Colonization history, ecological shifts and diversification in the evolution of endemic Galápagos weevils

Mitochondrial DNA sequence data were obtained for eight species of flightless Galapaganus endemic weevils and one winged close relative in order to study their colonization history and modes of diversification in the Galápagos Archipelago. Contrary to most other insular radiations, the phylogeny estimates we recovered for Galapaganus do not follow the progression rule of island biogeography. The penalized likelihood age estimates of colonization of the archipelago exceed the age of the emerged islands and underscore the potential role of now sunken seamounts for the early evolution of Galapaganus . The phylogeny proposes one intra-island origin for Galapaganus endemics, but monophyly tests suggest a larger contribution of in-situ speciation on older islands. Generalist habitat preferences were reconstructed as ancestral while shifts to highland habitats were reconstructed as having evolved independently on different islands. Magnitudes and patterns of diversification rate were found to differ between older and younger islands. Our analyses reveal that the colonization sequence of islands and timing of colonization of Galapaganus could be linked with the geological and volcanic history of the islands in a rather complex scenario. Even though most islands appear to have been colonized soon after their emergence, there are notable deviations from the pattern of sequential colonization expected under the progression rule when considering only the extant emerged islands. Patterns of diversification rate variation on older and younger islands correspond to the volcanic activity or remnants of such activity, while the pattern of independent evolution of restricted habitat preferences in different islands suggests that habitat shifts could also have contributed to species diversity in Galapaganus .     

Detecting biodiversity hotspots using species–area and endemics–area relationships: the case of butterflies

Using data of the Red Data Book of European Butterflies we establish the species–area relationship (S = 8.5 A^0.23) and the endemics–area relationship (S = 0.5 A^0.18) of European butterflies. Applying confidence limits as tools for the identification of hotspot countries we show that in the case of butterflies hotspots of endemism and hotspots of overall species richness do not coincide. We introduce plots of residuals from species–area relationships shifted upwards by the 95% confidence limits of the intercept (α-values) as a new tool for identifying and ranking of hotspots.     

DNA barcode based delineation of freshwater fishes from northern Western Ghats of India,one of the world’s biodiversity hotspots

DNA barcodes analyzed by using relevant techniques provide an imperative approach towards validation of prevailing taxa and putative species. Here, molecular methods were used for assessment of 246 barcodes belonging to 81 fish species from northern Western Ghats of India, using, Barcode gap analysis, barcode index number, automatic barcode gap discovery, Poisson tree processes and general mixed Yule-coalescent, these methods had their potential to discriminate 97.53%, 93.90% 95.06%, 93.82% and 92.59% of species respectively. But, some of them tended to estimate the inconsistent number of species leading to discrepancies between the morphological concept and inference from molecular phylogenetic reconstructions. So, we took a standard approach to recognize those methods that produced consistent results, three of five such methods were identified that revealed three hidden cryptic species complexes in Monopterus indicus, Parambassis ranga and Systomus sarana. Further, to validate these three genetically diverged species, we used diagnostic character based approach along with nine unidentified species through BLOG and WEKAs SMO classifier. Those methods were unable to identify these species, which might be due to the limited number of specimens used for the analysis. This is the first effort to generate the DNA barcode reference library of freshwater fishes from northern Western Ghats of India, one of the world’s biodiversity hotspots. These barcodes when analyzed through the defined workflow, will provide valuable measures to prove the efficiency of molecular species delimitation methods in taxonomic discrimination which aid conservation of biodiversity.     

Subterranean “oasis” in the Brazilian semiarid region: neglected sources of biodiversity

Biodiversity and Conservation - Semiarid regions experience conspicuous seasonal variations, especially related to precipitation. Caves in these areas can be exceptions since they are less affected...     

