Disjunct Regions Research Articles

Genetic diversity and population structure of an insect-pollinated and bird-dispersed dioecious tree Magnolia kwangsiensis in a fragmented karst forest landscape.

This study combined population genetics and parentage analysis to obtain foundational data for the conservation of Magnolia kwangsiensis. M. kwangsiensis is a Class I tree species that occurs in two disjunct regions in a biodiversity hotspot in southwest China. We assessed the genetic diversity and structure of this species across its distribution range to support its conservation management. Genetic diversity and population structure of 529 individuals sampled from 14 populations were investigated using seven nuclear simple sequence repeat (nSSR) markers and three chloroplast DNA (cpDNA) fragments. Parentage analysis was used to evaluate the pollen and seed dispersal distances. The nSSR marker analysis revealed a high genetic diversity in M. kwangsiensis, with an average observed (Ho) and expected heterozygosities (He) of 0.726 and 0.687, respectively. The mean and maximum pollen and seed dispersal distances were 66.4 and 95.7 m and 535.4 and 553.8 m, respectively. Our data revealed two distinct genetic groups, consistent with the disjunct geographical distribution of the M. kwangsiensis populations. Both pollen and seed dispersal movements help maintain genetic connectivity among M. kwangsiensis populations, contributing to high levels of genetic diversity. Both genetically differentiated groups corresponding to the two disjunct regions should be recognized as separate conservation units.

Cryptic divergences and repeated hybridizations within the endangered “living fossil” dove tree (Davidia involucrata) revealed by whole genome resequencing

The identification and understanding of cryptic intraspecific evolutionary units (lineages) are crucial for planning effective conservation strategies aimed at preserving genetic diversity in endangered species. However, the factors driving the evolution and maintenance of these intraspecific lineages in most endangered species remain poorly understood. In this study, we conducted resequencing of 77 individuals from 22 natural populations of Davidia involucrata, a “living fossil” dove tree endemic to central and southwest China. Our analysis revealed the presence of three distinct local lineages within this endangered species, which emerged approximately 3.09 and 0.32 million years ago. These divergence events align well with the geographic and climatic oscillations that occurred across the distributional range. Additionally, we observed frequent hybridization events between the three lineages, resulting in the formation of hybrid populations in their adjacent as well as disjunct regions. These hybridizations likely arose from climate-driven population expansion and/or long-distance gene flow. Furthermore, we identified numerous environment-correlated gene variants across the total and many other genes that exhibited signals of positive evolution during the maintenance of two major local lineages. Our findings shed light on the highly dynamic evolution underlying the remarkably similar phenotype of this endangered species. Importantly, these results not only provide guidance for the development of conservation plans but also enhance our understanding of evolutionary past for this and other endangered species with similar histories.

A parcellation scheme of mouse isocortex based on reversals in connectivity gradients.

The brain is composed of several anatomically clearly separated structures. This parcellation is often extended into the isocortex, based on anatomical, physiological, or functional differences. Here, we derive a parcellation scheme based purely on the spatial structure of long-range synaptic connections within the cortex. To that end, we analyzed a publicly available dataset of average mouse brain connectivity, and split the isocortex into disjunct regions. Instead of clustering connectivity based on modularity, our scheme is inspired by methods that split sensory cortices into subregions where gradients of neuronal response properties, such as the location of the receptive field, reverse. We calculated comparable gradients from voxelized brain connectivity data and automatically detected reversals in them. This approach better respects the known presence of functional gradients within brain regions than clustering-based approaches. Placing borders at the reversals resulted in a parcellation into 41 subregions that differs significantly from an established scheme in nonrandom ways, but is comparable in terms of the modularity of connectivity between regions. It reveals unexpected trends of connectivity, such as a tripartite split of somatomotor regions along an anterior to posterior gradient. The method can be readily adapted to other organisms and data sources, such as human functional connectivity.

Cenozoic migration of a desert plant lineage across the North Atlantic.

