Rayna Camille Bell

Rayna Camille Bell
California Academy of Sciences · Department of Herpetology

Ph.D., Ecology & Evolutionary Biology, Cornell University

About

81
Publications
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1,754
Citations
Additional affiliations
August 2008 - August 2014
Cornell University
Position
  • PhD Student

Publications

Publications (81)
Article
Local adaptation to environmental heterogeneity across a landscape can result in population divergence and formation of lineages. On Guadeloupe Island, the active volcano, La Grande Soufrière, peaks at 1460 m a.s.l., with rainforest at low elevations transitioning to humid savannahs at high elevations. Two endemic sister species of Eleutherodactylu...
Article
Reed frogs (Hyperolius spp.) are the most species-rich genus in the family Hyperoliidae, a group of frogs endemic to sub-Saharan Africa and the Gulf of Guinea islands. Three species are endemic to oceanic islands in the archipelago, but the diversity and distribution of reed frogs on Bioko – a land-bridge island in the archipelago – remains unclear...
Article
Full-text available
Non-visual opsins are transmembrane proteins expressed in the eyes and other tissues of many animals. When paired with a light-sensitive chromophore, non-visual opsins form photopigments involved in various non-visual, light-detection functions including circadian rhythm regulation, light-seeking behaviors, and seasonal responses. Here we investiga...
Article
Species distributed across heterogeneous environments may undergo local adaptation, which can be limited by the homogenizing effects of gene flow. Lesser Antillean anoles exhibit dorsal colour variation associated with dramatic shifts in environment across small spatial scales, providing an excellent system for studying the maintenance of local ada...
Article
Full-text available
Visual systems adapt to different light environments through several avenues including optical changes to the eye and neurological changes in how light signals are processed and interpreted. Spectral sensitivity can evolve via changes to visual pigments housed in the retinal photoreceptors through gene duplication and loss, differential and coexpre...
Article
Full-text available
Natural history museums are vital repositories of specimens, samples and data that inform about the natural world; this Formal Comment revisits a Perspective that advocated for the adoption of compassionate collection practices, querying whether it will ever be possible to completely do away with whole animal specimen collection.
Article
The effects of host ecology and environmental conditions on infection dynamics of the amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) have been documented in several tropical and montane regions across the globe. These interactions are often complex and unique at local scales. Data on the historical and current chytridiomycosis-amphibi...
Article
Species whose ranges encompass substantial environmental variation should experience heterogeneous selection, potentially resulting in local adaptation. Repeated covariation between phenotype and environment across ecologically similar species inhabiting similar environments provides strong evidence for adaptation. Lesser Antillean anoles present a...
Preprint
Full-text available
Non-visual opsins are transmembrane proteins expressed in the eyes, skin, and brain of many animals. When paired with a light-sensitive chromophore, non-visual opsins form photopigment systems involved in various non-visual, light-detection functions, including circadian rhythm regulation, light-seeking behavior, and detection of seasonality. Previ...
Book
Full-text available
This open access book presents a comprehensive synthesis of the biodiversity of the oceanic islands of the Gulf of Guinea, a biodiversity hotspot off the west coast of Central Africa. Written by experts, the book compiles data from a plethora of sources – archives, museums, bibliography, official reports and previously unpublished data – to provide...
Chapter
Full-text available
The Gulf of Guinea, in the Atlantic coast of Central Africa, has three oceanic islands that arose as part of the Cameroon Volcanic Line. From northeast to southwest these are Príncipe (139 km ² ), São Tomé (857 km ² ), and Annobón (17 km ² ). Although relatively close to the adjacent mainland, the islands have distinct climactic and geomorphologic...
Chapter
Full-text available
The Gulf of Guinea oceanic islands (Príncipe, São Tomé, and Annobón) are among the most endemic-rich regions of the planet. Historical scientific studies of the islands’ unique biodiversity are scattered in a variety of publications, many of which are difficult to access. More recently, there has been a growing interest in the islands, which is ref...
