Publications by authors named "Krystal A Tolley"

Exploration of the microbiome has been referred to as a final frontier in biological research. This is due to its precedence for generating insights on the holistic functioning of organismal biology by exploring the interactions between hosts and their associated symbiotic organisms. The microbiomes of many vertebrate groups still require exploration to advance current knowledge and fill previous knowledge gaps.

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Barking geckos (genus Ptenopus) are terrestrial, burrowing lizards endemic to southern Africa, currently with three recognised species. Two species are range-restricted (P. kochi and P.

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  • The study explores whether single mitochondrial genes can effectively serve as substitutes for full mitogenomes in creating phylogenetic trees, focusing on southern African dwarf chameleons.
  • It finds that several individual mitochondrial genes provide similar phylogenetic results to the complete mitogenome, indicating their reliability as markers for phylogenetic analysis.
  • Conversely, a commonly used short gene fragment produced differing results and should be avoided in future phylogenetic research.
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Recent biological surveys of ancient inselbergs in southern Malawi and northern Mozambique have led to the discovery and description of many species new to science, and overlapping centres of endemism across multiple taxa. Combining these endemic taxa with data on geology and climate, we propose the 'South East Africa Montane Archipelago' (SEAMA) as a distinct ecoregion of global biological importance. The ecoregion encompasses 30 granitic inselbergs reaching > 1000 m above sea level, hosting the largest (Mt Mabu) and smallest (Mt Lico) mid-elevation rainforests in southern Africa, as well as biologically unique montane grasslands.

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Sub-Saharan Africa is under-represented in global biodiversity datasets, particularly regarding the impact of land use on species' population abundances. Drawing on recent advances in expert elicitation to ensure data consistency, 200 experts were convened using a modified-Delphi process to estimate 'intactness scores': the remaining proportion of an 'intact' reference population of a species group in a particular land use, on a scale from 0 (no remaining individuals) to 1 (same abundance as the reference) and, in rare cases, to 2 (populations that thrive in human-modified landscapes). The resulting bii4africa dataset contains intactness scores representing terrestrial vertebrates (tetrapods: ±5,400 amphibians, reptiles, birds, mammals) and vascular plants (±45,000 forbs, graminoids, trees, shrubs) in sub-Saharan Africa across the region's major land uses (urban, cropland, rangeland, plantation, protected, etc.

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  • A database was created to track lost and rediscovered tetrapod species, revealing a faster loss rate than rediscovery, especially for amphibians, birds, and reptiles.
  • The study highlights specific regions and species types that are at risk of being lost, which can help focus conservation efforts on finding these species.
  • It identifies factors that affect rediscovery chances, indicating that some species may remain hidden due to their characteristics or habitats, while others are more likely extinct, guiding future conservation strategies.
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We conducted a study on interpopulation variation of colour patterns in two congeneric chameleon species, which have an analogous life history. Both species are able to rapidly change colour pattern, and their context-dependent colour patterns often vary across a wide geographical range. Specifically, we tested four hypotheses that can explain the observed interpopulation variation of colour patterns by a series of behavioural field trials where the colour patterns of individuals were recorded and later analysed by a deep neural network algorithm.

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A complete and high-quality reference genome has become a fundamental tool for the study of functional, comparative, and evolutionary genomics. However, efforts to produce high-quality genomes for African taxa are lagging given the limited access to sufficient resources and technologies. The southern African dwarf chameleons (Bradypodion) are a relatively young lineage, with a large body of evidence demonstrating the highly adaptive capacity of these lizards.

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Molecular phylogenetics and the application of species delimitation methods have proven useful in addressing limitations associated with morphology based taxonomy and have highlighted the inconsistencies in the current taxonomy for many groups. For example, the genus Chamaeleo, which comprises 14 species with large distributions across mainland Africa and parts of Eurasia, exhibits relatively minor phenotypic differentiation between species, leading to speculation regarding the presence of cryptic diversity in the genus. Therefore, the aims of the present study were to construct a robust and comprehensive phylogeny of the genus and highlight potential species-level cryptic diversity.

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Article Synopsis
  • A comprehensive assessment of reptile extinction risks reveals that 21.1% of reptile species, or 1,829 out of 10,196, are threatened, highlighting the urgent need for conservation strategies amidst global extinction crises.
  • Similar to other tetrapods like amphibians, mammals, and birds, reptiles face threats from agriculture, logging, urban development, and invasive species, with forest-dwelling reptiles being at a higher risk than those in arid environments.
  • Although some reptile species need immediate action for conservation, broader efforts targeting other tetrapods, such as habitat protection and managing invasive species, could also benefit many reptile species.
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Open access to sequence data is a cornerstone of biology and biodiversity research, but has created tension under the United Nations Convention on Biological Diversity (CBD). Policy decisions could compromise research and development, unless a practical multilateral solution is implemented.

