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Results for “Ecology and Evolution”

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USGS2002

Collaborative approaches to the evolution of migration and the development of science-based conservation in shorebirds

Shorebirds are among the most highly migratory creatures on earth. Both the study of their ecology and ongoing efforts to conserve their populations must reflect this central aspect of their biology. Many species of shorebirds use migration and staging sites scattered throughout the hemisphere to complete their annual migrations between breeding areas and nonbreeding habitats (Morrison 1984). The vast distances between habitats they use pose significant challenges for studying their migration ecology. At the same time, the large number of political boundaries shorebirds cross during their epic migrations create parallel challenges for organizations working on their management and conservation. Nebel et al. (2002) represent a collaborative effort to understand the conservation implications of Western Sandpiper ( Calidris mauri ) migration ecology on a scale worthy of this highly migratory species. The data sets involved in the analysis come from four U.S. states, two Canadian provinces, and a total of five nations. Only by collaborating on this historic scale were the authors able to assemble the information necessary to understand important aspects of the migration ecology of this species, and the implications for conservation of the patterns they discovered. Collaborative approaches to shorebird migration ecology developed slowly over several decades. The same period also saw the creation of large-scale efforts to monitor and conserve shorebirds. This overview first traces the history of the study of migration ecology of shorebirds during that fertile period, and then describes the monitoring and protection efforts that have been developed in an attempt to address the enormous issues of scale posed by shorebird migration ecology and conservation.

The Auk↗

USGS2023

A reference genome assembly for the continentally distributed ring-necked snake, Diadophis punctatus

Snakes in the family Colubridae include more than 2,000 currently recognized species, and comprise roughly 75% of the global snake species diversity on Earth. For such a spectacular radiation, colubrid snakes remain poorly understood ecologically and genetically. Two subfamilies, Colubrinae (788 species) and Dipsadinae (833 species), comprise the bulk of colubrid species richness. Dipsadines are a speciose and diverse group of snakes that largely inhabit Central and South America, with a handful of small-body-size genera that have invaded North America. Among them, the ring-necked snake, Diadophis punctatus , has an incredibly broad distribution with 14 subspecies. Given its continental distribution and high degree of variation in coloration, diet, feeding ecology, and behavior, the ring-necked snake is an excellent species for the study of genetic diversity and trait evolution. Within California, six subspecies form a continuously distributed “ring species” around the Central Valley, while a seventh, the regal ring-necked snake, Diadophis punctatus regalis is a disjunct outlier and Species of Special Concern in the state. Here, we report a new reference genome assembly for the San Diego ring-necked snake, D. p. similis , as part of the California Conservation Genomics Project. This assembly comprises a total of 444 scaffolds spanning 1,783 Mb and has a contig N50 of 8.0 Mb, scaffold N50 of 83 Mb, and BUSCO completeness score of 94.5%. This reference genome will be a valuable resource for studies of the taxonomy, conservation, and evolution of the ring-necked snake across its broad, continental distribution.

Journal of Heredity↗

USGS2025

Long‐term effects of low‐drop grade control structures on channel evolution in the Yazoo River Basin

Channel incision is a widespread problem, especially in river basins that have an extensive history of channel alterations. Because channel incision causes large ecological and economic consequences, the prevention of continued migration of headcuts, defined as a steep change in stream gradient over a short reach, has been the focus of many stream engineering projects. Low-drop grade control structures (GCS) are a type of structure installed to halt the upstream movement of a headcut and were widely installed in the rivers and streams of the Yazoo River Basin in northern Mississippi. The goal of this study was to evaluate the long-term effects of these structures 30+ years post installation. To assess GCS effects on channel morphology, stream cross-section surveys were used to calculate Bank Height Ratio, Width-to-Depth Ratio, and Entrenchment Ratio, while point estimates made along each transect were used to calculate the average sediment size distribution for each of 30 sites. Analyses revealed that the GCS were successful in checking channel incision moving headward in the streams: sites upstream of the GCS were less incised and had greater accumulations of fine substrates compared to sites downstream and sites on streams lacking erosion control structures. Given the widespread use of GCS, these results can inform efforts aimed at managing channel incision.