Chapter
Full-text available
The oceanic islands of the Gulf of Guinea hold extraordinary levels of endemism across many taxonomic groups. Biodiversity surveys are still uncovering species new to science, and much work remains to be done on the evolution, ecology, and conservation of this unique biological heritage. The next 10 years will be crucial to find and implement devel...
Chapter
Full-text available
This chapter reviews current knowledge on the diversity of terrestrial reptiles in the Gulf of Guinea oceanic islands and provides a brief history of research on this group of animals. A total of 29 species of terrestrial reptiles (representing 14 genera and seven families) are resident on the Gulf of Guinea oceanic islands, of which 22 species are...
Chapter
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This chapter reviews the diversity, evolutionary relationships, ecology, and conservation of the Gulf of Guinea oceanic islands’ endemic caecilian and anuran fauna. A total of nine amphibian species (representing five families) are known from São Tomé and Príncipe islands, all of which are endemic. No amphibians have been reported from Annobón. Tax...
Chapter
Full-text available
As with most archipelagos, geography played a central role in the assembly and evolution of the endemic-rich biological communities of the Gulf of Guinea oceanic islands. The islands are located at moderate distances from the species-rich African continent that surrounds them to the east and north. This proximity facilitated colonization by many br...
Article
Full-text available
Pupil constriction has important functional consequences for animal vision, yet the evolutionary mechanisms underlying diverse pupil sizes and shapes are poorly understood. We aimed to quantify the diversity and evolution of pupil shapes among amphibians and to test for potential correlations to ecology based on functional hypotheses. Using photogr...
Article
Full-text available
Cryptogenic species are those whose native and introduced ranges are unknown. The extent and long history of human migration rendered numerous species cryptogenic. Incomplete knowledge regarding the origin and native habitat of a species poses problems for conservation management and may confound ecological and evolutionary studies. The Lesser Anti...
Article
Full-text available
Due to their limited geographic distributions and specialized ecologies, cave species are often highly endemic and can be especially vulnerable to habitat degradation within and surrounding the cave systems they inhabit. We investigated the evolutionary history of the West Virginia Spring Salamander (Gyrinophilus subterraneus), estimated the popula...
Article
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Background Differences in morphology, ecology, and behavior through ontogeny can result in opposing selective pressures at different life stages. Most animals, however, transition through two or more distinct phenotypic phases, which is hypothesized to allow each life stage to adapt more freely to its ecological niche. How this applies to sensory s...
Article
Full-text available
Some crepuscular and nocturnal animals are brightly marked yet the adaptive significance of their colorful patterns in low light, as found at twilight and night, is poorly understood. This phenomenon is particular prevalent in amphibians. Of the nearly 80% of nocturnal frogs, many exhibit color patterns with red, yellow, green and blue hues and/or...
Article
Full-text available
Color and pattern are often dynamic traits that change throughout an individual's lifetime. Still, long‐term shifts in coloration have received limited attention. Dendrobatid poison frogs are a classical system in the study of color and pattern evolution in which both sexual selection and predation avoidance are thought to drive the evolution of co...
Article
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The spectral characteristics of vertebrate ocular lenses affect the image of the world that is projected onto the retina, and thus help shape diverse visual capabilities. Here, we tested whether amphibian lens transmission is driven by adaptation to diurnal activity (bright light) and/or scansorial habits (complex visual environments). Spectral tra...
Article
The ability to bear live offspring, viviparity, has evolved multiple times across the tree of life and is a remarkable adaptation with profound life-history and ecological implications. Within amphibians the ancestral reproductive mode is oviparity followed by a larval life stage, but viviparity has evolved independently in all three amphibian orde...
Article
Secondary sympatry among sister lineages is strongly associated with genetic and ecological divergence. This pattern suggests that for closely related species to coexist in secondary sympatry, they must accumulate differences in traits that mediate ecological and/or reproductive isolation. Here, we characterized inter‐ and intra‐specific divergence...
Preprint
Full-text available
Pupil constriction has important functional consequences for animal vision, yet the evolutionary mechanisms underlying diverse pupil sizes and shapes, often among animals that occupy optically similar environments, are poorly understood. We aimed to quantify the diversity and evolution of pupil shapes among amphibians and test for potential correla...
