Variation In Life-history Traits Research Articles

Implication of five host plants on the life history trait of Tetranychus urticae (Acari: Tetranychidae)

The two-spotted spider mite, Tetranychus-urticae is one of the most damaging polyphagous pests in India. The life history of mated and unmated females of T. urticae was studied on five important host plants namely, Justicia-adhatoda L. (Malabar nut), Wissadula-periplocifolia (L.) Thwaites-(white velvet leaf),-Citrus limon (L.) Osbeck (lemon), Mangifera indica L. (mango) and Syzygium jambolanum (Lam.) DC (water apple), under controlled laboratory conditions at 25 ± 5 °C, 65 ± 5% relative humidity (RH) and photoperiod of 12:12 (L:D). Results revealed no significant variation in life history traits of mated and unmated females of T. urticae on the tested host plants. In contrast only the fecundity and hatchability of mated and unmated females were proved different on different host plants. We, therefore, infer that all the tested host plants provide suitable resource for successful completion of life history of T. urticae. Interestingly, we recorded highest daily and total fecundity rate on M. indica and that suggests preference of two spotted spider mite for mango over other tested host pant. Overall, we can infer that T. urticae can be considered as potential polyphagous pest which could pose serious threat to different crops, fruits and vegetables on which they thrive successfully.

Stochastic phenotypic variation: empirical results and potential use in Eurytemora research (Copepoda, Calanoida)

Abstract This study analyses the potential of stochastic phenotypic variation for investigating the population biology of Eurytemora. Stochastic variation is the third component of phenotypic variance, standing on equal footing with genotypic variation and phenotypic plasticity. This is a manifestation of developmental instability and usually increases under stress. In morphological traits, stochastic variation is most often studied using fluctuating asymmetry (FA) of bilateral traits. Here, using data on the FA of nine populations of three Eurytemora species from Europe and North America, we found no correlation between FA and temperature, salinity or tidal amplitude. Invasive American E. carolleeae in the Gulf of Finland (Baltic Sea) had lower FA than the same species in its native Chesapeake Bay, or than E. affinis in its native Gulf of Finland. This pattern may be caused by global warming, which brought Chesapeake Bay temperatures beyond E. carolleeae’s optimal conditions, but made the Gulf of Finland a more suitable environment. Stochastic variation in life history traits is technically more difficult to study, but it may provide important information on fitness. In particular, it manifests in bet-hedging, a risk-spreading strategy beneficial in unpredictable environments. As resting eggs are common in Eurytemora, bet-hedging can be considered a genus strategy. Understanding how stochastic variation contributes to total phenotypic variance may help to interpret changes under unpredictable environmental conditions. Therefore, studies of stochastic phenotypic variation may supply information about the population biology of Eurytemora and other copepods.

Determinants of genetic variation across eco-evolutionary scales in pinnipeds.

The effective size of a population (Ne), which determines its level of neutral variability, is a key evolutionary parameter. Ne can substantially depart from census sizes of present-day breeding populations (NC) as a result of past demographic changes, variation in life-history traits and selection at linked sites. Using genome-wide data we estimated the long-term coalescent Ne for 17 pinniped species represented by 36 population samples (total n = 458 individuals). Ne estimates ranged from 8,936 to 91,178, were highly consistent within (sub)species and showed a strong positive correlation with NC ([Formula: see text] = 0.59; P = 0.0002). Ne/NC ratios were low (mean, 0.31; median, 0.13) and co-varied strongly with demographic history and, to a lesser degree, with species' ecological and life-history variables such as breeding habitat. Residual variation in Ne/NC, after controlling for past demographic fluctuations, contained information about recent population size changes during the Anthropocene. Specifically, species of conservation concern typically had positive residuals indicative of a smaller contemporary NC than would be expected from their long-term Ne. This study highlights the value of comparative population genomic analyses for gauging the evolutionary processes governing genetic variation in natural populations, and provides a framework for identifying populations deserving closer conservation attention.

