The provision of winter bird food by the English Environmental Stewardship scheme

Environmental Stewardship (ES) is the main mechanism for reversing the decline in farmland birds in England, and includes a range of options designed to provide winter foraging for seed‐eating species. We estimated granivorous songbird densities on ES options designed to provide winter food, on farms within the Entry Level (ELS) or Higher Level (HLS) strata of ES. ES Wild Bird Mixtures (WBMs) hosted higher densities and a wider range of granivores than non‐ES game covers, although in East Anglia the enhanced HLS WBM was used no more than the basic ELS WBM. In the West Midlands there were low densities of granivores on all WBMs and game covers. The widespread ELS WBM appeared to provide little food for buntings but supported finches, partially through greater weed burdens. There was a weak, non‐significant trend for Skylarks Alauda arvensis to make greater use of ELS cereal stubbles than non‐ES stubbles, possibly because of post‐harvest herbicide restrictions allowing overwinter weed growth. At the field scale, this work demonstrates that although some ES options provide winter food resources for birds, there is limited evidence for additional benefits of Higher Level vs. Entry Level Stewardship to wintering farmland songbirds.     

Perspectives from early career researchers on the publication process in ecology – a response to Statzner & Resh (2010)

1. Two senior ecologists summarised their experience of the scientific publication process ( Statzner & Resh, Freshwater Biology, 2010 ; 55 , 2639) to generate discussion, particularly among early career researchers (ECRs). As a group of eight ECRs, we comment on the six trends they described. 2. We generally agree with most of the trends identified by Statzner & Resh (2010) , but also highlight a number of divergent perspectives and provide recommendations for change. Trends of particular concern are the use of inappropriate metrics to evaluate research quality (e.g. impact factor) and the salami slicing of papers to increase paper count. We advocate a transparent and comprehensive system for evaluating the research. 3. We stress the importance of impartiality and independence in the peer review process. We therefore suggest implementation of double‐blind review and quality control measures for reviewers and possibly editors. Besides such structural changes, editors should be confident to overrule biased reviewer recommendations, while reviewers should provide helpful reviews but be explicit if a submission does not meet quality standards. Authors should always conduct a thorough literature search and acknowledge historical scientific ideas and methods. Additionally, authors should report low‐quality copy editing and reviews to the editors. 4. Both early and late career researchers should jointly implement these recommendations to reverse the negative trends identified by Statzner & Resh (2010) . However, more senior scientists will always have to take the lead with respect to structural changes in the publication system given that they occupy the majority of decision‐making positions.     

Evolution of venom delivery structures in madtom catfishes (Siluriformes: Ictaluridae)

The use of venom to subdue prey or deter predators has evolved multiple times in numerous animal lineages. Catfishes represent one of the most easily recognized, but least studied groups of venomous fishes. Venom glands surround spines on the dorsal and pectoral fins that serve as venom delivery structures. Species of madtom catfishes in the genus Noturus were found to each have one of four venom delivery morphologies: (1) smooth spine with no venom gland; (2) smooth spine with venom gland associated with shaft of spine; (3) serrated spine with venom gland associated with shaft of spine; and (4) serrated spine with venom gland associated with shaft of spine and posterior serrations. Analyses accounting for the phylogenetic history of Noturus species suggest that a serrated pectoral spine with a venom gland is the ancestral condition for the genus. The presence of serrations and a venom gland have been largely conserved among Noturus species, but sting morphology has changed at least five times within the genus. Four of these changes have resulted in a loss of morphological complexity, including the loss of posterior serrations, loss of venom glands associated with the posterior serrations, and one complete loss of the venom gland. © 2010 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 102 , 115–129.     

Beyond the prolegomenon: a molecular phylogeny of the Australian camaenid land snail radiation