Ant biodiversity and its environmental predictors in the North Kimberley region of Australia’s seasonal tropics

Northern Australia supports the world’s largest estate of undeveloped tropical savannas, but previous studies of ant diversity in the region have covered only a fraction of its land area and habitat diversity. We assess patterns of ant species and functional diversity, their environmental predictors, and biogeographic significance in the central North Kimberley region of Australia’s seasonal tropics. Pitfall traps were used to sample ants at 69 plots in representative savanna habitats, collecting a total of 158 species from 30 genera. Total richness was estimated to be as high as 237 species. At least 29 species across 12 genera appear to have been collected for the first time. Only a single invasive ant was recorded from the study area. Based on cluster analysis we identified six compositionally distinct ant communities, each associated with a combination of vegetation type and underlying geology. Species richness and functional diversity was highest in savanna woodlands and grasslands on sandstone-derived soils, with increasing richness also predicted by a lower mean daily temperature range, a more complex understorey, and lower precipitation seasonality. The abundance of nearly all commonly trapped species was related to temperature, moisture, and habitat variables, although these relationships were highly idiosyncratic. Nearly 40 % of the collected species are known only from the North Kimberley region. The high level of endemism, together with the lack of introduced ant species, identifies the North Kimberley ant fauna as having outstanding biodiversity value. Our identification of ant community types based on mappable soil and vegetation units provides a basis for predicting ant distribution throughout the broader region, and therefore contributing to regional conservation planning and management.     

Going with the flow: a brief history of the study of the honeybee’s navigational ‘odometer’

Honeybees navigate to a food source using a sky-based compass to determine their travel direction, and an odometer to register how far they have travelled. The past 20 years have seen a renewed interest in understanding the nature of the odometer. Early work, pioneered by von Frisch and colleagues, hypothesized that travel distance is measured in terms of the energy that is consumed during the journey. More recent studies suggest that visual cues play a role as well. Specifically, bees appear to gauge travel distance by sensing the extent to which the image of the environment moves in the eye during the journey from the hive to the food source. Most of the evidence indicates that travel distance is measured during the outbound journey. Accumulation of odometric errors is restricted by resetting the odometer every time a prominent landmark is passed. When making detours around large obstacles, the odometer registers the total distance of the path that is flown to the destination, and not the “bee-line” distance. Finally, recent studies are revealing that bees can perform odometry in three dimensions.     

Future eating and country keeping: what role has environmental history in the management of biodiversity?

In order to understand and moderate the effects of the accelerating rate of global environmental change land managers and ecologists must not only think beyond their local environment but also put their problems into a historical context. It is intuitively obvious that historians should be natural allies of ecologists and land managers as they struggle to maintain biodiversity and landscape health. Indeed, ‘environmental history’ is an emerging field where the previously disparate intellectual traditions of ecology and history intersect to create a new and fundamentally interdisciplinary field of inquiry. Environmental history is rapidly becoming an important field displacing many older environmentally focused academic disciplines as well as capturing the public imagination. By drawing on Australian experience I explore the role of ‘environmental history’ in managing biodiversity. First I consider some of the similarities and differences of the ecological and historical approaches to the history of the environment. Then I review two central questions in Australian environment history: landscape‐scale changes in woody vegetation cover since European settlement and the extinction of the marsupials in both historical and pre‐historical time. These case studies demonstrate that environmental historians can reach conflicting interpretations despite using essentially the same data. The popular success of some environmental histories hinges on the fact that they narrate a compelling story concerning human relationships and human value judgements about landscape change. Ecologists must learn to harness the power of environmental history narratives to bolster land management practices designed to conserve biological heritage. They can do this by using various currently popular environmental histories as a point of departure for future research, for instance by testing the veracity of competing interpretations of landscape‐scale change in woody vegetation cover. They also need to learn how to write parables that communicate their research findings to land managers and the general public. However, no matter how sociologically or psychologically satisfying a particular environmental historical narrative might be, it must be willing to be superseded with new stories that incorporate the latest research discoveries and that reflects changing social values of nature. It is contrary to a rational and publicly acceptable approach to land management to read a particular story as revealing the absolute truth.     

Hong Kong’s rich marine biodiversity: the unseen wealth of South China’s megalopolis

Hong Kong is famous as a bustling harbour and financial centre, with a dense burgeoning population impacting its coastal environment. Yet, away from the skyscrapers and the pressures of anthropogenic influence, Hong Kong supports a rich marine biodiversity, including corals and mangrove communities. Despite having a small marine area (1651 km²), a total of 5943 marine species have been recorded in Hong Kong waters. Most of these species were reported during the 1980s and 1990s, but new species continue to be discovered, and ~6500 species are estimated. Even though Hong Kong’s marine area is only ~0.03 % of that of China, the number of marine species recorded in Hong Kong already accounts for ~26 % of the total recorded in China. Hong Kong also contributes to a considerable amount (>30 %) of the species records for several taxa including amphipods, cephalopods, polychaetes and fish in the South China Sea, and ~29 % of the hermit crab species in the largest global marine species database, the World Register of Marine Species. These findings demonstrate the rich marine biota found in Hong Kong, which probably reflects Hong Kong’s location within the fringes of the world’s marine biodiversity hotspot.     