Previous paleobotanical work concluded that Paleogene elements of the sclerophyllous subhumid vegetation of western Eurasia and western North America were endemic to these disjunct regions, suggesting that the southern areas of the Holarctic flora were isolated at that time. Consequently, molecular studies invoked either parallel adaptation to dry climates from related ancestors, or long-distance dispersal in explaining disjunctions between the two regions, dismissing the contemporaneous migration of dry-adapted lineages via land bridges as unlikely. We report Vauquelinia (Rosaceae), currently endemic to western North America, in Cenozoic strata of western Eurasia. Revision of North American fossils previously assigned to Vauquelinia confirmed a single fossil-species of Vauquelinia and one of its close relative Kageneckia. We established taxonomic relationships of fossil-taxa using diagnostic character combinations shared with modern species and constructed a time-calibrated phylogeny. The fossil record suggests that Vauquelinia, currently endemic to arid and subdesert environments, originated under seasonally arid climates in the Eocene of western North America and subsequently crossed the Paleogene North Atlantic land bridge (NALB) to Europe. This pattern is replicated by other sclerophyllous, dry-adapted and warmth-loving plants, suggesting that several of these taxa potentially crossed the North Atlantic via the NALB during Eocene times.

Fouling of a boat hull by the invasive zooxanthellate coral Oculina patagonica - could shipping be enhancing its unique large-scale spread?

The zooxanthellate coral Oculina patagonica (Scleractinia, Oculinidae) is an invasive species that was first recorded in the Mediterranean Sea in 1966 and currently has expanded its distribution across both the western and eastern Atlantic. Here, we reviewed data from multiple databases to compile historical distribution records of O. patagonica and analyze its spread. The chronological review highlights the unique spread of this zooxanthellate coral during the last two decades, expanding its distribution in multiple directions and establishing populations in disjunct regions separated by ~12,000 km, including most biogeographic regions within the temperate Mediterranean, the subtropical eastern Atlantic and the tropical Gulf of Mexico. The biogeographic distribution discontinuities documented in O. patagonica are difficult to explain by larval dispersion alone; therefore, other mechanisms may contribute to its large-scale spread pattern. This study provides the first observation of several O. patagonica colonies fouling the hull and metal crevices of a recreational boat in the western Mediterranean (37°N, 1°W). The presence of several mature O. patagonica colonies on a single ship, rather than a single coral colony rafting on natural or artificial floating substrates, could greatly increase its potential for spread, coupled with its ecological and biological traits adapted to rafting. We hypothesized that the travel of coral populations by shipping may act as a dispersal vector contributing to explaining the long-distance dispersal events and secondary introductions experienced by this invasive species. The broad spread of O. patagonica, which is able to drive phase shifts from macroalgae dominance to coral dominance, is consistent with the ongoing process of coral-mediated tropicalization of high-latitude shallow rocky reefs under current global change

The logarithmic phase singularity in the inverted harmonic oscillator

A spacetime singularity is located at the center of a black hole and surrounded by an event horizon, separating spacetime into two disjunct regions: one of them accessible to an outside observer and one that is not. At the event horizon, a logarithmic phase singularity emerges in the mode functions of a massless scalar field, being characteristic for Hawking radiation emitted by the black hole. We demonstrate that related features are present in the elementary quantum system of an inverted harmonic oscillator. Central to our analysis are the energy eigenfunctions of this system and their phase space representation. At first glance, neither a horizon nor a logarithmic phase dependence are apparent. However, both features are hidden in phase space and revealed by a suitable coordinate transformation. In particular, we show that the Fourier transform of a logarithmic phase leads to an expression that is reminiscent of a specific quantum statistics, governing the reflection and transmission coefficients of the inverted harmonic oscillator.

Phenotypic differentiation among native, expansive and introduced populations influences invasion success

AbstractAimHumans influence species distributions by modifying the environment and by dispersing species beyond their natural ranges. Populations of species that have established in disjunct regions of the world may exhibit trait differentiation from native populations due to founder effects and adaptations to selection pressures in each distributional region. We compared multiple native, expansive and introduced populations of a single species across the world, considering the influence of environmental stressors and transgenerational effects.LocationUnited States Gulf and Atlantic coasts, United States interior, European Atlantic and Mediterranean coasts, east coast of Australia.TaxonBaccharis halimifolia L. (eastern baccharis).MethodsWe monitored seed germination, seedling emergence, survival and early growth in a common garden experiment, conducted with over 18,200 seeds from 80 populations. We also evaluated the influence of environmental stress and maternal traits on progeny performance.ResultsIntroduced European Atlantic populations had faster germination and early growth than native populations. However, this was not the case for the more recently naturalized European Mediterranean populations. Introduced Australian populations grew faster than native populations in non‐saline environments but had lower survival in saline conditions commonly encountered in the native range. Similarly, expansive inland US populations germinated faster than coastal native populations in non‐saline environments but grew and germinated more slowly in saline environments. Maternal inflorescence and plant size were positively related with seed germination and seedling survival, whereas flower abundance was positively correlated with seedling early growth and survival. However, maternal traits explained a much lower fraction of the total variation in early demographic stages of B. halimifolia than did distributional range.Main conclusionsPhenotypic differentiation could allow B. halimifolia to adapt to different biotic and abiotic selection pressures found in each distributional range, potentially contributing to its success in introduced and expansive ranges.