Article
Until recently many historical museum specimens were largely inaccessible to genomic inquiry, but high‐throughput sequencing (HTS) approaches have allowed researchers to successfully sequence genomic DNA from dried and fluid‐preserved museum specimens. In addition to preserved specimens, many museums contain large series of allozyme supernatant sam...
Article
Full-text available
Uncovering convergent and divergent patterns of diversification is a major goal of evolutionary biology. On four Greater Antillean islands, Anolis lizards have convergently evolved sets of species with similar ecologies and morphologies (ecomorphs). However, it is unclear whether closely related anoles from Central and South America exhibit similar...
Chapter
Citation: Rödel, M.-O., Adum, G.B., Aruna, E., Assemian, N.E., Barej, M.F., Bell, R.C., Burger, M., Demare, G., Doherty-Bone, T., Doumbia, J., Ernst, R., Gonwouo, N.L., Hillers, A., Hirschfeld, M., Jongsma, G.F.M., Kouamé, N.G., Kpan, T.F., Mohneke, M., Nago, S.G.A., Ofori-Boateng, C., Onadeko, A., Pauwels, O.S.G., Sandberger-Loua, L., Segniagbeto,...
Article
A period of isolation in allopatry typically precedes local adaptation and subsequent divergence among lineages. Alternatively, locally adapted phenotypes may arise and persist in the face of gene flow, resulting in strong correlations between ecologically-relevant phenotypic variation and corresponding environmental gradients. Quantifying genetic,...
Article
Full-text available
A correction to this paper has been published: https://doi.org/10.1007/s10682-021-10109-w
Article
Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate repeated phenotypic patterns in different parts of a species’ range. We investigated whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in t...
Preprint
Until recently many historical museum specimens were largely inaccessible to genomic inquiry, but high-throughput sequencing (HTS) approaches have allowed researchers to successfully sequence genomic DNA from dried and fluid-preserved museum specimens. In addition to preserved specimens, many museums contain large series of allozyme supernatant sam...
Preprint
Full-text available
Many animals have complex life cycles where larval and adult forms have distinct ecologies and habitats that impose different demands on their sensory systems. While the adaptive decoupling hypothesis predicts reduced genetic correlations between life stages, how sensory systems adapt across life stages at the molecular level is not well understood...
Article
Full-text available
Animals with biphasic lifecycles often inhabit different visual environments across ontogeny. Many frogs and toads (Amphibia: Anura) have free-living aquatic larvae (tadpoles) that metamorphose into adults that inhabit a range of aquatic and terrestrial environments. Ecological differences influence eye size across species, but these relationships...
Chapter
After more than two centuries of tortoise exploitation by mariners, oil merchants, and colonists, the decline and disappearance of tortoises in the Galapagos Islands motivated several natural history museums to organize expeditions between the 1880s and 1930s to document and preserve Galapagos giant tortoise diversity before it was too late. The hi...
Preprint
Full-text available
Phenotypic variation among populations, as seen in the signaling traits of many species, provides an opportunity to test whether similar factors generate shared phenotypic patterns in different parts of a species’ range. We investigate whether genetic divergence, abiotic gradients, and sympatry with closely related species explain variation in the...
Article
Full-text available
Frogs and toads (Amphibia: Anura) display diverse ecologies and behaviours, which are often correlated with visual capacity in other vertebrates. Additionally, anurans exhibit a broad range of relative eye sizes, which have not previously been linked to ecological factors in this group. We measured relative investment in eye size and corneal size f...
Article
Surprisingly little is known about body‐size evolution within the most diverse amphibian order, anurans (frogs and toads), despite known effects of body size on the physiological, ecological, and life‐history traits of animals more generally. Here we examined anuran body‐size evolution among 2434 species with over 200 million years of shared evolut...
Article
Full-text available
The fungal pathogen Batrachochytrium dendrobatidis (Bd) is implicated in global declines of amphibian populations and has been documented in African specimens originally collected as far back as the 1930s. Numerous recent surveys focusing on regional pathogen prevalence have greatly increased the number of known occurrences of Bd in African species...