From an analysis of over 900 specimens of camaenid land snails, we have assembled a molecular phylogeny of 327 tips covering > 70% genera across the entire continent of Australia and including > 90% of eastern species. Our approach emphasizes sampling to identify lineage flocks from populations down to build a hierarchical gene‐by‐taxa tapestry or supermatrix dataset using three mitochondrial genes, then analysed with Markov chain Monte Carlo and fast maximum likelihood methods. Similarity amongst taxa set results suggests missing data cause only minor distortions. This is supplemented by a separate higher level 28S rDNA phylogeny for a global scale perspective. The shallow divergence of Australasian forms, and their nesting within South‐East Asian groups within the Helicoidea supergroup extending from Europe to North America, is consistent with the Solem hypothesis of Laurasian immigration of c. Miocene origin, and so being more than 400 species in 80‐plus genera spread across the continent of Australia from rainforest to desert, forms an immense radiation. There is a major distinction between eastern and western lineages, with some key exceptions. Finer scale patterns of relictual endemics indicate that many ancestral lineages were in place before the major decline and breakup of the Tertiary mesic forest realm that once dominated Gondwanan Australia, and so chart the phylogenetic turnover of ecosystem change from mesic to xeric. The various higher classification schemes proposed all founder on the sheer scale of this radiation. Of 30 polytypic genera tested, at least 18 are not monophyletic, highlighting (1) the repeated radiation of shell forms, and (2) that the current higher taxonomy is unacceptable. Here we provide a phylogenetic and biogeographically condign arrangement as the basis for future elaborations. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 161 , 531–572.     

Phylogeography of the snakeskin chiton Sypharochiton pelliserpentis (Mollusca: Polyplacophora) around New Zealand: are seasonal near‐shore upwelling events a dynamic barrier to gene flow?

We present a phylogeographic study of the New Zealand and Australian intertidal chiton Sypharochiton pelliserpentis that was conducted to ascertain levels of population connectivity and to investigate the effect of previously hypothesized general phylogeographic boundaries. The analysis incorporated both cytochrome oxidase subunit 1 sequence data (approximately 700 bp) and RFLP data from 29 populations around New Zealand, and from one Australian population, for a total of N = 472. The major population structure observed was a strong disjunction between northern and southern populations (Φ_ST = 0.47), with the genetic breaks located at Cloudy/Clifford Bay and Farewell Spit, at the northern tip of the South Island. This finding corresponds with a common phylogeographic barrier observed in a number of other marine invertebrates, highlighting its significance and ubiquity. A third barrier to gene flow was identified between Spirits Bay and Ahipara, around the northern tip of the North Island. All three of these areas that exhibit significant population disjunctions have strong near‐shore upwelling along with water current movement offshore, and these features are prevalent during the time of year when S. pelliserpentis spawns. That these seasonal hydrographic patterns contribute to the population structuring of S. pelliserpentis is supported by comparison with other phylogeographic studies of marine invertebrates, where the strength of this barrier seems to correlate with spawning season. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 552–563.     

A benthic predatory fish does not cause selection on armour traits in three‐spined stickleback Gasterosteus aculeatus (Gasterosteiformes: Gasterosteidae)

Predation can promote divergence between prey populations and contribute to ecological speciation. In theory, predators can also constrain prey population divergence. In coastal British Columbia, Canada, Gasterosteus aculeatus (three‐spined stickleback) species pairs only occur in lakes with a single species of predatory fish: Oncorhynchus clarkii (the cutthroat trout). Similar lakes containing additional predatory fish species (Cottus asper, prickly sculpins; Oncorhynchus mykiss, rainbow trout) contain only single species of morphologically intermediate stickleback, suggesting that these predators prevent the coexistence of stickleback species pairs. We conducted a mesocosm experiment to investigate how prickly sculpins might constrain divergence, by quantifying their impact on survival and natural selection on antipredator (armour) traits in F₂ stickleback from a cross between ecologically divergent populations. We tested three hypotheses: (1) sculpin predation on sticklebacks reduces survival in a way that could result in their exclusion from certain niches; (2) sculpins compete with stickleback; (3) sculpins respond to prey vulnerabilities in similar ways to cutthroat trout, tending to constrain rather than to enhance divergence. We found that sculpins significantly reduce stickleback survival, that their presence per se does not reduce growth in stickleback, and that predation did not result in selection on any of the armour traits measured, or on gill raker length, which is an important trophic trait. These results tend to refute hypotheses (2) and (3), while supporting hypothesis (1). © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 877–885.     

Chilling to zero degrees disrupts pollen formation but not meiotic microtubule arrays in Triticum aestivum L.

Throughout the wheat‐growing regions of Australia, chilling temperatures below 2 °C occur periodically on consecutive nights during the period of floral development in spring wheat (Triticum aestivum L.). In this study, wheat plants showed significant reductions in fertility when exposed to prolonged chilling temperatures in controlled environment experiments. Among the cultivars tested, the Australian cultivars Kite and Hartog had among the lowest levels of seed set due to chilling and their responses were investigated further. The developmental stage at exposure, the chilling temperature and length of exposure all influenced the level of sterility. The early period of booting, and specifically the +4 cm auricle distance class, was the most sensitive and corresponded to meiosis within the anthers. The response of microtubules to chilling during meiosis in Hartog was monitored, but there was little difference between chilled and control plants. Other abnormalities, such as plasmolysis and cytomixis increased in frequency, were associated with death of developing pollen cells, and could contribute to loss of fertility. The potential for an above‐zero chilling sensitivity in Australian spring wheat varieties could have implications for exploring the tolerance of wheat flower development to chilling and freezing conditions in the field.     