Signatures of north-eastern expansion and multiple refugia: genomic phylogeography of the Pine Barrens tree frog,Hyla andersonii(Anura: Hylidae)

AbstractRange fragmentation poses challenges for species persistence over time and can be caused by both historical and contemporary processes. We combined genomic data, phylogeographical model testing and palaeoclimatic niche modelling to infer the evolutionary history of the Pine Barrens tree frog (Hyla andersonii), a seepage bog specialist, in eastern North America to gain a better understanding of the historical context of its fragmented distribution. We sampled H. andersonii populations across the three disjunct regions of the species range: Alabama/Florida (AF), the Carolinas (CL) and New Jersey (NJ). Phylogenetic relationships within H. andersonii were consistent between the nuclear species tree and mitochondrial analyses, indicating divergence between AF and CL/NJ (Atlantic clade) ~0.9 Mya and divergence of the NJ clade ~0.15 Mya. Several predictions of north-eastern expansion along the Atlantic coast were supported by phylogeographical analyses. Model testing using genome-wide single nucleotide polymorphism data and species distribution models both provided evidence for multiple disjunct refugia. This comprehensive phylogeographical study of H. andersonii demonstrates a long history of range fragmentation within an endemic coastal plain species and highlights the influence of historical climate change on the current distribution of species and their genetic diversity.

Refugia during the last glacial period and the origin of the disjunct distribution of an insular plant

AbstractAimAlthough many phylogeographic studies have focused on continental refugia, the roles of islands as refugia have long been overlooked. In this study, we conducted phylogeographic studies of a plant with insular distribution, Microtropis japonica, to elucidate the potential roles of islands as refugia during recent glacial periods. Specifically, we test the hypothesis that two remote groups of Japanese islands (the Izu and Ryukyu Islands) were refugia for M japonica.LocationThe Izu and Ryukyu Islands of Japan and their adjacent areas including the Japanese mainland and Taiwan.TaxonMicrotropis japonica (Celastraceae).MethodsA total of 363 individuals were sampled from 44 populations of M japonica. To elucidate population genetic differentiation and demographic change in M japonica, we performed molecular variance and mismatch distribution analyses based on chloroplast DNA (cpDNA) sequence variations and Bayesian clustering and gene flow estimates based on nuclear single‐nucleotide polymorphism (SNP) data. In addition, to examine distribution changes, ecological niche modelling using the maximum entropy method was used to determine suitable habitats existing currently or during the last glacial maximum, using occurrence data and six bioclimatic variables.ResultsBoth cpDNA and nuclear SNP data showed genetic differentiation between two disjunct regions. However, cpDNA data indicated genetic differentiation within the Ryukyu Islands but not within the Izu Islands, while nuclear SNP data indicated genetic differentiation within both island groups. Ecological niche modelling showed that both the Izu and Ryukyu archipelagos had contained some islands with a climate compatible with modern M japonica climate envelopes despite climate oscillations.Main conclusionsIslands within both the Izu and Ryukyu archipelagos may have supported M japonica populations throughout historical climate oscillations. The current disjunct distribution of M japonica strongly reflects its refugial locations during the last glacial period and the subsequent range expansion. Islands were important refuges, contributing to the modern disjunct distribution of M japonica.

Genetic Patterns and Climate Modelling Reveal Challenges for Conserving Sclerolaena napiformis (Amaranthaceae s.l.) an Endemic Chenopod of Southeast Australia

Sclerolaena napiformis is a perennial chenopod endemic to southeast Australia. Human-mediated habitat loss and fragmentation over the past century has caused a rapid decline in abundance and exacerbated reduced connectivity between remnant populations across three disjunct regions. To assess conservation requirements, we measured the genetic structure of 27 populations using double digest RADseq). We combined our genetic data with habitat models under projected climate scenarios to identify changes in future habitat suitability. There was evidence of regional differentiation that may pre-date (but also may be compounded) by recent habitat fragmentation. We also found significant correlation between genetic and geographic distance when comparing sites across regions. Overall, S. napiformis showed low genetic diversity and a relatively high proportion of inbreeding/selfing. Climate modelling, based on current occupancy, predicts a reduction in suitable habitat for S. napiformis under the most conservative climate change scenario. We suggest that the best conservation approach is to maximise genetic variation across the entire species range to allow dynamic evolutionary processes to proceed. We recommend a conservation strategy that encourages mixing of germplasm within regions and permits mixed provenancing across regions to maximise genetic novelty. This will facilitate shifts in genetic composition driven by individual plant fitness in response to the novel environmental conditions this species will experience over the next 50 years.