Article
DNA evidence is often critical for taxonomic studies; however, many historical type specimens lack corresponding genetic samples, which limits contemporary molecular research questions and may restrict conservation and management decisions. We conducted a pilot Type Locality Project to collect voucher specimens and genomic-grade samples from amphib...
Article
Full-text available
The Central African treefrog Leptopelis brevirostris has a characteristically short and vertically truncated snout, a tooth-like process at the centre of the mandible, and unlike most species of Leptopelis, eats terrestrial gastropods. Two morphologically similar species (L. crystallinoron and L. brevipes) have been described in sympatry with L. br...
Article
Although naturally heterogeneous environments can lead to mosaic hybrid zones, human-induced habitat fragmentation can also lead to environmental heterogeneity and hybridization. Here we quantify phenotypic and molecular divergence across a reed frog mosaic hybrid zone on São Tomé Island as a first step towards understanding the consequences of hyb...
Article
Aim Species with wide distributions spanning the African Guinean and Congolian rain forests are often composed of genetically distinct populations or cryptic species with geographic distributions that mirror the locations of the remaining forest habitats. We used phylogeographic inference and demographic model testing to evaluate diversification mo...
Article
Full-text available
Biodiversity loss is one major outcome of human-mediated ecosystem disturbance. One way that humans have triggered wildlife declines is by transporting disease-causing agents to remote areas of the world. Amphibians have been hit particularly hard by disease due in part to a globally distributed pathogenic chytrid fungus (Batrachochytrium dendrobat...
Article
Full-text available
Biodiversity loss is one major outcome of human-mediated ecosys- tem disturbance. One way that humans have triggered wildlife declines is by transporting disease-causing agents to remote areas of the world. Amphibians have been hit particularly hard by disease due in part to a globally distributed pathogenic chytrid fungus (Batrachochytrium dendrob...
Article
Theory predicts that sexually dimorphic traits under strong sexual selection, particularly those involved with intersexual signaling, can accelerate speciation and produce bursts of diversification. Sexual dichromatism (sexual dimorphism in color) is widely used as a proxy for sexual selection and is associated with rapid diversification in several...
Preprint
Full-text available
Theory predicts that sexually dimorphic traits under strong sexual selection, particularly those involved with intersexual signaling, can accelerate speciation and produce bursts of diversification. Sexual dichromatism (sexual dimorphism in color) is widely used as a proxy for sexual selection and is associated with rapid diversification in several...
Article
Full-text available
Aim To investigate how putative barriers, forest refugia, and ecological gradients across the lower Guineo‐Congolian rain forest shape genetic and phenotypic divergence in the leaf‐folding frog Afrixalus paradorsalis, and examine the role of adjacent land bridge and sky‐islands in diversification. Location The Lower Guineo‐Congolian Forest, the Ca...
Article
Full-text available
Differences in mating signals among incipient species are an important mechanism driving reproductive isolation and speciation. Here, we investigate male advertisement call divergence across a radiation of reed frogs from the Gulf of Guinea archipelago and the most closely related species on the African continent (Hyperolius olivaceus). The two spe...
Article
Full-text available
The fungal pathogen Batrachochytrium dendrobatidis (Bd) infects hundreds of amphibian species and is implicated in global amphibian declines. Bd is comprised of several lineages that differ in pathogenicity, thus, identifying which Bd strains are present in a given amphibian community is essential for understanding host–pathogen dynamics. The prese...
Article
Full-text available
Dynamic sexual dichromatism is a temporary colour change between the sexes and has evolved independently in a wide range of anurans, many of which are explosive breeders wherein males physically compete for access to females. Behavioural studies in a few species indicate that dynamic dichromatism functions as a visual signal in large breeding aggre...
Article
Organismal traits interact with environmental variation to mediate how species respond to shared landscapes. Thus, differences in traits related to dispersal ability or physiological tolerance may result in phylogeographic discordance among co-distributed taxa, even when they are responding to common barriers. We quantified climatic suitability and...
