Publications by authors named "Jon Fjeldsa"

Diversification mechanisms in Sub-Saharan Africa have long attracted research interest, with varying support for either allopatric or parapatric models of speciation. However, studies have seldom been performed across the entire continent, a scale which could elucidate the relative importance of allopatric and parapatric models of divergence. To shed light on continental-scale patterns of African biogeography and diversification, we investigated the historical demography of a bird with a continent-wide distribution in Sub-Saharan Africa, the Yellow-Rumped Tinkerbird, Pogoniulus bilineatus.

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Article Synopsis
  • Relationships among avian lineages remain unresolved due to factors like species diversity, phylogenetic methods, and selection of genomic regions.
  • An analysis of 363 bird species' genomes reveals a well-supported evolutionary tree but highlights significant discrepancies among certain groups.
  • Findings suggest that after the Cretaceous-Palaeogene extinction, birds experienced increased population size and diversification, which offers a new foundational understanding for future research in avian evolution.
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The rapid diversification and high species richness of flowering plants is regarded as 'Darwin's second abominable mystery'. Today the global spatiotemporal pattern of plant diversification remains elusive. Using a newly generated genus-level phylogeny and global distribution data for 14,244 flowering plant genera, we describe the diversification dynamics of angiosperms through space and time.

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  • - Natural history museums hold important specimens, samples, and data that help us understand the natural world.
  • - A recent commentary discusses the need for more compassionate collection methods for specimens in these museums.
  • - It raises the question of whether it's feasible to entirely stop the collection of whole animal specimens in the future.
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Anticipating species' responses to environmental change is a pressing mission in biodiversity conservation. Despite decades of research investigating how climate change may affect population sizes, historical context is lacking, and the traits that mediate demographic sensitivity to changing climate remain elusive. We use whole-genome sequence data to reconstruct the demographic histories of 263 bird species over the past million years and identify networks of interacting morphological and life history traits associated with changes in effective population size (N) in response to climate warming and cooling.

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Despite evidence of declining biosphere integrity, we currently lack understanding of how the functional diversity associated with changes in abundance among ecological communities has varied over time and before widespread human disturbances. We combine morphological, ecological, and life-history trait data for >260 extant bird species with genomic-based estimates of changing effective population size () to quantify demographic-based shifts in avian functional diversity over the past million years and under pre-anthropogenic climate warming. We show that functional diversity was relatively stable over this period, but underwent significant changes in some key areas of trait space due to changing species abundances.

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The immense concentrations of vertebrate species in tropical mountains remain a prominent but unexplained pattern in biogeography. A long-standing hypothesis suggests that montane biodiversity hotspots result from endemic species aggregating within ecologically stable localities. Here, the persistence of ancient lineages coincides with frequent speciation events, making such areas both 'cradles' (where new species arise) and 'museums' (where old species survive).

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Article Synopsis
  • - AVONET is a comprehensive dataset providing functional traits for all bird species, featuring data on ecological variables, morphological traits, and species' range sizes from over 90,000 individuals across 181 countries.
  • - The dataset includes both raw measurements and summarized species averages in multiple taxonomic formats, enabling integration with phylogenies, geographical maps, and conservation status information.
  • - AVONET aims to enhance research in evolutionary biology and ecology by offering detailed insights into biodiversity, facilitating the testing of theories and models related to global change.
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  • Scientists are studying bird genomes to learn more about their diversity and evolution, analyzing 363 bird genomes from nearly all bird families for a big project called Bird 10,000 Genomes (B10K).
  • By using advanced methods, they can compare DNA more effectively, finding new patterns and understanding how different bird species are related.
  • This research helps improve our understanding of how birds evolve and can also aid in protecting them in the future.
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A new classification is proposed for the subfamily Fluvicolinae in the New World Flycatchers (Tyrannidae), based on the results of a previously published phylogeny including more than 90% of the species. In this classification we propose one new family level name (Ochthoecini) and one new generic name (Scotomyias). We also resurrect three genera (Heteroxolmis, Pyrope and Nengetus) and subsume five (Tumbezia, Lathrotriccus, Polioxolmis, Neoxolmis and Myiotheretes) into other genera to align the classification with the current understanding of phylogenetic relationships in Fluvicolinae.

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Strong relationships between morphological and ecological characters are commonly predicted to reflect the association between form and function, with this hypothesis being well supported in restricted taxonomic and geographical contexts. Conversely, among broader sets of species, ecological variables have been shown to have limited power to explain morphological variation. To understand these apparent discrepancies, for a large and globally distributed passerine radiation, we test whether (a) the character states of four ecological variables (foraging mode, diet, strata and habitat) have different morphological optima, (b) ecological variables explain substantial variance in morphology and (c) ecological character states can be accurately predicted from morphology.

