecundity, such as the reduction in genetic diversity. comparing patterns...

Variation and population structure play key roles in the speciation process, but adaptive intraspecific genetic variation is commonly ignored when forecasting species niches. Amphibians serve as excellent models for testing how climate and local adaptations shape species distributions due to physiological and dispersal constraints and long generati...

1. The vulnerability of species to climate change is jointly influenced by geographic phenotypic variation, acclimation, and behavioral thermoregulation. The importance of interactions between these factors, however, remains poorly understood. 2. We demonstrate how advances in mechanistic niche modelling can be used to integrate and assess the inf...

Identifying the evolutionary processes that underlie morphological variation at the intraspecific level is cornerstone for understanding the drivers of phenotypic diversity at higher macro-evolutionary scales. The fire salamander, Salamandra salamandra, exhibits exceptional intraspecific variation in multiple phenotypic traits (i.e. body size, head...

Subdivided Pleistocene glacial refugia, best known as “refugia within refugia”, provided opportunities for diverging populations to evolve into incipient species and/or to hybridize and merge following range shifts tracking the climatic fluctuations, potentially promoting extensive cytonuclear discordances and “ghost” mtDNA lineages. Here we tested...

Insights into the causal mechanisms that limit species distributions are likely to improve our ability to anticipate species range shifts in response to climate change. For species with complex life‐histories, a mechanistic understanding of how climate affects different lifecycle stages may be crucial for making accurate forecasts. Here we use mech...

Complex life-histories may promote the evolution of different strategies to allow optimal matching to the environmental conditions that organisms can encounter in contrasting environments. For ectothermic animals, we need to disentangle the role of stage-specific thermal tolerances and developmental acclimation to predict the effects of climate cha...

The evolution of complex traits is often shaped by adaptive divergence. However, very little is known about the number, effect size, and location of the genomic regions influencing the variation of these traits in natural populations. Based on a dense linkage map of the common frog, Rana temporaria, we have localized, for the first time in amphibia...

The canonical model of sex-chromosome evolution predicts that, as recombination is suppressed along sex chromosomes, gametologs will progressively differentiate, eventually becoming heteromorphic. However, there are numerous examples of homomorphic sex chromosomes across the tree of life. This homomorphy has been suggested to result from frequent s...

Adaptation to warming climates could counteract the effects of global warming. Thus, understanding how species cope with contrasting climates may inform us about their potential for thermal adaptation and which processes may hamper that ability (e.g. evolutionary trade‐offs, phenology, or behavioural thermoregulation). In addition to temperature, t...

Many quadrupedal animals have lateral degrees of freedom in their backs that assist locomotion. This paper seeks to use a robotic model to demonstrate that back bending assists not only forward motion, but also lateral and turning motions. This paper uses geometric mechanics to prescribe gaits that coordinate both leg movements and back bending mot...

Dispersal is a central process in ecological and evolutionary dynamics because of its implications in spatially structured populations, that can affect population persistence either in the short or the long term. Movements away from the natal sites can be influenced by environmental conditions, individual phenotypes, and stochastic factors, but we...

This study probes the underlying locomotion principles of earliest organisms that could both swim and walk. We hypothesize that properly coordinated leg and body movements could have provided a substantial benefit toward locomotion on complex media, such as early crawling on sand. In this extended abstract, we summarize some of our recent advances...

Phenotypic plasticity can be viewed as the first level of defense of organism homeostasis against environmental stress and therefore represents the potential to deal with rapid environmental changes. Transitions between low complexity, artificial environments and complex, natural habitats can promote phenotypic plasticity. Here, we conducted an exp...

Individual animals introduced to supply existing populations may show a variety of physiological and phenotypic traits that may affect their performance in the wild, but a lack of monitoring after release usually precludes us from knowing the fate of different types of individuals and their impact on the recipient populations. Mark-recapture monito...

By combining 7077 SNPs and 61 microsatellites, we present the first linkage map for some of the early diverged lineages of the common frog, Rana temporaria, and the densest linkage map to date for this species. We found high homology with the published linkage maps of the Eastern and Western lineages but with differences in the order of some marker...

The existence of two or more distinctly coloured phenotypes among individuals of an interbreeding population is known as colour polymorphism. In amphibians, this phenomenon is pervasive among anurans, but rare or absent among salamanders and caecilians, respectively. Here, we examine whether various distinct phenotypes of Salamandra salamandra in N...