Article
Full-text available
I describe a new species of reed frog (Hyperolius: Hyperoliidae) from the island of Príncipe in the Gulf of Guinea archipelago. The new species is within the Hyperolius cinnamomeoventris species complex, which includes four described species: H. cinnamomeoventris, H. veithi, H. molleri, and H. thomensis. The new species is sexually monochromatic (m...
Article
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Estimating phylogenetic trees is an important problem in evolutionary biology, environmental policy and medicine. Although trees are estimated, their uncertainties are discarded by mathematicians working in tree space. Here we explicitly model the multivariate uncertainty of tree estimates. We consider both the cases where uncertainty information a...
Article
Full-text available
Frog reproductive modes are complex phenotypes that include egg/clutch characteristics, oviposition site, larval development, and sometimes, parental care. Two evident patterns in the evolution of these traits are the higher diversity of reproductive modes in the tropics and the apparent progression from aquatic to terrestrial reproduction, often a...
Article
Almost 30 y ago, the field of intraspecific phylogeography laid the foundation for spatially explicit and genealogically informed studies of population divergence. With new methods and markers, the focus in phylogeography shifted to previously unrecognized geographic genetic variation, thus reducing the attention paid to phenotypic variation in tho...
Article
Oceanic islands accumulate endemic species when new colonists diverge from source populations or by in situ diversification of resident island endemics. The relative importance of dispersal versus in situ speciation in generating diversity on islands varies with a number of archipelago characteristics including island size, age, and remoteness. Her...
Article
Fragmented landscapes resulting from anthropogenic habitat modification can have significant impacts on dispersal, gene flow, and persistence of wildlife populations. Therefore, quantifying population connectivity across a mosaic of habitats in highly modified landscapes is critical for the development of conservation management plans for threatene...
Article
AimTo infer the colonization history of reed frog species endemic to the oceanic islands of SAo Tome and Principe, Hyperolius molleri and H. thomensis, we quantified phylogeographical structure in the closely related H. cinnamomeoventris species complex, which is broadly distributed across continental Central Africa. LocationThe Lower Guineo-Congol...
Article
Torrent frogs of the genus Petropedetes Reichenow, 1874 as currently understood have a disjunct distribution with species endemic to West, Central or East Africa. We herein present a phylogenetic analysis including all but one of the currently described 12 species of the genus. Maximum Likelihood and Bayesian analyses of combined nuclear (rag1, SIA...
Article
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Wiliwili (Erythrina sandwicensis), an endemic Hawaiian dry forest tree species, is threatened by an invasive gall- forming wasp (Quadrastichus erythrinae) first detected in Hawai‘i in 2005. Eurytoma erythrinae, a predator of Q. erythrinae from Tanzania, was selected as a biological control agent and was released at sites throughout the Hawaiian Isl...
Article
Full-text available
Sexual dichromatism, a form of sexual dimorphism in which males and females differ in colour, is widespread in animals but has been predominantly studied in birds, fishes and butterflies. Moreover, although there are several proposed evolutionary mechanisms for sexual dichromatism in vertebrates, few studies have examined this phenomenon outside th...
Article
Aim We investigated how Pleistocene refugia and recent (c. 12,000 years ago) sea level incursions shaped genetic differentiation in mainland and island populations of the Scinax perpusillus treefrog group. Location Brazilian Atlantic Forest, São Paulo state, south-eastern Brazil. Methods Using mitochondrial and microsatellite loci, we examined popu...
Article
In many organisms, mating behavior occurs at a particular time of day, which may be important for avoiding mate competition or interspecific mating. Crickets of the Hawaiian genus Laupala exhibit an unusually protracted courtship in which males produce a series of nuptial gifts prior to the species-typical time of mating. Mating time is one of seve...
Article
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Though Pleistocene refugia are frequently cited as drivers of species diversification, comparisons of molecular divergence among sister species typically indicate a continuum of divergence times from the Late Miocene, rather than a clear pulse of speciation events at the Last Glacial Maximum. Community-scale inference methods that explicitly test f...
Article
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Amphibian chytridiomycosis is an infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd) that is implicated in the worldwide decline and extinction of amphibians. Africa has been proposed as a potential source for the global expansion of Bd, yet the distribution of Bd across the continent remains largely unexplored. Using quanti...