Mississippi↗

USGS2015

Barrier Island Shorelines Extracted from Landsat Imagery

Introduction Changes to barrier islands occur at time scales that vary from the few hours it takes an individual storm to pass (Morton, 2008) to the millennia it takes for coastal systems to undergo geologic evolution. Developing an understanding of how barrier islands will respond to climate change, sea level rise, and major storms over a range of time scales is relevant to studies of physical, geological, ecological, and societal processes and will help to guide and improve management of our coastal resources (Sallenger and others, 1987). Observations of coastal processes made over a range of spatial and temporal scales and from a variety of instrument platforms (for example, in situ and remote remote sensing) are required to understand and eventually predict the evolution of coastal systems. The deployment of Landsat and other earth-observing satellites within the last few decades has provided an opportunity to observe barrier islands at frequent intervals, often many times a year. This sample frequency is much higher and the spatial coverage much greater than most routine high-resolution topographic surveys (Guy and others, 2014). In addition, the historical record of these datasets have become long enough to document shorter- (that is, annual) and longer-term (that is, decadal) changes from a single data source. Certain aspects of barrier island morphology, such as island size, shape, and position, can be determined from these images and can indicate erosion, land loss, and island breakup (McBride and others, 1989; Plant and Guy, 2013). The shoreline is a common variable used as a metric for coastal erosion or change (Himmelstoss and others, 2010). Although shorelines are often extracted from topographic data (for example, ground-based surveys and light detection and ranging [lidar]), image-based shorelines, corrected for their inherent uncertainties (Moore and others, 2006), have provided much of our understanding of long-term shoreline change because they pre-date routine lidar elevation survey methods. Image-based shorelines continue to be valuable because of their higher temporal resolution compared to costly airborne lidar surveys. A method for extracting sandy shorelines from 30-meter (m) resolution Landsat imagery is presented here.

Open-File Report↗

USGS2023

Fluvial delivery and wave resuspension of sediment in a sheltered, urbanized Pacific Northwest estuary

The sequence and timing of sediment delivery and redistribution in coastal systems is important for shoreline stability, ecosystem services, and remediation planning. In temperate estuaries, understanding the role of fluvial sediment delivery and dispersal relative to wind and wave remobilization processes is particularly important to address the fate of contaminants, many of which adsorb to fine particles, and to assess changes in coastal systems under projected changes in climate. Here we present an integrated analysis of observations at multiple timescales to evaluate sediment dynamics and the sedimentary coupling between fluvial and oceanographic processes within Bellingham Bay, Washington, USA, an urban estuary. Time-series data of currents, waves, and turbidity at four moorings along with geochemical data from grab samples and cores of seabed sediment from across the bay are contrasted with the dynamics of the Nooksack River, its fluvial sediment source. Even during large (5-yr return interval) river-flood events, water-column suspended-sediment concentration (SSC) near the bed on the outer delta topset was not correlated with Nooksack River runoff and was instead closely correlated with local wind-wave height. In contrast, near-surface SSC was strongly correlated with fluvial discharge, suggesting intense water-column suspended-sediment stratification during flood events. Grain-size and geochemical ( 7 "> 7 Be and excess 210 "> 210 Pb) results from seabed-sediment samples and historical bathymetric measurements of the subaqueous Nooksack River delta reveal spatial gradients of fluvial and wave influence and sediment-accumulation rates. Analysis of historical bathymetric surveys of the Nooksack River delta combined with the geochemical data reveal that about 75% of the fluvial sediment load can be accounted for in the Bellingham Bay receiving system. Studies of this type in urbanized coastal settings can help address ecological and geological questions regarding the risks from contaminants associated with fine-grained sediment, predict longer-term delta morphological evolution, and inform managers planning future coastal restoration efforts

Washington↗

USGS2024

High-quality, chromosome-level reference genomes of the viviparous Caribbean skinks Spondylurus nitidus and S. culebrae

New World mabuyine skinks are a diverse radiation of morphologically cryptic lizards with unique reproductive biologies. Recent studies examining population-level data (morphological, ecological, and genomic) have uncovered novel biodiversity and phenotypes, including the description of dozens of new species and insights into the evolution of their highly complex placental structures. Beyond the potential for this diverse group to serve as a model for the evolution of viviparity in lizards, much of the taxonomic diversity is concentrated in regions experiencing increasing environmental instability from climate and anthropogenic change. Consequently, a better understanding of genome structure and diversity will be an important tool in the adaptive management and conservation of this group. Skinks endemic to Caribbean islands are particularly vulnerable to global change with several species already considered likely extinct and several remaining species either endangered or threatened. Combining PacBio long-read sequencing, Hi-C, and RNAseq data, here we present the first genomic resources for this group by describing new chromosome-level reference genomes for the Puerto Rican Skink Spondylurus nitidus and the Culebra Skink S. culebrae . Results indicate two high quality genomes, both ∼1.4 Gb, assembled nearly telomere to telomere with complete mitochondrion assembly and annotation.