The climate variability hypothesis (CVH) states that a positive relationship may exist between the breadth of thermal tolerance range and the level of climatic variability experienced by taxa with increasing latitude, especially in terrestrial ectotherms. Under CVH, we expected to find a correspondence between both thermal tolerance limits (CTmax a...

In organisms such as fish, where body size is considered an important state variable for the study of their population dynamics, size-specific growth and survival rates can be influenced by local variation in both biotic and abiotic factors, but few studies have evaluated the complex relationships between environmental variability and size-dependen...

Measuring morphological disparity, an approximation to diversity, within-group variance of forms is an essential stage in order to evaluate effects of selection pressures which are acting on populations, promoting morphological differences (phenotypic plasticity), specialization or microevolutive processes.

Existen dos escenarios futuros de efectos del cambio climático sobre la biodiversidad de vertebrados: 1) Los ecosistemas se desplazan en conjunto en función del clima, y 2) Los ecosistemas se adaptan y cambian. El primero es poco realista debido a la tremenda y creciente fragmentación de hábitat en Europa y a la complejidad de las respuestas de las...

In species with simultaneous polyandry, male-biased operational sex ratio is expected to increase the risk of sperm competition and thus sperm traits affecting siring success can differ among populations. Here, we test the hypothesis that high male–female ratios will enhance sperm competitiveness of Rana temporaria males. In this species, local pop...

Seasonal time constraints can pose strong selection on life histories. Time-constrained animals should prioritise fast development over predation risk to avoid unfavourable growing conditions. However, changes in phenology could alter the balance between anti-predator and developmental needs. We studied variation of anti-predator strategies in comm...

1. As size is tightly associated with fitness, compensatory strategies for growth loss can be vital for restoring individual fitness. However, immediate and delayed costs of compensatory responses may prevent their generalization, and the optimal strategy may depend on environmental conditions. Compensatory responses may be particularly important i...

An approximation to the correlation analysis between shape and metabolic rate.

Morphological differentiation can be the result from either genetic and environmental factors, or from the interaction between both and a array of different phenotypes may be produced from a single genotype: phenotypic plasticity. Morphological disparity is caused by both genetic and environmental differences among individuals and phenotypic plasti...

Biodiversity is a reflection of genetic diversity, which is ultimately affected by a greater number of factors associated with human activity than any other level of biodiversity. The conservation of this biodiversity is therefore a main objective in the management of the natural environment. Global change is one of the major threats for biodiversi...

El estudio de las tolerancias térmicas para el examen de El estudio de las tolerancias térmicas para el examen de hipótesis biogeográficas y de la vulnerabilidad de los orga hipótesis biogeográficas y de la vulnerabilidad de los orga-nismos ante el calentamiento global. Ejemplos en anfíbios nismos ante el calentamiento global. Ejemplos en anfíbios....

Juvenile Atlantic salmon, Salmo salar, from two contrasting populations that had been reared under identical conditions differed in freshwater growth rates and the development of bimodality in length–frequency distributions. Segregation by size started at least a month earlier in the northern (River Shin, northern Scotland) than in the southern pop...

In organisms with complex life cycles, environmentally induced plasticity across sequential stages can have important consequences on morphology and life history traits such as developmental and growth rates. However, previous research in amphibians and other ectothermic vertebrates suggests that some morphological traits are generally insensitive...

The timing of many life history events shows phenotypic plasticity in response to the risk of predation. Theory predicts that increased risk of mortality in an early stage should select for switching earlier, while a higher risk after the transition should select for switching later. Here we examined the effects of stage-specific predation risk on...

Species Inhabiting habitats with different predators are expected to show divergent phenotypes for antipreciator traits. Here, we used a predator-prey system of dragonfly larvae and tadpoles to determine If vulnerability to a common predator differs in species with contrasting antipredator strategies. We examined the vulnerability of tadpoles of Ra...

Compensatory growth (CG) is a key issue in work aiming at a full understanding of the adaptive sig-nificance of growth plasticity and its carryover effects on life-history. The number of studies addressing evolutionary explanations for CG has increased rapidly during the last few years, but there has not been a parallel gain in our understanding of...