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Detecting occupied sites of rare species, and estimating the probability that all occupied sites are known within a given area, are desired outcomes for many ecological or conservation projects. Examples include managing all occupied sites of a threatened species or eradicating an emerging invader. Occupied sites may remain undetected because (1) sites where the species potentially occurs had not been searched, and (2) the species could have been overlooked in the searched sites.

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The genus Pedioplanis reaches its northernmost limit in western Angola, where it is represented by three species, Pedioplanis benguelensis, P. haackei and P. huntleyi.

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Background: The African continent is comprised of several different biomes, although savanna is the most prevalent. The current heterogeneous landscape was formed through long-term vegetation shifts as a result of the global cooling trend since the Oligocene epoch. The overwhelming trend was a shift from primarily forest, to primarily savanna.

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  • Burrowing is a common behavior in vertebrates that provides advantages and challenges, particularly the energy costs associated with digging.
  • Scolecophidians, a type of subterranean snake, show diversity in their burrowing methods, with typhlopids believed to generate their own burrows unlike some other related snakes.
  • Research reveals that typhlopids can produce greater push forces than other burrowing snakes of similar size, indicating distinct differences in their anatomy and muscle use related to burrowing mechanics.
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Tropical Africa is home to an astonishing biodiversity occurring in a variety of ecosystems. Past climatic change and geological events have impacted the evolution and diversification of this biodiversity. During the last two decades, around 90 dated molecular phylogenies of different clades across animals and plants have been published leading to an increased understanding of the diversification and speciation processes generating tropical African biodiversity.

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A new species of tree snake Dipsadoboa montisilva Branch, Conradie Tolley sp. nov. (Serpentes: Colubridae) is described from the 'sky islands' of Mount Mabu and Mount Ribáuè in northern Mozambique.

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Previous studies on leaf-tailed geckos of the genus Uroplatus identified a lineage from the Ankarana karst massif in northern Madagascar as genetically highly divergent, but only fragmentary information was available on these geckos. Here, we provide an integrative analysis based on molecular and morphological data, including a newly collected specimen from this locality. Phylogenetic analysis placed the Ankarana lineage sister to U.

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A horizon scan was conducted to identify emerging and intensifying issues for biodiversity conservation in South Africa over the next 5-10 years. South African biodiversity experts submitted 63 issues of which ten were identified as priorities using the Delphi method. These priority issues were then plotted along axes of social agreement and scientific certainty, to ascertain whether issues might be "simple" (amenable to solutions from science alone), "complicated" (socially agreed upon but technically complicated), "complex" (scientifically challenging and significant levels of social disagreement) or "chaotic" (high social disagreement and highly scientifically challenging).

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Scaling evolutionary trees to time is essential for understanding the origins of clades. Recently developed methods allow including the entire fossil record known for the group of interest and eliminated the need for specifying prior distributions for node ages. Here we apply the fossilized birth-death (FBD) approach to reconstruct the diversification timeline of the viperines (subfamily Viperinae).

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The Heaviside's (or Benguela) dolphin (Cephalorhynchus heavisidii) is endemic to the west coast of southern Africa. The present study investigated the population genetic structure across a large portion of the species distribution using mitochondrial control region and nuclear (microsatellite) markers. A total of 395 biopsy skin samples were analyzed; they were collected from free-ranging Heaviside's dolphins in 7 locations along 1650 km of coast between Table Bay, South Africa and Walvis Bay, Namibia.

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The African green and bush snakes of the genus Philothamnus currently comprises 21 species and three subspecies and occurs throughout sub-Saharan Africa. The genus has been the subject of previous taxonomic revisions based on traditional morphological characters and limited genetic assessment, and may not reflect their evolutionary history. Indeed, previous findings based on phylogenetics show discordant results of interspecific relationships and question the monophyly of the genus, although taxon sampling has been limited to date.

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Age-specific survival and reproduction are closely linked to fitness and therefore subject to strong selection that typically limits their variability within species. Furthermore, adult survival rate in vertebrate populations is typically less variable over time than other life-history traits, such as fecundity or recruitment. Hence, adult survival is often conserved within a population over time, compared to the variation in survival found across taxa.

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Article Synopsis
  • Biogeographic barriers in the Central African highlands limit gene flow among species, influencing divergence patterns across various populations.
  • A study on the Central African pygmy chameleon identified it as a complex of at least six distinct species, highlighting unrecognized cryptic diversity.
  • Findings suggest that both geographical isolation and elevational differentiation contributed to these species' divergence, with significant diversification occurring during the Miocene, emphasizing the need to explore hidden diversity in widespread species for better understanding of biodiversity patterns.
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