Polymorphism in the 3′ untranslated region of the phenylalanine hydroxylase gene detected by enzyme mismatch cleavage: evolution of haplotypes

A polymorphism was identified in 3 untranslated region of the phenylalanine hydroxylase gene using the newly described mutation detection method, enzyme mismatch cleavage. This polymorphism, 1546 G A, was linked to three mutations on several haplotype backgrounds. A group of haplotypes was identified as evolving from the one ancestral haplotype on which this base substitution occurred. The possible Celtic or Viking origin of this polymorphism is discussed.     

From d’Orbigny to the Devonian: some thoughts on the history of the stratotype concept

D’Orbigny’s stratigraphic contributions were enormous, both practical and theoretical. In his practice, d’Orbigny realised the central importance of using fossil faunas to correlate strata across different countries. His ‘succession chronologique des âges du monde’ (of 1852) recognised 5 periods and 27 stages (ignoring his ‘époque actuelle’). The great majority of the latter were from two Periods, Jurassic (stages 7 to 16) or Cretaceous (17 to 23). D’Orbigny described the palaeontological characteristics, and geographical extensions, of each. Some stages he based on countries he never visited and although he never specified ‘stratotype’ localities, he referred to some as ‘étalon’, ‘le mieux’ or ‘le plus beau’. These leads proved crucial when, in the mid 20th century, stratigraphers realised that definitions of chrono-stratal units must be attempted. The first attempts at typification simply followed zoology, where a type specimen tries to define a central position within the morphological variation of a species. In 1962, an early attempt was made to define Jurassic stages by three type horizons at different type localities (or stratotypes as they were now called) for each. A central horizon was chosen as ‘lectotype section’ and upper and lower boundaries for each were defined elsewhere. In France, it was preferred to investigate original intentions at named localities, through unit-stratotypes. These allowed some nationalistic pride, since France was the home of so many d’Orbignyan stages. 1980 saw the publication Les Étages français et leurs Stratotypes. However, British Silurian stratigraphers had realised that such zoologically based concepts would produce conflict, when any defined upper boundary stratotype conflicted with the defined lower boundary of a superjacent unit. They suggested, from 1962, to define only lower boundaries, via ‘golden spikes’, at basal-boundary stratotypes. This was the method chosen for the basal Devonian stratotype at Klonk, Czech Republic, defined in 1972, and a method adopted globally from 1986. However, this was when correlations were still largely based on fossils. The explosion of so many other stratigraphies since, based on magnetic or chemical records, events etc, has produced a first reaction against the idea that such stratotypes should be so defined, while a second, potentially more major claim, is that any ‘golden spike’ concept may no longer ‘glitter’, as competing stratotype concepts may be holding back stratigraphic progress.     

BioBanking: an environmental scientist’s view of the role of biodiversity banking offsets in conservation

Offsets, first formalised in the United States of America in the 1970s for wetland mitigation, are now widely used globally with the aim to mitigate loss of biodiversity due to development. Embracing biodiversity offsets is one method of governments to meet their commitments under the Millennium Development Goals and the Convention on Biological Diversity. Resource extraction companies see them as a method of gaining access to land, while the community may perceive them as a way of enhancing environmental outcomes. In New South Wales, Australia, BioBanking legislation was introduced in late 2006 with the aim of ‘no net loss’ of biodiversity associated with development, particularly expanding urban and coastal development. The strengths of the legislation are that it aims to enhance threatened species conservation, and raise the profile of conservation of threatened species and habitats. Weaknesses include (1) the narrowness of the definition of biodiversity; (2) the concepts are based on a flawed logic and immature, imprecise and complex science which results in difficulties in determining biodiversity values; (3) likely problems with management and compliance; and (4) an overall lack of resources for implementation and long-term monitoring. It is concluded that the legislation is a concerted effort to deal with biodiversity loss, however, stakeholders have concerns with the process, and it is unworkable with the complexity of such ecosystems (compared for example to carbon credit trading), and underdeveloped disciplines such as restoration biology and ecology. Despite these criticisms, there is a need for all stakeholders to work to improve the outcomes.     