Food dependent changes of the life history traits of Catopsilia pyranthe (Lepidoptera: Pieridae)

ABSTRACT The effect of larval feeding on the life history traits of the mottled emigrant butterfly Catopsilia pyranthe (Linnaeus, 1758) (Lepidoptera: Pieridae) was assessed to link life history variations as a function of food availability. The 0-day-old larvae of C. pyranthe were reared with varying quantity of food (100, 200, 400, 800, 1600 and 3200 mg/day) against a control set with ad libitum food availability. Significant differences in instar duration and body weight of the larva and therefore fitness were found in relation to the amount of food available. In urban regions like Kolkata, India, disparity in food availability may induce variations in life history traits and thus fitness and survival in C. pyranthe.

Developmental life history is associated with variation in rates of climatic niche evolution in a salamander adaptive radiation.

Rates of climatic niche evolution vary widely across the tree of life and are strongly associated with rates of diversification among clades. However, why the climatic niche evolves more rapidly in some clades than others remains unclear. Variation in life history traits often plays a key role in determining the environmental conditions under which species can survive, and therefore, could impact the rate at which lineages can expand in available climatic niche space. Here, we explore the relationships among life-history variation, climatic niche breadth, and rates of climatic niche evolution. We reconstruct a phylogeny for the genus Desmognathus, an adaptive radiation of salamanders distributed across eastern North America, based on nuclear and mitochondrial genes. Using this phylogeny, we estimate rates of climatic niche evolution for species with long, short, and no aquatic larval stage. Rates of climatic niche evolution are unrelated to the mean climatic niche breadth of species with different life histories. Instead, we find that the evolution of a short larval period promotes greater exploration of climatic space, leading to increased rates of climatic niche evolution across species having this trait. We propose that morphological and physiological differences associated with variation in larval stage length underlie the heterogeneous ability of lineages to explore climatic niche space. Rapid rates of climatic niche evolution among species with short larval periods were an important dimension of the clade's adaptive radiation and likely contributed to the rapid rate of lineage accumulation following the evolution of an aquatic life history in this clade. Our results show how variation in a key life-history trait can constrain or promote divergence of the climatic niche, leading to variation in rates of climatic niche evolution among species.

Mitochondria as central characters in a complex narrative: Linking genomics, energetics, pace-of-life, and aging in natural populations of garter snakes.

As a pacesetter for physiological processes, variation in metabolic rate can determine the shape of energetic trade-offs and thereby drive variation in life-history traits. In turn, such variation in metabolic performance and life-histories can have profound consequences for lifespan and lifetime fitness. Thus, the extent to which metabolic rate variation is due to phenotypic plasticity or fixed genetic differences among individuals or populations is likely to be shaped by natural selection. Here, we first present a generalized framework describing the central role of mitochondria in processes linking environmental, genomic, physiological, and aging variation. We then present a test of these relationships in an exemplary system: populations of garter snakes (Thamnophis elegans) exhibiting contrasting life-history strategies - fast-growing, early-reproducing, and fast-aging (FA) versus slow-growing, late-reproducing, and slow-aging (SA). Previous work has characterized divergences in mitochondrial function, reactive oxygen species processing, and whole-organism metabolic rate between these contrasting life-history ecotypes. Here, we report new data on cellular respiration and mitochondrial genomics and synthesize these results with previous work. We test hypotheses about the causes and implications of mitochondrial genome variation within this generalized framework. First, we demonstrate that snakes of the FA ecotype increase cellular metabolic rate across their lifespan, while the opposite pattern holds for SA snakes, implying that reduced energetic throughput is associated with a longer life. Second, we show that variants in mitochondrial genomes are segregating across the landscape in a manner suggesting selection on the physiological consequences of this variation in habitats varying in temperature, food availability, and rates of predation. Third, we demonstrate functional variation in whole-organism metabolic rate related to these mitochondrial genome sequence variants. With this synthesis of numerous datasets, we are able to further characterize how variation across levels of biological organization interact within this generalized framework and how this has resulted in the emergence of distinct life-history ecotypes that vary in their rates of aging and lifespan.