Compensatory growth (CG) is a key issue in work aiming at a full understanding of the adaptive sig-nificance of growth plasticity and its carryover effects on life-history. The number of studies addressing evolutionary explanations for CG has increased rapidly during the last few years, but there has not been a parallel gain in our understanding of...

Abstract Variations in the age structure and number of Atlantic salmon, Salmo salar L., running into the River Eo in northern Spain were assessed from catch records of sport fisheries for the period 1949 to 1991. The analysis focused on two periods (1951–1960 and 1981–1991) for which more complete data on fish number, size and age were available. O...

http://reddeparquesnacionales.mma.es/parques/rcg/documentos/resumen_10.pdf

1. To gain insight into the evolution of compensatory growth, we studied the growth patterns of anuran (Rana temporaria) larvae following either a period of exogenous growth depression (food restriction) or a period of endogenous depression (exposure to predators). We also investigated the potential deferred costs that larval compensatory growth co...

In species with complex life cycles hatching plasticity can provide an effective escape from egg predators, but theoretical studies predict a predation-risk trade-off across egg and larval stages. In this study, we examine whether the pres-ence of an egg predator can alter the timing of hatching in an anuran, Rana temp-oraria, and the consequences...

We investigated the role of constitutive morphology and previous experience in predator avoidance in two anuran species associated with different larval habitats. In Rana temporaria, deeper tails and larger body size conferred selective advantage against dragonfly predation. Previous experience with predators had a positive influence on the surviva...

Dispersal is essential for genetic flow and diversity, and can explain the spatial organization of a population. Dispersal processes are influenced by a plethora of factors acting at different spatial and temporal scales. Our main goal with this project is to explore some of those factors. We first analyse how the landscape structure affects disper...

Dispersal is essential for genetic flow and diversity, and can explain the spatial organization of a population. Dispersal processes are influenced by a plethora of factors acting at different spatial and temporal scales. Our main goal with this project is to explore some of those factors. We first analyse how the landscape structure affects disper...

Figure A1. Experimental arena used to evaluate the predator avoidance behavior of Discoglossus galganoi tadpoles in relation to food quality. The experimental trays contained "poor and safe" (P+S), and "rich and risky" (R+R) zones. In the R+R zone, larvae had full access to the food contained inside a Petri dish adjacent to a tube of plastic mesh c...

Metamorphosis can disrupt the correlation structure between juvenile and adult traits, thus allowing relatively independent evolution in contrasting environments. We used a multiple experimental approach to investigate how diet quality and larval predation risk affected the rates of growth and development in painted frogs (Discoglossus galganoi), a...

Summary 1. Adaptation to cold environments of ectotherm populations is expected to result in increased standard metabolic rates if resources are not limiting. However, it is still unclear how the maintenance of high standard metabolic rates would affect locomotor performance and its impact at the population level. 2. We compared standard metabolic...

We examined the influence of habitat size, growth opportunity, and the thermal conditions experienced during early development on the standard metabolic rate (SMR) of juvenile brown trout (Salmo trutta) from six natural populations to contrast the hypothesis of countergradient selection in metabolic rate. The study populations differed significantl...

This study assesses the influence of thermal regime on the development, survival rates and early growth of embryos of sea lamprey Petromyzon marinus incubated at five constant temperatures (7, 11, 15, 19 and 23° C). The time from fertilization to 50% hatching and from hatching to 50% burrowing were inversely related to incubation temperature. All t...

Both in foraging groups and in a sequential prey encounter context, learning had a visible effect on the pattern of selection for three live prey types (Ecdyonurus larvae, Hydropsyche larvae, and Gammarus) by juvenile Atlantic salmon Salmo salar. Compared to wild-caught fish, naive, hatchery-reared fish that had not been exposed to natural prey ate...

Compensatory growth is an organism's reaction to buffer deviations from targeted trajectories. We explored the compensatory patterns of juvenile brown trout under field and laboratory conditions. Divergence of size and condition trajectories was induced by manipulating food levels in the laboratory and then releasing the trout into a river. In the...

In salmonids, there seems to be a positive correlation between standard metabolic rate and growth rate under artificial rearing conditions. Several recent studies have suggested that phenotypic correlations between physiological or behavioural traits and developmental or life history responses might be common when assayed in low-complexity habitats...