The Qinghai-Tibetan Plateau (QTP) is the highest and one of the most extensive plateaus in the world. Phylogenetic, phylogeographic, and ecological studies support plant diversifications on the QTP through multiple mechanisms such as allopatric speciation via geographic isolation, climatic oscillations and divergences, pollinator-mediated isolation, diploid hybridization and introgression, and ...

Cyanogenic glucosides are present in many plants and their ability to liberate toxic HCN offers an immediate chemical defense response to herbivores and pathogens causing damage of the plant tissue. Countermeasures have evolved to overcome this type of defense and in some cases herbivores and pathogens are able to exploit the presence of cyanogenic glucosides to their own advantage. In plants, ...

this article examines the livelihood strategies of land scarce peasants in ethiopian. land scarce peasants have a limited livelihood security on a sustainable manner and bypassed by major development programmes. the study was centred on two sets of rationales. first, for those peasants who do not have sufficient farmland, agriculture provides only a limited portion of households’ livelihood sec...

We investigated the phylogeny and biogeography of the Rhinella marina group, using molecular, morphological, and skin-secretion data, contributing to an understanding of Neotropical faunal diversification. The maximum-parsimony and Bayesian analyzes of the combined data recovered a monophyletic R. marina group. Molecular dating based on Bayesian inferences and fossil calibration placed the earl...

Evolutionary diversifications are commonly attributed to the continued modifications of a conserved genetic toolkit of developmental pathways, such that complexity and convergence in organismal forms are assumed to be due to similarity in genetic mechanisms or environmental conditions. This approach, however, confounds the causes of organismal development with the causes of organismal differenc...

Rapid species diversifications provide fascinating insight into the development of biodiversity in time and space. Most biological radiations studied to date, for example that of cichlid fishes or Andean lupines, are confined to isolated geographical areas like lakes, islands or island-like regions. Using DNA sequence data of the ribosomal internal transcribed spacer (ITS) for many species of t...

Mass extinctions have played many evolutionary roles, involving differential survivorship or selectivity of taxa and traits, the disruption or preservation of evolutionary trends and ecosystem organization, and the promotion of taxonomic and morphological diversifications-often along unexpected trajectories-after the destruction or marginalization of once-dominant clades. The fossil record sugg...