Diversity of bacteria associated with Hormaphidinae aphids (Hemiptera: Aphididae).

Bacteria are ubiquitous inhabitants of animals. Hormaphidinae is a particular aphid group exhibiting very diverse life history traits. However, the microbiota in this group is poorly known. In the present study, using high‐throughput sequencing of bacterial 16S ribosomal RNA gene amplicons, we surveyed the bacterial flora in hormaphidine aphids and explored whether the aphid tribe, host plant and geographical distribution are associated with the distribution of secondary symbionts. The most dominant bacteria detected in hormaphidine species are heritable symbionts. As expected, the primary endosymbiont Buchnera aphidicola is the most abundant symbiont across all species and has cospeciated with its host aphids. Six secondary symbionts were detected in Hormaphidinae. Arsenophonus is widespread in Hormaphidinae species, suggesting the possibility of ancient acquisition of this symbiont. Ordination analyses and statistical tests show that the symbiont composition does not seem to relate to any of the aphid tribes, host plants or geographical distributions, which indicate that horizontal transfers might occur for these symbionts in Hormaphidinae. Correlation analysis exhibits negative interference between Buchnera and coexisting secondary symbionts, while the interactions between different secondary symbionts are complicated. These findings display a comprehensive picture of the microbiota in Hormaphidinae and may be helpful in understanding the symbiont diversity within a group of aphids.

No change in Atlantic Yellow-nosed Albatross (Thalassarche chlororhynchos) egg size over 160 years

ABSTRACT Biotic and abiotic conditions in the world’s oceans have changed considerably in the last two centuries as a result of anthropogenic factors, including whaling, sealing, fishing, and climate change. For species that have limited variation in life-history traits, life-history characteristics may impede the ability to adapt to changing environmental conditions. Albatrosses are one such group, where breeding investment is limited to a single egg every one or two years. At a coarse level, individuals may decide whether to breed or not, or whether to incubate an egg or not, but one of the only finer-scale adjustment in parental investment involves altering egg size, along with parental foraging and chick provisioning. We investigated changes in egg size in Atlantic Yellow-nosed Albatrosses (Thalassarche chlororhynchos) breeding at Tristan da Cunha, South Atlantic Ocean, from 1856 to 2015. We found no change in egg length, or breadth, which may suggest that with regards to this life-history parameter, Atlantic Yellow-nosed Albatrosses appear to have been able to buffer the effects of the trophic, climatic and oceanographic changes in the South Atlantic Ocean.

Loss of Habitat Leads to Bigger Toads and Bigger Eggs: Natural Area Management Predictions for the Eastern American Toad, Anaxyrus americanus americanus (Holbrook, 1836)

Reproductive characteristics of the Eastern American Toad (Anaxyrus americanus americanus) vary geographically across its broad eastern North American range. Northern populations are known to breed for a shorter period that begins later in the season (April and/or May) than southern populations that can begin in winter and last until April. Delayed maturity and larger minimum body size are also associated with northern populations. Specimens collected during two years of systematic trapping during 1982–1983 at the Powdermill Nature Reserve (PNR), Westmoreland County, Pennsylvania, were examined to test predictions of geographic patterns associated with reproduction and growth of a southwestern Pennsylvania population. The results indicate a short egg laying season in May, large adult body size, and delayed maturity. An apparent response to northern Allegheny climate, the reproductive-related patterns of this population were similar to those of other northern regions rather than populations at similar latitudes within Pennsylvania. Eastern American Toads collected from a breeding site at PNR in 2014 were larger in body size, clutch size, and egg size than those of the 1982–1983 study. Most notably, loss of open breeding habitat in the 30+ years between sampling periods resulted in fewer larger toads producing on average larger eggs and twice the clutch size than counterparts studied during earlier successional series of this study site. These differences quantify geographic and temporal variability in life history traits of an ecologically versatile and geographically widespread species and provide landscape-wide predictions of life history responses by the Eastern American Toad to natural or human-mediated changes to natural areas.