A review of transition zones in biogeographical classification

AbstractTransition zones are problematic in biogeographical classification as they represent artificial biotic areas. A review of transition zones into existing biogeographical classifications shows conflicting area taxonomies. While many authors consider transition zones as overlap zones or areas of biotic mixing, only a few have considered excluding them from biogeographical classification all together. One way of incorporating transition zones into a natural classification is by treating them as artefacts of geographically overlapping temporally disjunct biotic areas. In doing so, geographically overlapping biotic areas may occupy the same space but have different boundaries and histories. Temporally disjunct areas do form natural hierarchical classifications, as seen in the paleobiogeographical literature. A revision of each transition zone will determine whether they are artificial areas, areas within their own right or potentially geographically overlapping temporally disjunct regions.

New Population of the Rare Dragonfly Ophiogomphus howei (Odonata: Gomphidae) in Southern Michigan, United States.

Ophiogomphus howei Bromley is a rare North American dragonfly, given a global conservation rank of Vulnerable by NatureServe. This species inhabits localized stretches of a limited number of typically undisturbed, high-quality, forested rivers in two disjunct regions in North America. We describe a new population in between the known ranges from an impaired river in a largely urban watershed in southern Michigan, United States. We also report a previously overlooked specimen from a new location in Pennsylvania, United States, and provide current occurrence and conservation status of the species in North America.

<p class="HeadingRunIn"><strong>An ongoing saga: Endemic branchiobdellidans (Annelida: Clitellata) on translocated commercial North American crayfish</strong></p>

Over the last 130 years demand for crayfish has exceeded regional supplies around the world, so stocks, primarily from North America, have been imported to satisfy this need. These demands are human based and include gastronomy, sport fishing bait, food for rearing animals, educational aides, ornamentation in waterbodies, and more recently a significant increase in pet crayfish sales. The three most common commercial species from North America are Pacifastacus leniusculus, Procambarus clarkii and Orconectes limosus, although four other species are increasing in importance as they become more widely distributed. All of these crayfish in their endemic range have been reported to carry branchiobdellidan annelids. Therefore, when the crayfish are translocated, their ectosymbionts likely accompany them. Eighty-six potentially transportable branchiobdellidans are recognized in this paper, along with the distribution of six species known to have been translocated. Moreover, branchiobdellidans endemic to the translocation regions have adopted introduced crustacean hosts, which demonstrates that branchiobdellidan host species specificity is not as restrictive as many researchers believe. On the evidence to date, these translocated branchiobdellidans appear to have the same relationship and cause the same amount of damage, if any, as those on their endemic crayfish hosts. The geographical distribution of endemic branchiobdellidan—crayfish species associations are unique to each of four disjunct regions as defined by Bănărescu: Euro-Mediterranean, East Asian, western North American and eastern North American; the latter includes eastward drainages from Canada to Costa Rica.

Uso de hospedadores por el muérdago Argentino Ligaria cuneifolia (Loranthaceae) a lo largo de su distribución geográfica

Introducción y objetivos: Ligaria cuneifolia (Loranthaceae) posee una amplia distribución desde Perú al centro de Argentina y Uruguay. Esta especie habita en tres regiones geográficas en forma disyunta a lo largo de cordillera de los Andes, las Sierras Centrales de Argentina y en el este de Sudamérica, en Uruguay y sur de Brasil. El objetivo de este trabajo fue determinar el rango de hospedadores de Ligaria cuneifolia en toda su distribución geográfica y analizar el uso de hospedadores en cada una de las regiones geográficas (Andes, Centro y Este). M&M: Se registró el uso de hospedadores de Ligaria cuneifolia y distribución geográfica en base a ejemplares depositados en herbarios. Resultados: En total se registraron 35 especies de hospedadores nativos, comprendidas en 22 géneros y 12 familias. Además se registaron 11 especies no nativas en todas las areas. Los géneros de hospedadores con mayor número de registros fueron Schinus, Prosopis, Geoffroea, Larrea y Vachellia. Conclusiones: El uso de hospedadores no estuvo directamente asociado a las áreas geográficas. La región Andes fue la que presentó una mayor diversidad de especies, géneros y familias de hospedadores.

