Measures of success in a class of evolutionary models with fixed population size and structure

We investigate a class of evolutionary models, encompassing many established models of well-mixed and spatially structured populations. Models in this class have fixed population size and structure. Evolution proceeds as a Markov chain, with birth and death probabilities dependent on the current population state. Starting from basic assumptions, we show how the asymptotic (long-term) behavior of the evolutionary process can be characterized by probability distributions over the set of possible states. We then define and compare three quantities characterizing evolutionary success: fixation probability, expected frequency, and expected change due to selection. We show that these quantities yield the same conditions for success in the limit of low mutation rate, but may disagree when mutation is present. As part of our analysis, we derive versions of the Price equation and the replicator equation that describe the asymptotic behavior of the entire evolutionary process, rather than the change from a single state. We illustrate our results using the frequency-dependent Moran process and the birth–death process on graphs as examples. Our broader aim is to spearhead a new approach to evolutionary theory, in which general principles of evolution are proven as mathematical theorems from axioms.     

Phosphodiesterase 10A Is Tethered to a Synaptic Signaling Complex in Striatum

Phosphodiesterase 10A (PDE10A) is a dual substrate PDE that can hydrolyze both cGMP and cAMP. In brain, PDE10A is almost exclusively expressed in the striatum. In several studies, PDE10A has been implicated in regulation of striatal output using either specific inhibitors or PDE10A knock-out mice and has been suggested as a promising target for novel antipsychotic drugs. In striatal medium spiny neurons, PDE10A is localized at the plasma membrane and in dendritic spines close to postsynaptic densities. In the present study, we identify PDE10A as the major cAMP PDE in mouse striatum and monitor PKA-dependent PDE10A phosphorylation. With recombinantly expressed PDE10A we demonstrate that phosphorylation does not alter PDE10A activity. In striatum, PDE10A was found to be associated with the A kinase anchoring protein AKAP150 suggesting the existence of a multiprotein signaling complex localizing PDE10A to a specific functional context at synaptic membranes. Furthermore, the cAMP effector PKA, the NMDA receptor subunits NR2A and -B, as well as PSD95, were tethered to the complex. In agreement, PDE10A was almost exclusively found in multiprotein complexes as indicated by migration in high molecular weight fractions in size exclusion chromatography. Finally, affinity of PDE10A to the signaling complexes formed around AKAP150 was reduced by PDE10A phosphorylation. The data indicate that phosphorylation of PDE10 has an impact on the interaction with other signaling proteins and adds an additional line of complexity to the role of PDE10 in regulation of synaptic transmission.     

Monitoring the impact of climate change on biodiversity: The challenge of megadiverse Mediterranean climate ecosystems

The Mediterranean climate regions of Western Australia and South Africa are recognized as global hot spots of diversity. Both are threatened by climate changes that are projected to have significant impacts on the quantity and variability of rainfall and affect key ecosystem drivers (e.g. fire regimes). This poses significant challenges to monitoring programs designed to detect these impacts. Effective monitoring of the impact of climate change on biodiversity (rather than individual species) requires a cross‐disciplinary, coordinated, focused and integrated approach. Ideally, this should involve a multidisciplinary team of specialists working to a common plan on the same set of plots. The contributions of ‘citizen scientists’ are potentially useful if well managed. Biodiversity per se (across all kingdoms of life, and including the levels of the gene, population and community) should be monitored, especially key species interactions and processes. Forestcheck is an example of such a program which has been applied in forests in south‐west Western Australia since 2001. In concert with measuring the direct impact of climate change on biodiversity and the indirect impact of factors that affect biodiversity (such as disease, invasive species, fire regime and habitat removal), there is a need for a proactive focus on creating, maintaining and monitoring resilience to climate change impacts in ecosystems. It is also necessary to monitor the effectiveness of management actions such as vegetation thinning, changes in fire regimes, species translocations and revegetation of farmland to link isolated protected areas in agricultural landscapes, remnant native vegetation in rangelands and extensive protected areas. A pluralist approach is recommended. This should include natural experiments, matched photographs where available, passive adaptive management, active adaptive management and traditional reductionist scientific investigation. The resultant synthesis of information from this range of sources is likely to be a predictive, robust and credible record of historical change.     

Revision of the lygaeid genera Porta and Primierus (Hemiptera: Heteroptera), with the description of a new genus of Ozophorini from Papua New Guinea (Hemiptera)

Abstract. The lygaeid genera Porta Distant and Primierus Distant are revised and placed in the tribe Ozophorini. A key to all species is included. Phylogenetic relationships are discussed and a cladogram constructed. The following new species are described: Porta illustris (Philippines); P.longipes (Sabah), Primierus quadrispinosus (Sarawak, Sabah, Malaya), P.venustus (Sabah), and P.longirostris (Thailand). Gressittocoris intimidator is described as a new genus and species of Ozophorini from Papua New Guinea. Porta gracilis Distant is reported from Sabah, Sumatra and Thailand for the first time and records of P.gracilis from the Philippines are referred to Porta illustris sp.n. Illustrations include details of the genitalia and dorsal views of Primierus quadrispinosus, P.longirostris and Gressittocoris intimidator.