Isolation and predation drive gecko life-history evolution on islands

AbstractInsular animals are thought to be under weak predation pressure and increased intraspecific competition compared with those on the mainland. Thus, insular populations are predicted to evolve ‘slow’ life histories characterized by fewer and smaller clutches of larger eggs, a pattern called the ‘island syndrome’. To test this pattern, we collected data on egg volume, clutch size and laying frequency of 31 Aegean Island populations of the closely related geckos of the Mediodactylus kotschyi species complex. We tested how predation pressure, resource abundance, island area and isolation influenced reproductive traits. Isolation and predation were the main drivers of variation in life-history traits. Higher predator richness seemed to promote faster life histories, perhaps owing to predation on adults, whereas the presence of boas promoted slower life histories, perhaps owing to release from predation by rats on the eggs of geckos. Insular geckos followed only some of the predictions of the ‘island syndrome’. Predation pressure seemed to be more complex than expected and drove life histories of species in two opposing directions. Our results highlight the importance of considering the identity of specific predators in ecological studies.

Evidence for family-level variation of phenotypic traits in response to temperature of Brazilian Nyssorhynchus darlingi

BackgroundNyssorhynchus darlingi (also known as Anopheles darlingi) is the primary malaria vector in the Amazon River Basin. In Brazil, analysis of single nucleotide polymorphisms (SNPs) previously detected three major population clusters, and a common garden experiment in a laboratory setting revealed significant population variation in life history traits. Increasing temperatures and local level variation can affect life history traits, i.e. adult longevity, that alter vectorial capacity with implications for malaria transmission in Ny. darlingi.MethodsWe investigated the population structure of Ny. darlingi from 7 localities across Brazil utilizing SNPs and compared them to a comprehensive Ny. darlingi catalog. To test the effects of local level variation on life history traits, we reared F1 progeny from the 7 localities at three constant temperatures (20, 24 and 28 °C), measuring key life history traits (larval development, food-starved adult lifespan, adult size and daily survival).ResultsUsing nextRAD genotyping-by-sequencing, 93 of the field-collected Ny. darlingi were genotyped at 33,759 loci. Results revealed three populations (K = 3), congruent with major biomes (Amazonia, Cerrado and Mata Atlântica), with greater FST values between biomes than within. In the life history experiments, increasing temperature reduced larval development time, adult lifespan, and wing length in all localities. The variation of family responses for all traits within four localities of the Amazonia biome was significant (ANOVA, P < 0.05). Individual families within localities revealed a range of responses as temperature increased, for larval development, adult lifespan, wing length and survival time.ConclusionsSNP analysis of several Brazilian localities provided results in support of a previous study wherein populations of Ny. darlingi were clustered by three major Brazilian biomes. Our laboratory results of temperature effects demonstrated that population variation in life history traits of Ny. darlingi exists at the local level, supporting previous research demonstrating the high plasticity of this species. Understanding this plasticity and inherent variation between families of Ny. darlingi at the local level should be considered when deploying intervention strategies and may improve the likelihood of successful malaria elimination in South America.

Variations in seasonal (not mean) temperatures drive rapid adaptations to novel environments at a continent scale.