Genome Biology and Evolution↗

USGS2018

Associations of stream geomorphic conditions and prevalence of alternative reproductive tactics among sockeye salmon populations

In many species, males may exhibit alternative life histories to circumvent the costs of intrasexual competition and female courtship. While the evolution and underlying genetic and physiological mechanisms behind alternative reproductive tactics are well studied, there has been less consideration of the ecological factors that regulate their prevalence. Here, we examine six decades of age composition records from thirty‐six populations of sockeye salmon ( Oncorhynchus nerka ) to quantify associations between spawning habitat characteristics and the prevalence of precocious sneakers known as ‘jacks’. Jack prevalence was independent of neutral genetic structure among stream populations, but varied among habitat types and as a function of continuous geomorphic characteristics. Jacks were more common in streams relative to beaches and rivers, and their prevalence was negatively associated with stream width, depth, elevation, slope and area, but positively related to bank cover. Behavioural observations showed that jacks made greater use of banks, wood and shallows than guard males, indicating that their reproductive success depends on the availability of such refuges. Our results emphasize the role of the physical habitat in shaping reproductive tactic frequencies among populations, likely through local adaptation in response to variable fitness expectations under different geomorphic conditions.

Journal of Evolutionary Biology↗

USGS2020

Nanopore amplicon sequencing reveals molecular convergence and local adaptation of rhodopsin in Great Lakes salmonids

Local adaptation can drive diversification of closely related species across environmental gradients and promote convergence of distantly related taxa that experience similar conditions. We examined a potential case of adaptation to novel visual environments in a species flock (Great Lakes salmonids, genus Coregonus ) using a new amplicon genotyping protocol on the Oxford Nanopore Flongle and MinION. We sequenced five visual opsin genes for individuals of C. artedi , C. hoyi , C. kiyi , and C. zenithicus. Comparisons revealed species-specific differences in a key spectral tuning amino acid in rhodopsin (Tyr261Phe substitution), suggesting local adaptation of C. kiyi to the blue-shifted depths of Lake Superior. Ancestral state reconstruction demonstrates that parallel evolution and “toggling” at this amino acid residue has occurred several times across the fish tree of life, resulting in identical changes to the visual systems of distantly related taxa across replicated environmental gradients. Our results suggest that ecological differences and local adaptation to distinct visual environments are strong drivers of both evolutionary parallelism and diversification.

Lake Superior↗

USGS2005

Evolution of large body size in abalones (Haliotis): Patterns and implications

Kelps and other fleshy macroalgae - dominant reef-inhabiting organisms in cool - seasmay have radiated extensively following late Cenozoic polar cooling, thus triggering a chain of evolutionary change in the trophic ecology of nearshore temperate ecosystems. We explore this hypothesis through an analysis of body size in the abalones (Gastropoda; Haliotidae), a widely distributed group in modern oceans that displays a broad range of body sizes and contains fossil representatives from the late Cretaceous (60-75 Ma). Geographic analysis of maximum shell length in living abalones showed that small-bodied species, while most common in the Tropics, have a cosmopolitan distribution, whereas large-bodied species occur exclusively in cold-water ecosystems dominated by kelps and other macroalgae. The phylogeography of body size evolution in extant abalones was assessed by constructing a molecular phylogeny in a mix of large and small species obtained from different regions of the world. This analysis demonstrates that small body size is the plesiomorphic state and largeness has likely arisen at least twice. Finally, we compiled data on shell length from the fossil record to determine how (slowly or suddenly) and when large body size arose in the abalones. These data indicate that large body size appears suddenly at the Miocene/Pliocene boundary. Our findings support the view that fleshy-algal dominated ecosystems radiated rapidly in the coastal oceans with the onset of the most recent glacial age. We conclude with a discussion of the broader implications of this change. ?? 2005 The Paleontological Society. All rights reserved.