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The great auk was once abundant and distributed across the North Atlantic. It is now extinct, having been heavily exploited for its eggs, meat, and feathers. We investigated the impact of human hunting on its demise by integrating genetic data, GPS-based ocean current data, and analyses of population viability.

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Aim: To document the species richness patterns of breeding birds along elevational gradients and explore its drivers in the Horn of Africa region.

Location: Horn of Africa region.

Taxon: Breeding birds.

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Mountain regions are unusually biodiverse, with rich aggregations of small-ranged species that form centers of endemism. Mountains play an array of roles for Earth's biodiversity and affect neighboring lowlands through biotic interchange, changes in regional climate, and nutrient runoff. The high biodiversity of certain mountains reflects the interplay of multiple evolutionary mechanisms: enhanced speciation rates with distinct opportunities for coexistence and persistence of lineages, shaped by long-term climatic changes interacting with topographically dynamic landscapes.

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Mountains contribute disproportionately to the terrestrial biodiversity of Earth, especially in the tropics, where they host hotspots of extraordinary and puzzling richness. With about 25% of all land area, mountain regions are home to more than 85% of the world's species of amphibians, birds, and mammals, many entirely restricted to mountains. Biodiversity varies markedly among these regions.

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The accumulation of exceptional ecological diversity within a lineage is a key feature of adaptive radiation resulting from diversification associated with the subdivision of previously underutilized resources. The invasion of unoccupied niche space is predicted to be a key determinant of adaptive diversification, and this process may be particularly important if the diversity of competing lineages within the area, in which the radiation unfolds, is already high. Here, we test whether the evolution of nectarivory resulted in significantly higher rates of morphological evolution, more extensive morphological disparity, and a heightened build-up of sympatric species diversity in a large adaptive radiation of passerine birds (the honeyeaters, about 190 species) that have diversified extensively throughout continental and insular settings.

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Why diversification rates vary so extensively across the tree of life remains an important yet unresolved issue in biology. Two prominent and potentially independent factors proposed to explain these trends reflect the capacity of lineages to expand into new areas of (i) geographical or (ii) ecological space. Here, we present the first global assessment of how diversification rates vary as a consequence of geographical and ecological expansion, studying these trends among 15 speciose passerine families (together approximately 750 species) using phylogenetic path analysis.

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The babblers are a diverse group of passerine birds comprising 452 species. The group was long regarded as a "scrap basket" in taxonomic classification schemes. Although several studies have assessed the phylogenetic relationships for subsets of babblers during the past two decades, a comprehensive phylogeny of this group has been lacking.

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We describe a new species of drongo in the Square-tailed Drongo (Dicrurus ludwigii) complex using a combination of biometric and genetic data. The new species differs from previously described taxa in the Square-tailed Drongo complex by possessing a significantly heavier bill and via substantial genetic divergence (6.7%) from its sister-species D.

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  • The family Locustellidae, known as grassbirds and allies, consists of 62 species spread across 11 genera, and this study analyzed 59 of these species to understand their evolutionary relationships.
  • The findings showed significant discrepancies in existing classifications, revealing that several previously recognized genera are not monophyletic, particularly emphasizing the scattered nature of the Megalurus genus.
  • The study suggests a need for taxonomic revision and identifies non-monophyletic species complexes, indicating possible underestimation of species diversity in the Locustellidae family.
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Detailed knowledge of species limits is an essential component of the study of biodiversity. Although accurate species delimitation usually requires detailed knowledge of both genetic and phenotypic variation, such variation may be limited or unavailable for some groups. In this study, we reconstruct a molecular phylogeny for all currently recognized species and subspecies of Australasian shrikethrushes (Colluricincla), including the first sequences of the poorly known C.

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Our objective was to elucidate the biogeography and speciation patterns in an entire avian family, which shows a complex pattern of overlapping and nonoverlapping geographical distributions, and much variation in plumage, but less in size and structure. We estimated the phylogeny and divergence times for all of the world's species of based on multiple genetic loci, and analyzed morphometric divergence and biogeographical history. The common ancestor of was present in the Sino-Himalayan Mountains or these mountains and Central Asia-Mongolia more than 9 million years ago (mya), but a burst of speciations took place during the mid-Pliocene to early Pleistocene.

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