The recent development of human societies has led to major, rapid, and often inexorable changes in the environment of most animal species. Over the last decades, a growing number of studies formulated predictions on the modalities of animal adaptation to novel or changing environments, questioning how and at what speed animals should adapt to such changes, discussing the levels of risks imposed by changes in the mean and/or variance of temperatures on animal performance, and exploring the underlying roles of phenotypic plasticity and genetic inheritance. These fundamental predictions, however, remain poorly tested using field data. Here, we tested these predictions using a unique continental-scale data set in the European earwig Forficula auricularia L., a univoltine insect introduced in North America one century ago. We conducted a common garden experiment, in which we measured 13 life-history traits in 4,158 field-sampled earwigs originating from 19 populations across North America. Our results first demonstrate that 10 of the 13 measured life-history traits are associated with two sets of variations in seasonal temperatures, that is, winter-summer and autumn-spring. We found, however, no association with the overall mean monthly temperatures of the invaded locations. Furthermore, our use of a common garden setup reveals that the observed patterns of variation in earwigs' life-history traits are not mere plastic responses to their current environment, but are either due to their genetic background and/or to the environmental conditions they experienced during early life development. Overall, these findings provide continent-scale support to the claims that adaptation to thermal changes can occur quickly (in less than 100 generations), even in insects with long life cycles, and emphasize the importance of variation in seasonal temperature over mean population temperatures in climate adaptation.

Negative frequency dependent selection contributes to the maintenance of a global polymorphism in mitochondrial DNA

BackgroundUnderstanding the forces that maintain diversity across a range of scales is at the very heart of biology. Frequency-dependent processes are generally recognized as the most central process for the maintenance of ecological diversity. The same is, however, not generally true for genetic diversity. Negative frequency dependent selection, where rare genotypes have an advantage, is often regarded as a relatively weak force in maintaining genetic variation in life history traits because recombination disassociates alleles across many genes. Yet, many regions of the genome show low rates of recombination and genetic variation in such regions (i.e., supergenes) may in theory be upheld by frequency dependent selection.ResultsWe studied what is essentially a ubiquitous life history supergene (i.e., mitochondrial DNA) in the fruit fly Drosophila subobscura, showing sympatric polymorphism with two main mtDNA genotypes co-occurring in populations world-wide. Using an experimental evolution approach involving manipulations of genotype starting frequencies, we show that negative frequency dependent selection indeed acts to maintain genetic variation in this region. Moreover, the strength of selection was affected by food resource conditions.ConclusionsOur work provides novel experimental support for the view that balancing selection through negative frequency dependency acts to maintain genetic variation in life history genes. We suggest that the emergence of negative frequency dependent selection on mtDNA is symptomatic of the fundamental link between ecological processes related to resource use and the maintenance of genetic variation.

Geographic variation in life-history traits of the long-lived monacanthid Meuschenia scaber (Monacanthidae)

Demography and life-history characteristics of reef fishes may vary as a consequence of ecological and environmental factors that lead to changes among populations. We evaluated variation in life-history traits in the leatherjacket Meuschenia scaber (Monacanthidae) through age-based analysis of 2112 fish collected from three locations in New Zealand distributed along an 8° latitudinal and 5 °C SST gradients. Meuschenia scaber showed distinct differences in age structure, growth patterns, maximum size and age, sex ratio and mortality across this latitudinal gradient. At warmer lower latitudes (Hauraki Gulf) the population displayed significantly greater mean adult body size (Lmax) and asymptotic length (L∞) in comparison with the other two locations. Fish from Tasman Bay (mid-range latitude) had a longer life span (Tmax) and a maximum age of 19 years, which represents the longest-lived monacanthid documented to date. Fish from Pegasus Bay (cooler higher latitude) showed a slower initial growth than lower latitude counterparts. The difference in maximum age between the sexes declined clinally from 7 years in the Hauraki Gulf to 3 years in Tasman Bay and 1 year in Pegasus Bay. Meuschenia scaber females tended to display heavier and larger body size than males at all three locations. Sex ratios varied among populations and with depth, suggesting females in the Hauraki Gulf and Tasman Bay may move into deeper water with age. Given the increasing global exploitation of monacanthids in multispecies fisheries and their long-living nature, our results provide valuable age-based demographic information essential for future conservation, monitoring and management programs.