Paleobiology↗

USGS1999

The evolution of trophic transmission

Parasite increased trophic transmission (PITT) is one of the more fascinating tales of parasite evolution. The implications of this go beyond cocktail party anecdotes and science fiction plots as the phenomenon is pervasive and likely to be ecologically and evolutionarily important. Although the subject has already received substantial review, Kevin Lafferty here focuses on evolutionary aspects that have not been fully explored, specifically: (1) How strong should PITT be? (2) How might sexual selection and limb autotomy facilitate PITT? (3) How might infrapopulation regulation in final hosts be important in determining avoidance of infected prey? And (4) what happens when more than one species of parasite is in the same intermediate host?

Parasitology Today↗

USGS2008

Thermal and energetic constraints on ectotherm abundance: A global test using lizards

Population densities of birds and mammals have been shown to decrease with body mass at approximately the same rate as metabolic rates increase, indicating that energetic needs constrain endotherm population densities. In ectotherms, the exponential increase of metabolic rate with body temperature suggests that environmental temperature may additionally constrain population densities. Here we test simple bioenergetic models for an ecologically important group of ectothermic vertebrates by examining 483 lizard populations. We find that lizard population densities decrease as a power law of body mass with a slope approximately inverse to the slope of the relationship between metabolic rates and body mass. Energy availability should limit population densities. As predicted, environmental productivity has a positive effect on lizard density, strengthening the relationship between lizard density and body mass. In contrast, the effect of environmental temperature is at most weak due to behavioral thermoregulation, thermal evolution, or the temperature dependence of ectotherm performance. Our results provide initial insights into how energy needs and availability differentially constrain ectotherm and endotherm density across broad spatial scales. ?? 2008 by the Ecological Society of America.

Ecology↗

USGS2008

North American Bird Banding and quantitative population ecology

Early bird-banding programs in North America were developed to provide descriptions of bird migration and movement patterns. This initial interest in description quickly evolved into more quantitative interests in two ways. There was (1) interest in quantifying migration and movement patterns, and (2) rapid recognition that re-observations of marked birds provided information about other parameters relevant to population dynamics. These included survival rate, recruitment rate, and population size. The evolution of methods for estimating population size, survival, recruitment, and movement is reviewed and we show it to be closely tied to bird-banding data. These estimation methods have been used with bird-banding data to draw important inferences about evolutionary ecology, population ecology, and population management. Illustrative examples of such inferences are provided.

Book chapter↗

USGS2025

The role of ecology in allopatric speciation of darters in the Central Highlands, USA

Allopatric speciation is the predominant mode of speciation in riverine fishes. However, the relative importance of genetic drift versus natural selection in the allopatric speciation of these fishes remain uncertain. Here, we present a case study that demonstrates the role of ecology in the diversification of a group of imperiled freshwater fishes from the central United States. We integrate a phylogenomic dataset with analyses of streamwise distance, environmental variables, meristic and morphological traits, and diet to investigate the ecological context and outcomes of allopatric speciation within a species complex comprising the Slenderhead Darter Percina phoxocephala (Nelson), Ouachita Darter Percina brucethompsoni (Robison, Cashner, and Near), and Longnose Darter Percina nasuta (Bailey). We find that two of the species traditionally delimited based on disparity in snout length, P. phoxocephala and P. nasuta , are polyphyletic, revealing three instances of the parallel evolution of snout length disparity. We propose a revised taxonomy including the delimitation of six new species based on disparity in phenotypic traits and phylogenomic analyses. We find that morphological differences are not correlated with genetic divergence but are congruent with variations in diet and environmental niches, suggesting a role for ecological factors in allopatric speciation of riverine fishes.

