54 research outputs found
The inequality-resource curse of conflict: Heterogeneous effects of mineral deposit discoveries
Despite a sizeable literature, there is no consensus as to whether and how mineral resources are linked to conflict. In this paper, we estimate the relationship between giant mineral deposit discoveries and the intensity of armed conflict (measured by battle deaths) around the world in the post-war era. The impact of such discoveries is potentially heterogeneous with respect to mineral commodity type: metals with a low value-to-weight ratio are not easy to exploit and smuggle and will disproportionally aid governments in their counterinsurgency efforts and raise the opportunity cost of fighting, whereas the discovery of deposits of high value-to-weight ratio metals may increase incentives for rebellion and make insurgency feasible. The data indeed show discoveries of giant deposits to lower the intensity of conflict for low unitvalue ores, but giant discoveries increase the intensity of conflict for high unit-value minerals. We also show that discoveries in countries with high ethnic inequality increase conflict intensity to a greater extent than in countries with low ethnic inequality - this heterogeneity is likely due to grievances related to the distribution of resource rents and revenues
Trophic niche shifts and phenotypic trait evolution are largely decoupled in Australasian parrots
Background: Trophic shifts from one dietary niche to another have played major roles in reshaping the evolutionary
trajectories of a wide range of vertebrate groups, yet their consequences for morphological disparity and species
diversity differ among groups.
Methods: Here, we use phylogenetic comparative methods to examine whether the evolution of nectarivory and
other trophic shifts have driven predictable evolutionary pathways in Australasian psittaculid parrots in terms of ecological
traits such as body size, beak shape, and dispersal capacity.
Results: We found no evidence for an âearly-burstâ scenario of lineage or morphological diversification. The bestfitting
models indicate that trait evolution in this group is characterized by abrupt phenotypic shifts (evolutionary
jumps), with no sign of multiple phenotypic optima correlating with different trophic strategies. Thus, our results
point to the existence of weak directional selection and suggest that lineages may be evolving randomly or slowly
toward adaptive peaks they have not yet reached.
Conclusions: This study adds to a growing body of evidence indicating that the relationship between avian morphology
and feeding ecology may be more complex than usually assumed and highlights the importance of adding
more flexible models to the macroevolutionary toolbox.info:eu-repo/semantics/publishedVersio
Characterizing divergence through three adjacent Australian avian transition zones
Aim
The diversification of the Australian avifauna has been greatly influenced by prominent historical and modern barriers to dispersal. The aims of this study were to characterize the patterns of divergence in population pairs of meliphagoid birds across adjacent transition zones and characterize how well morphometric divergence, habitat association and taxonomic or species ranking can predict genetic divergence.
Location: Northern Queensland, Australia.
Methods
Genetic divergence between parental populations on either side of the three biogeographical barriers corresponding to three clusters of hybrid zones was characterized in 27 species complexes of meliphagoid birds using one mitochondrial, 23 autosomal and 12 Z chromosome loci collected from a sequence capture system. Within each species, we characterized morphometric divergence using wing, bill and tail measurements from museum samples. Lastly, we evaluated the predictive power of these morphometric measurements on genetic divergence.
Results
Population pairs on either side of a transition zone depict a wide range of genomic and morphometric divergence. For some systems, species exhibiting morphometric divergence show little to no genomic divergence, while, conversely, other species exhibiting little to no morphometric divergence may show clear genomic divergence. Species rank is shown to be the strongest predictor for genetic divergence, habitat is the next strongest predictor and morphometric divergence is the weakest predictor.
Main conclusions
The variation in divergence levels of population pairs affirms that transition zones are ideal natural experiments to study the speciation process. In particular, transition zones allow understanding of how genomic divergence accumulates during speciation. Additionally, standing species rank classifications mostly prove to be robust after genetic characterization. Lastly, the discordance between morphometric and genetic divergence suggests other non-morphometric phenotypic traits used to designate species rank, such as song or plumage, may play a more important role in predicting genetic divergence
The correct authorship and type locality of Melanocorypha leucoptera (Aves: Passeriformes, Alaudidae)
MlĂkovskĂœ (2013) proposed replacing the widely-used Melanocorypha leucoptera (Pallas, 1811) with Melanocorypha leucoptera (Hablizl, 1785) as the correct name for the White-winged Lark, with consequent shift in type locality from the IrtyĆĄ River-Baraba steppe region in south Siberia to the Crimea. This action breaches Art. 80.9 of the International Code of Zoological Nomenclature (ICZN 1999), hereafter "the Code". That article states that "no ruling given by the Commission in relation to a particular work, name, or nomenclatural act is to be set aside without the consent of the Commission". Melanocorypha leucoptera of Pallas (1811), as published in his Zoographia Rosso-Asiatica, was conserved explicitly in Opinion 403 of the Commission (ICZN 1956), and no consent to MlĂkovskĂœ's findings has been given since
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
A monograph of the family Atherospermataceae R.Br.
2 v. : ill.Thesis (Ph.D.) -- University of Adelaide, Dept. of Botany, 196
The Identity and Sources of Palaeornis Anthopeplus Lear, 1831, and P. Melanura Lear, 1832 (Regent Parrot), and Their Neotypification
Volume: 130Start Page: 219End Page: 22
The Name Stipiturus Malachurus Polionotum (Southern Emu wren) - Fixing of Spelling
Volume: 128Start Page: 71End Page: 7
- âŠ