Toward a metabolic theory of life history

The life histories of animals reflect the allocation of metabolic energy to traits that determine fitness and the pace of living. Here, we extend metabolic theories to address how demography and mass-energy balance constrain allocation of biomass to survival, growth, and reproduction over a life cycle of one generation. We first present data for diverse kinds of animals showing empirical patterns of variation in life-history traits. These patterns are predicted by theory that highlights the effects of 2 fundamental biophysical constraints: demography on number and mortality of offspring; and mass-energy balance on allocation of energy to growth and reproduction. These constraints impose 2 fundamental trade-offs on allocation of assimilated biomass energy to production: between number and size of offspring, and between parental investment and offspring growth. Evolution has generated enormous diversity of body sizes, morphologies, physiologies, ecologies, and life histories across the millions of animal, plant, and microbe species, yet simple rules specified by general equations highlight the underlying unity of life.

Phenotypic variation of life-history traits in native, invasive, and landrace populations of Brassica tournefortii.

Varying environments can result in different patterns of adaptive phenotypes. By performing a common greenhouse experiment, we identified phenotypic differentiation on phenology, leaf morphology, branch architecture, size, and reproduction, among native, invasive, and landrace ranges of Brassica tournefortii. We first compared trait means and fitness functions among ranges, then we analyzed how trait means and selection strength of populations respond to varying aridity. Most traits varied such that landrace > invasive > native. Excluding reproduction, which was positively selected, most trait PCs experienced nonlinear selection in the native range but frequently shifted to directional selection in invasive and/or landrace ranges. The absence of strong clines for trait means in landrace and invasive populations suggest that agricultural practices and novel environments in source locations affected adaptive potential. Selection strength on faster reproductive phenology (negative directional) and leaf margin trait (disruptive) PCs coincided with increasing moisture. In native populations, higher aridity was associated with more days to reproduction, but landrace and invasive populations show stable mean time to reproduction with increasing moisture. A stable adaptive trait can increase range expansion in the invasive range, but stability can be beneficial for future harvest of B. tournefortii seed crops in the face of climate change.

A Genome-Wide Approach to the Phylogeography of the Mussel Mytilus galloprovincialis in the Adriatic and the Black Seas

Connectivity between populations shapes the genetic structure of species being crucial for an effective management of environmental resources. Genetic approaches can provide indirect measures of connectivity, allowing the identification of genetically differentiated - unconnected - populations. In this study, we applied a 2b-RAD approach based on hundreds of polymorphic loci to provide the first detailed insight into the population genomics of the Mediterranean mussel Mytilus galloprovincialis in part of its native geographical range. We sampled 19 localities within the Mediterranean and Black Seas, and analyzed a total of 478 samples. We detected strong differences between the two seas, whereas no differences were found between samples from the Western and Central Mediterranean and within Western Mediterranean samples. In the Central Mediterranean a significant differentiation emerged comparing Central Adriatic samples with those from South Adriatic and Ionian Seas. Furthermore, an East-to-West genetic structuring was found in the Central Adriatic Sea, which was not present in the Southern Adriatic and Ionian Seas. These results possibly reflect the local oceanography, with a Middle Adriatic gyre unable to prevent genetic differentiation in this species, and a Southern Adriatic gyre that effectively mixes propagules in Southern areas. In the Black Sea, no signal of genetic structure was found, although samples were spaced at similar distances as in the Adriatic-Ionian area. Genetic connectivity patterns of M. galloprovincialis reveal peculiar species-specific features respect to other species with similar larval duration, suggesting caution in using genetic connectivity data of single species in defining conservation units. We recommend of using genetic connectivity data of many species representing a variety of life history traits, and we call for new investigations using high resolution population genomics, particularly in the Black Sea, to understand if areas separated by hundreds of kilometers can be considered genetically connected as mussels’ data suggest. This information will be critical to ensure “a well-connected system of protected areas” according to Aichi Target 11 of the Convention on Biological Diversity.

Heritability and genetic correlations of personality, life history and morphology in the grey mouse lemur (Microcebus murinus).