Arkansas, Kansas, Missouri, Oklahoma↗

USGS1999

Data set incongruence and correlated character evolution: An example of functional convergence in the hind-limbs of stifftail diving ducks

The unwitting inclusion of convergent characters in phylogenetic estimates poses a serious problem for efforts to recover phylogeny. Convergence is not inscrutable, however, particularly when one group of characters tracks phylogeny and another set tracks adaptive history. In such cases, convergent characters may be correlated with one or a few functional anatomical units and readily identifiable by using comparative methods. Stifftail ducks (Oxyurinae) offer one such opportunity to study correlated character evolution and function in the context of phylogenetic reconstruction. Morphological analyses place stifftail ducks as part of a large clade of diving ducks that includes the sea ducks (Mergini), Hymenolaimus, Merganetta , and Tachyeres , and possibly the pochards (Aythyini). Molecular analyses, on the other hand, place stifftails far from other diving ducks and suggest, moreover, that stifftails are polyphyletic. Mitochondrial cytochrome b gene sequences of eight stifftail species traditionally supposed to form a clade were compared with each other and with sequences from 50 other anseriform and galliform species. Stifftail ducks are not the sister group of sea ducks but lie outside the typical ducks (Anatinae). Of the four traditional stifftail genera, monophyly of Oxyura and its sister group relationship with Nomonyx are strongly supported. Heteronetta probably is the sister group of that clade, but support is weak. Biziura is not a true stifftail. Within Oxyura , Old World species ( O. australis, O. leucocephala, O. maccoa ) appear to form a clade, with New World species ( O. jamaicensis, O. vittata ) branching basally. Incongruence between molecules and morphology is interpreted to be the result of adaptive specialization and functional convergence in the hind limbs of Biziura and true stifftails. When morphological characters are divided into classes, only hind-limb characters are significantly in conflict with the molecular tree. Likewise, null models of synonymous and nonsynonymous substitution based on patterns of codon-degeneracy and chemical dissimilarity indicate that the nucleotide and amino acid changes postulated by the molecular tree are more plausible than those postulated by the morphological tree. These findings teach general lessons about the utility of highly adaptive characters (in particular those related to foraging ecology) and underscore the problems that convergence can pose for attempts to recover phylogeny. They also demonstrate how the concept of natural data partitions and simple models of evolution (e.g., parsimony, likelihood, neutrality) can be used to test the accuracy of independent phylogenetic estimates and provide arguments in favor of one tree topology over another.

Systematic Biology↗

USGS2008

Biomorphodynamics: Physical-biological feedbacks that shape landscapes

Plants and animals affect morphological evolution in many environments. The term "ecogeomorphology" describes studies that address such effects. In this opinion article we use the term "biomorphodynamics" to characterize a subset of ecogeomorphologic studies: those that investigate not only the effects of organisms on physical processes and morphology but also how the biological processes depend on morphology and physical forcing. The two-way coupling precipitates feedbacks, leading to interesting modes of behavior, much like the coupling between flow/sediment transport and morphology leads to rich morphodynamic behaviors. Select examples illustrate how even the basic aspects of some systems cannot be understood without considering biomorphodynamic coupling. Prominent examples include the dynamic interactions between vegetation and flow/sediment transport that can determine river channel patterns and the multifaceted biomorphodynamic feedbacks shaping tidal marshes and channel networks. These examples suggest that the effects of morphology and physical processes on biology tend to operate over the timescale of the evolution of the morphological pattern. Thus, in field studies, which represent a snapshot in the pattern evolution, these effects are often not as obvious as the effects of biology on physical processes. However, numerical modeling indicates that the influences on biology from physical processes can play a key role in shaping landscapes and that even local and temporary vegetation disturbances can steer large-scale, long-term landscape evolution. The prevalence of biomorphodynamic research is burgeoning in recent years, driven by societal need and a confluence of complex systems-inspired modeling approaches in ecology and geomorphology. To make fundamental progress in understanding the dynamics of many landscapes, our community needs to increasingly learn to look for two-way, biomorphodynamic feedbacks and to collect new types of data to support the modeling of such emergent interactions. Copyright 2008 by the American Geophysical Union.

Water Resources Research↗

USGS2022

Undeveloped and developed phases in the centennial evolution of a barrier-marsh-lagoon system: The case of Long Beach Island, New Jersey