Population genetic structure of the whorl-leaf watermilfoil Myriophyllum verticillatum shaped by topography and geographic distance

Interpopulation gene flow plays an important role in determining population genetic structure. In this study, we sampled 24 populations of the whorl-leaf watermilfoil Myriophyllum verticillatum from three disjunct regions in China (Northwest China, Northeast China, and the Qinghai-Tibet Plateau (QTP) plus Southwest China) with different topographies and examined its population genetic structure using 17 microsatellite loci. Deserts, plains, and mountains are the main geomorphological features of Northwest China, Northeast China, and the QTP plus Southwest China, respectively. High genetic differentiation and genetic isolation by geographic distance were observed at the overall scale and in all three regions. When compared among the three regions, the lowest level of genetic differentiation and weakest correlation between genetic and geographic distances were presented in Northeast China. Two genetic clusters corresponding to Northwest China and the other two regions were identified, suggesting unequal gene flow among the three disjunct regions. Our findings emphasize the role of topography and geographic distance in shaping population genetic structure in aquatic plants.

Holantarctic diversity varies widely among genetic loci within the gametophytically allotriploid peat moss Sphagnum × falcatulum.

The traditional approach used in analyses of population genetic data for historical inference is to average across multiple marker loci, but averaging conflates the different evolutionary signals provided by stable vs. labile markers. We used a battery of microsatellites with a wide range of mutation/substitution rates, grouping them into two sets (stable and hypervariable) to provide a more nuanced reconstruction of the population genetics and evolutionary history of the allotriploid peat moss Sphagnum × falcatulum across three disjunct regions. Shannon diversity translation analyses show that the relative apportionment of total within-species allelic diversity (∆WS ) within and among strata ranges widely, both between the two sets and within and among regions. The majority of diversity in the stable set was inherited directly from the ancestors of this genetically complex allopolyploid, but most of the diversity in the hypervariable set has developed post-hybrid-origin. It is useful to group markers into sets having similar evolutionary lability, with each set being analyzed separately, particularly for allopolyploids. A methodology for determining how to group markers into such sets is presented, which can be applied to the requirements of other studies. Within-individual allelic diversity (ΔWI ) should be addressed in genetic studies on allopolyploids. Allotriploid haplotypes based on a set of nine highly stable microsatellites appear to serve as a clonal-detection set for S. × falcatulum. An additive "allele-metric" diversity approach is introduced, which facilitates a direct comparison of within- and among-stratum diversity components at all levels of diversity.

Genetic and morphometric divergence in the Garnet-Throated Hummingbird Lamprolaima rhami (Aves: Trochilidae).

Cloud forests are one of the most endangered ecosystems in the Americas, as well as one of the richest in biological diversity in the world. The species inhabiting these forests are susceptible to environmental changes and characterized by high levels of geographic structure. The Garnet-Throated Hummingbird, Lamprolaima rhami, mainly inhabits cloud forests, but can also be found in other habitats. This species has a highly restricted distribution in Mesoamerica, and five disjunct regions have been delimited within the current geographic distribution of the species from Mexico to Honduras. According to variation in size and color, three subspecies have been described: L. r. rhami restricted to the Mexican highlands and Guatemala, L. r. occidentalis distributed in Guerrero (Mexico), and L. r. saturatior, distributed in the highlands from Honduras and El Salvador. We analyzed the levels of geographic structure in L. rhami and its taxonomic implications. We used mitochondrial and nuclear DNA to analyze genetic variation, demographic history, divergence times, reconstructed a multilocus phylogeny, and performed a species delimitation analyses. We also evaluated morphological variation in 208 specimens. We found high levels of genetic differentiation in three groups, and significant variation in morphological traits corresponding with the disjunct geographic populations. L. rhami presents population stability with the highest genetic variation explained by differences between populations. Divergence time estimates suggest that L. rhami split from its sister group around 10.55 million years ago, and the diversification of the complex was dated ca. 0.207 Mya. The hypotheses tested in the species delimitation analyses validated three independent lineages corresponding to three disjunct populations. This study provides evidence of genetic and/or morphometric differentiation between populations in the L. rhami complex where four separate evolutionary lineages are supported: (1) populations from the Sierra Madre Oriental and the highlands of Oaxaca (rhami), (2) populations from the highlands of Guerrero (occidentalis), (3) populations from the highlands of Chiapas and Guatemala (this is a non-previously proposed potential taxon: tacanensis), and (4) populations from the highlands of Honduras and El Salvador (saturatior). The main promoters of the geographic structure found in the L. rhami complex are likely the Isthmus of Tehuantepec as a geographic barrier, isolation by distance resulting from habitat fragmentation, and climatic conditions during the Pleistocene.