The recent interest in animal personality has sparked a number of studies on the heritability of personality traits. Yet, how the sources variance these traits can be decomposed remains unclear. Moreover, whether genetic correlations with life-history traits, personality traits and other phenotypic traits exist as predicted by the pace-of-life syndrome hypothesis remains poorly understood. Our aim was to compare the heritability of personality, life-history and morphological traits and their potential genetic correlations in a small primate (Microcebus murinus). We performed an animal model analysis on six traits measured in a large sample of captive mouse lemurs (N = 486). We chose two personality traits, two life-history traits and two morphological traits to (i) estimate the genetic and/or environmental contribution to their variance, and (ii) test for genetic correlations between these traits. We found modest narrow-sense heritability for personality traits, morphological traits and life-history traits. Other factors including maternal effects also influence the sources of variation in life-history and morphological traits. We found genetic correlations between emergence latency on the one hand and radius length and growth rate on the other hand. Emergence latency was also genetically correlated with birth weight and was influenced by maternal identity. These results provide insights into the influence of genes and maternal effects on the partitioning of sources of variation in personality, life-history and morphological traits in a captive primate model and suggest that the pace-of-life syndrome may be partly explained by genetic trait covariances.

SalMotifDB: a tool for analyzing putative transcription factor binding sites in salmonid genomes

BackgroundRecently developed genome resources in Salmonid fish provides tools for studying the genomics underlying a wide range of properties including life history trait variation in the wild, economically important traits in aquaculture and the evolutionary consequences of whole genome duplications. Although genome assemblies now exist for a number of salmonid species, the lack of regulatory annotations are holding back our mechanistic understanding of how genetic variation in non-coding regulatory regions affect gene expression and the downstream phenotypic effects.ResultsWe present SalMotifDB, a database and associated web and R interface for the analysis of transcription factors (TFs) and their cis-regulatory binding sites in five salmonid genomes. SalMotifDB integrates TF-binding site information for 3072 non-redundant DNA patterns (motifs) assembled from a large number of metazoan motif databases. Through motif matching and TF prediction, we have used these multi-species databases to construct putative regulatory networks in salmonid species. The utility of SalMotifDB is demonstrated by showing that key lipid metabolism regulators are predicted to regulate a set of genes affected by different lipid and fatty acid content in the feed, and by showing that our motif database explains a significant proportion of gene expression divergence in gene duplicates originating from the salmonid specific whole genome duplication.ConclusionsSalMotifDB is an effective tool for analyzing transcription factors, their binding sites and the resulting gene regulatory networks in salmonid species, and will be an important tool for gaining a better mechanistic understanding of gene regulation and the associated phenotypes in salmonids. SalMotifDB is available at https://salmobase.org/apps/SalMotifDB.

Demographic and life history variation in two sky‐island populations of an endangered alpine lizard

AbstractA species’ life history is a strong determinant of its risk of extinction; traits such as body size, growth rate, age at maturity and fecundity influence population viability and persistence, as well as capacity for dispersal and colonisation of new habitats. Yet, despite the potential for substantial geographic variation in life history, most conservation programmes rely upon the species average rather than information specific to individual populations. We use the Guthega Skink (Liopholis guthega), a threatened alpine endemic lizard restricted to two geographically isolated locations in south‐eastern Australia, as a case study to demonstrate how geographic variation in life history traits may better inform conservation management. Liopholis guthega has a relatively short life span, with only a few years of reproductive activity, inter‐annual variation in reproductive output, and less‐than‐annual reproduction. We show that the Victorian population has a significantly slower growth rate, attains a smaller maximum size, reaches reproductive maturity later, and produces significantly smaller litters, despite no difference in longevity suggesting that it may be more vulnerable to extinction. We, therefore, suggest evaluating genetic rescue from the New South Wales population to improve recruitment and longevity of Victorian L. guthega, ongoing population monitoring in both locations, and a dedicated pest control programme to reduce pressure on this population. Our study has far reaching impacts; primarily demonstrating how knowledge of geographic variation in life history has the potential to improve conservation management of threatened species.