Jon Fjeldså

• University of Copenhagen

Understanding the genetic diversity–area relationship (GAR) is essential for comprehending how species adapt to environmental changes, as genetic diversity is an indicator of a species' adaptive potential. Variation in environmental adaptation capacity exists among species and animal taxa with different distribution areas, highlighting the importan...

Wu et al. (1) conducted a phylogenomic analysis resulting in a new time frame for the diversification of modern birds, concluding that the rapid radiation of Neoaves occurred well before the Cretaceous–Paleogene (K–Pg) extinction event and that this catastrophic event did not affect their diversification dynamics. Here, we show that the divergence...

Despite tremendous efforts in the past decades, relationships among main avian lineages remain heavily debated without a clear resolution. Discrepancies have been attributed to diversity of species sampled, phylogenetic method and the choice of genomic regions1–3. Here we address these issues by analysing the genomes of 363 bird species⁴ (218 taxon...

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 d...

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.

High mountain habitats are globally important for biodiversity. At least 12% of birds worldwide breed at or above the treeline, many of which are endemic species or species of conservation concern. However, due to the challenges of studying mountain birds in difficult-to-access habitats, little is known about their status and trends. This book prov...

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...

The Eastern Arc Mountains of Tanzania and Kenya, a montane archipelago of 13 uplifted fault blocks (sky islands) isolated by lowland arid savanna, are a center of exceptional biological endemism. Under the influence of humid winds from the Indian Ocean, forests and associated species may have persisted in this region since the final uplift of these...

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 genomi...

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 spe...

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 which mediate demographic sensitivity to changing climate remain elusive. We use whole-genome sequence data...

The cover image is based on the Letter AVONET: morphological, ecological and geographical data for all birds by Tobias et al., https://doi.org/10.1111/ele.13898. The sword‐billed hummingbird (Ensifera ensifera) is exquisitely adapted to its trophic niche as an aerial pollinator of flowerings plants (angiosperms) in the high Andes. A new global data...

Functional traits offer a rich quantitative framework for developing and testing theories in evolutionary biology, ecology and ecosystem science. However, the potential of functional traits to drive theoretical advances and refine models of global change can only be fully realised when species-level information is complete. Here we present the AVON...

Africa’s montane areas are broken up into several large and small units, each isolated as forest-capped “sky islands” in a “sea” of dry lowland savanna. Many elements of their biota, including montane forest birds, are shared across several disjunct mountains, yet it has been difficult to rigorously define an Afromontane forest avifauna, or determi...

The presence of two undescribed cisticola warblers in the marshes of the Kilombero floodplain in central Tanzania has been known since the 1980s and these putative new species have been illustrated in field guides on African birds, although with no formal name. Here we name both species, based on two museum specimens collected in 1961 and recently...

Genetic diversity is an essential component of biodiversity. Developing robust quantification methods is critically important in depicting the genetic diversity underlying the geographical distributions of species, especially for the sequence data with unequal lengths. Traditional calculation of genetic diversity depends on sequences of equal lengt...

A Correction to this paper has been published: https://doi.org/10.1038/s41586-021-03473-8.

Aim: Across a variety of taxonomic scales, species diversity is unevenly distributed among its constituent units, and clades with few species are more common than expected assuming homogeneous rates of speciation and extinction among lineages. In order to explain the prevalence of species-poor families among a global and species-rich radiation of p...

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity1,2,3,4. Sparse taxon sampling has previously been proposed to confound phylogenetic inference5, and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic...

Few studies have quantified the extent of genetic differentiation within widely distributed polytypic African bird species with disjunct ranges. Current knowledge indicates that high levels of genetic differentiation are found for such lineages but generalisation of the pattern requires further comparisons with other co‐distributed taxa. We assesse...

Aim The Pleistocene glacial cycles play a prominent role in shaping phylogeographical patterns of organisms, while few studies have focused on the regional difference of glacial effects. By acquiring comprehensive knowledge of the origin, diversification and historical demography of an intensively studied passerine species complex, Great Tit, we ai...

Aim Variation in species diversity among different geographical areas may result from differences in speciation and extinction rates, immigration and time for diversification. An area with high species diversity may be the result of a high net diversification rate, multiple immigration events from adjacent regions, and a long time available for the...

We studied the phylogeny, biogeography, and diversification of suboscine passerines in the genus Scytalopus (Rhinocryptidae), a widespread, species-rich, and taxonomically challenging group of Neotropical birds. We analyzed nuclear (exons, regions flanking ultraconserved elements) and mitochondrial (ND2) DNA sequence data for a taxonomically and ge...