Barrier islands and their associated backbarrier environments protect mainland population centers and infrastructure from storm impacts, support biodiversity, and provide long-term carbon storage, among other ecosystem services. Despite their socio-economic and ecological importance, the response of coupled barrier-marsh-lagoon environments to sea-level rise is poorly understood. Undeveloped barrier-marsh-lagoon systems typically respond to sea-level rise through the process of landward migration, driven by storm overwash and landward mainland marsh expansion. Such response, however, can be affected by human development and engineering activities such as lagoon dredging and shoreline stabilization. To better understand the difference in the response between developed and undeveloped barrier-marsh-lagoon environments to sea-level rise, we perform a local morphologic analysis that describes the evolution of Long Beach Island (LBI), New Jersey, over the last 182 years. We find that between 1840 and 1934 the LBI system experienced landward migration of all five boundaries, including 171 meters of shoreline retreat. Between the 1920s and 1950s, however, there was a significant shift in system behavior that coincided with the onset of groin construction, which was enhanced by beach nourishment and lagoon dredging practices. From 1934 to 2022 the LBI system experienced ~22 meters of shoreline progradation and a rapid decline in marsh platform extent. Additionally, we extend a morphodynamic model to describe the evolution of the system in terms of five geomorphic boundaries: the ocean shoreline and backbarrier-marsh interface, the seaward and landward lagoon-marsh boundaries, and the landward limit of the inland marsh. We couple this numerical modeling effort with the map analysis during the undeveloped phase of LBI evolution, between 1840 and 1934. Despite its simplicity, the modeling framework can describe the average cross-shore evolution of the barrier-marsh-lagoon system during this period without accounting for human landscape modifications, supporting the premise that natural processes were the key drivers of morphological change. Overall, these results suggest that anthropogenic effects have played a major role in the evolution of LBI over the past century by altering overwash fluxes and marsh-lagoon geometry; this is likely the case for other barrier-marsh-lagoon environments around the world.

New Jersey↗

USGS2026

A Lake Charr pangenome reveals highly conserved Ohnologs as drivers of phenotypic diversity

Whole-genome duplication (WGD) is hypothesized to spur evolutionary diversification by producing genome-wide duplicate gene sets (Ohnologs) that are initially functionally redundant but can diverge markedly as the effects of relaxed selection accumulate over time. However, the underlying mechanisms remain unclear, in part because genomic studies often reconstruct Ohnolog evolution over millions of years, during which subsequent mutations can obscure deep-time signals. Investigating the relationship between Ohnolog evolution and diversification on a contemporary timescale offers clearer insights. We explore this relationship in Lake Charr ( Salvelinus namaycush ), where ∼10% of genes are retained highly conserved polyploid duplicates following the Salmonid-Specific Fourth Round WGD. Using 31 chromosome-level assemblies of Lake Charr from morphologically and ecologically diverse populations, joined into a pangenome graph, we characterized 189,555 structural variants (SVs) that were significantly less likely to affect genes retained as sequence-conserved Ohnolog pairs, nuancing the hypothesis that gene redundancy, relaxed selection, and functional diversification are intertwined. However, we found that SVs affecting such conserved Ohnologs may be potent drivers of adaptive evolution. Notably, we identified a putative 938-Kb interchromosomal translocation containing 25 genes with highly conserved Ohnologs in a paralogous (but untranslocated) genomic block. This putative translocation appears to have facilitated Ohnolog divergence in ankrd11 and hp , genes putatively linked to craniofacial and lipid metabolic diversity in sympatric Lake Superior morphs. This research reveals that conserved Ohnologs previously presumed to be redundant remain a reservoir for adaptive change.

BioRxiv↗

USGS2017

International Watershed Technology: Improving Water Quality and Quantity at the Local, Basin, and Regional Scales

This article introduces the five papers in the “International Watershed Technology” collection. These papers were selected from 60 technical presentations at the fifth biennial ASABE 21st Century Watershed Technology Conference and Workshop: Improving the Quality of Water Resources at Local, Basin, and Regional Scales, held in Quito, Ecuador, on 3-9 December 2016. The conference focused on solving spatial and temporal water quality and quantity problems and addressed topics such as watershed management in developing countries, aquatic ecology and ecohydrology, ecosystem services, climate change mitigation strategies, flood forecasting, remote sensing, and water resource policy and management. While diverse, the presentation topics reflected the continuing evolution of the “data mining” and “big data” themes of past conferences related to geospatial data applications, with increasing emphasis on practical solutions. The papers selected for this collection represent applications of spatial data analyses toward practical ends with a theme of “tools and techniques for sustainability.” The papers address a range of topics, including the matching of crops with water availability, and assessing the environmental impacts of agricultural production. The papers identify some of the latest tools and techniques for improving sustainability in watershed resource management that are relevant to both developing and developed countries.

Transactions of the ASABE↗