Preference induction and the benefits of floral resources for a facultative florivore

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Molecular phylogeny of telenomine egg parasitoids (Hymenoptera: Platygastridae s.l.: Telenominae): evolution of host shifts and implications for classification

Parasitoid wasps of the subfamily Telenominae (Hymenoptera: Platygastroidea, Platygastridae) develop as immatures within the eggs of other insects (Lepidoptera, Hemiptera, Diptera and Neuroptera). Rearing records indicate that individual species are restricted to attack hosts within only one of these four main groups. We conducted a phylogenetic analysis of the group using sequence data from multiple genes (18S, 28S, COI, EF‐1α) to assess the pattern of shifts among host groups and to test the monophyly of and relationships among genera and species‐groups. Telenominae sensu Masner—that is, including only the nominate tribe Telenomini—is not monophyletic. Representatives of the Psix group of genera (Psix Kozlov & Lê and Paratelenomus Dodd) form a monophyletic group that is sister to Gryon Haliday (Scelioninae: Gryonini) and are excluded from the subfamily. The remaining telenomines are monophyletic. The genus Phanuromyia Dodd and the crassiclava group of Telenomus Haliday, both recorded as parasitoids of planthopper eggs (Hemiptera: Auchenorrhyncha, Fulgoroidea), form a monophyletic group that is sister to all other telenomines exclusive of the Psix group. Twenty‐nine species of the crassiclava and aradi groups of Telenomus are transferred to Phanuromyia as new combinations. Basal elements of the remaining species are all in groups reared from the eggs of true bugs (Heteroptera), primarily the stink bugs (Pentatomoidea) and seed bugs (Lygaeoidea). A shift to parasitism of lepidopteran eggs evolved within a single clade, occurring either one or two times. From this clade a small group of species, the Telenomus tabanivorus group, subsequently shifted to parasitism of egg masses of true flies (Tabanidae and Stratiomyiidae). Aholcus Kieffer and Platytelenomus Dodd both belong to the clade of lepidopteran parasitoids and are considered as junior synonyms of Telenomus (new synonymy for Aholcus). The monophyletic status of the two core genera, Telenomus and Trissolcus could not be resolved using these data. The phylogenetic pattern of host shifts suggests comparisons among taxa that may be fruitful in elucidating mechanisms by which parasitoids locate their hosts, the proximate factors that determine the host range, and the changes in these factors that influence host changes.     

Population genomics of wild and laboratory zebrafish (Danio rerio)

Understanding a wider range of genotype–phenotype associations can be achieved through ecological and evolutionary studies of traditional laboratory models. Here, we conducted the first large‐scale geographic analysis of genetic variation within and among wild zebrafish (Danio rerio) populations occurring in Nepal, India, and Bangladesh, and we genetically compared wild populations to several commonly used lab strains. We examined genetic variation at 1832 polymorphic EST‐based single nucleotide polymorphisms (SNPs) and the cytb mitochondrial gene in 13 wild populations and three lab strains. Natural populations were subdivided into three major mitochondrial DNA clades with an average among‐clade sequence divergence of 5.8%. SNPs revealed five major evolutionarily and genetically distinct groups with an overall F_ST of 0.170 (95% CI 0.105–0.254). These genetic groups corresponded to discrete geographic regions and appear to reflect isolation in refugia during past climate cycles. We detected 71 significantly divergent outlier loci (3.4%) and nine loci (0.5%) with significantly low F_ST values. Valleys of reduced heterozygosity, consistent with selective sweeps, surrounded six of the 71 outliers (8.5%). The lab strains formed two additional groups that were genetically distinct from all wild populations. An additional subset of outlier loci was consistent with domestication selection within lab strains. Substantial genetic variation that exists in zebrafish as a whole is missing from lab strains that we analysed. A combination of laboratory and field studies that incorporates genetic variation from divergent wild populations along with the wealth of molecular information available for this model organism provides an opportunity to advance our understanding of genetic influences on phenotypic variation for a vertebrate species.