Systematics and biogeography of sciophilous cyanobacteria; an ecological and molecular description of Albertania skiophila (Leptolyngbyaceae) gen. & sp. nov.

:Filamentous cyanobacteria grow as phototrophic biofilms in Maltese hypogea. Within these sheltered habitats, the prevailing relative humidity is high throughout the year, water seeps through the porous calcareous substrata and the irradiance is minimal. Isolated sciophilous cyanobacterial strains, adapted to tolerate and thrive in such environments, were studied using cytomorphological, ecological and genetic approaches. Light and electron microscopy revealed simple green trichomes 2–3 μm wide, made up of cells with parietal thylakoids, a rounded apical tip and surrounded by multistratified colourless sheaths. Phylogenetic analysis based on the 16S ribosomal RNA gene resulted in a new cluster of sequences that indicated a separate position at the generic level and justified the creation of the new genus Albertania. The strains were closely related (98% similarity or higher) and distantly related to other established cyanobacterial taxa (< 95%). The 16–23S internal transcribed spacer secondary folding structures were also unique. The clade consisted of six sequences isolated from phototrophic biofilms growing in five hypogea in Malta and Italy that are geographically isolated. The strains are described as Albertania skiophila gen. & sp. nov. since they form a monophyletic cluster made up of strains having a similar cytomorphology, ecology and molecular biology from two disjunct regions in Europe. Albertania skiophila strains are endemic to a specific habitat and distinct geographical region, leading to a defined biogeographical distribution in hypogea and caves around the Mediterranean region.

Adiabatic cooling processes in frustrated magnetic systems with pyrochlore structure.

We investigate in detail the process of adiabatic cooling in the framework of the exactly solvable antiferromagnetic spin-1/2 Ising model in the presence of the external magnetic field on an approximate lattice with pyrochlore structure. The behavior of the entropy of the model is studied and exact values of the residual entropies of all ground states are found. The temperature variation of the system under adiabatic (de)magnetization is investigated and the central role of the macroscopically degenerated ground states in cooling processes is explicitly demonstrated. It is shown that the model parameter space of the studied geometrically frustrated system is divided into five disjunct regions with qualitatively different processes of the adiabatic cooling. The effectiveness of the adiabatic (de)magnetization cooling in the studied model is compared to the corresponding processes in paramagnetic salts. It is shown that the processes of the adiabatic cooling in the antiferromagnetic frustrated systems are much more effective especially in nonzero external magnetic fields. It means that the frustrated magnetic materials with pyrochlore structure can be considered as very promising refrigerants mainly in the situations with nonzero final values of the magnetic field.

Assessing the scope for genetic rescue of an endangered butterfly: the case of the Eltham copper

Abstract Genetic rescue is an under‐utilised conservation strategy used to boost the genetic diversity and/or fitness of small, isolated populations through the introduction of novel genes. Effective implementation of genetic rescue requires an understanding of the evolutionary history and genetic distinctiveness of populations. The Eltham copper butterfly (ECB) is an endangered subspecies that exists as small, isolated populations across four disjunct regions in Victoria, Australia. Mitochondrial and nuclear sequence data were used to assess the genetic distinctiveness of ECB from its nearest relative: the fiery dull copper butterfly (FDC), explore the evolutionary history and population structure of ECB across its contemporary distribution, and assess the scope for genetic rescue of the most‐threatened ECB population in Eltham‐Greensborough. Findings support the current status of ECB and FDC as distinct evolutionary units, which should continue to be managed separately given current knowledge. Modest population genetic structure across the range of ECB was detected. However, low levels of historical gene flow and shared haplotypes between Eltham‐Greensborough and the northern regions suggest relatively recent divergence. Given relatively recent divergence, low population numbers and low genetic diversity, the population located in the Eltham‐Greensborough region is a strong candidate for genetic rescue. Using established criteria, explicit recommendations are made for the implementation of genetic rescue via translocations. Genetic rescue, together with ongoing habitat management, should improve genetic diversity, fitness and persistence of the ECB in the region most threatened by urban disturbance. Any risks associated with genetic rescue in conservation should be weighed against extinction risk as a result of inaction.