Berriasian ammonites of supposed Tethyan origin from the type ‘Ryazanian’, Russia: a systematic re-interpretation

For more than a century, a number of ammonite taxa of supposed Tethyan origin or affinity have been reported from the Berriasian condensed deposits of Russia (referred to as ‘Ryazanian’). These occurrences have been used to constrain long-distance correlation and palaeobiogeographic interpretation of the Russian Platform during the earliest Cretaceous. We revise these taxa herein. To accommodate the systematic issues, we introduce a new ammonite genus: Mittaites n. gen. (type species: Mazenoticeras ceccai). We also provide re-assessment for the genera Tauricoceras (= Subriasanites), Riasanella, Riasanites, Prorjasanites, and Karasyazites. Considering the strong affinities between these genera (except for Karasyazites), resctricted palaeobiogeographic distribution and a problematic phyletic origin, we erect a new family Riasanitidae n. fam. Our re-examination suggests that the occurrence of western Tethyan migrants in the type ‘Ryazanian’ should be ruled out. Pending new investigation, correlation of the ammonites of the type ‘Ryazanian’ beds with the Berriasian part of the Standard Mediterranean Ammonite Scale (SMAS) should be treated with caution.     

Nomadic behaviour and colony fission in a cooperative spider: life history evolution at the level of the colony?

The concept of colony-level life history evolution is introduced for the cooperative spiders by describing the life cycle and demography of Atbuhna binotata (Araneae: Dictynidae), a species living in groups containing up to several dozen adult females plus their offspring. In a life cycle remarkably similar to that of army ants, the colonies of A binotata were found to reproduce by fission and to alternate nomadic and sedentary phases in tight association with their internal demography. Colonies of other cooperative spiders, on the other hand, remain stationary as they grow for a number of generations before producing propagules that are relatively small subsets of the maternal colony. It is suggested that A. binotata!% peculiar life cycle may have unfolded as a consequence of the two-dimensional architecture of its nests. Expanding two-dimensional nests may fragment more easily than the three-dimensional nests characteristic of other species. A long distance group migration or nomadic phase, described here for the first time for a spider, may have followed as a mechanism to cope with potential disadvantages of fission while selecting for strict synchronization of individual life cycle stages within the nests. It is shown, however, that, as in other cooperative spiders, A. binotatd% sex ratio is also highly female biased. The theoretical implications of biased sex ratios in a species with fissioning colonies are briefly discussed.     

Students’ conceptions of the carbon cycle: identifying and interrelating components of the carbon cycle and tracing carbon atoms across the levels of biological organisation

This study investigates students’ conceptions of the carbon cycle with regard to the components they believe to be relevant to the carbon cycle, how they interrelate these components, the ways in which they trace carbon atoms, and the different levels of biological organisation they consider when doing so. A total of 142 students aged 13–16 years (grades 8–10) participated in the study. A total of 130 students completed the diagnostic task, and an additional 12 students completed both the diagnostic task and were interviewed. The primary results show that the students identified few components of the carbon cycle, tended to trace carbon atoms exclusively at the level of the organism, and had difficulties identifying organic carbon compounds, especially during processes in which carbon compounds are transformed. Considering the main educational implications, we recommend using an instructional strategy that traces carbon atoms across the different levels of biological organisation whilst connecting fragmented knowledge by integrating knowledge from physiology, biochemistry and ecology when teaching the carbon cycle.     

Differentiating the evolution of female song and male–female duets in the New World blackbirds: Can tropical natural history traits explain duet evolution?

Female bird song and combined vocal duets of mated pairs are both frequently associated with tropical, monogamous, sedentary natural histories. Little is known, however, about what selects for duetting behavior versus female song. Female song likely preceded duet evolution and could drive apparent relationships between duets and these natural histories. We compared the evolution of female song and male–female duets in the New World blackbirds (Icteridae) by investigating patterns of gains and losses of both traits and their relationships with breeding latitude, mating system, nesting pattern, and migratory behavior. We found that duets evolved only in lineages in which female song was likely ancestral. Both female song and duets were correlated with tropical breeding, social monogamy, territorial nesting, and sedentary behavior when all taxa were included; however, correlations between duets and these natural history traits disappeared when comparisons were limited to taxa with female song. Also, likelihood values supported stronger relationships between the natural history traits and female song than between these traits and duets. Our results suggest that the natural histories thought to favor the evolution of duetting may in fact be associated with female song and that additional selection pressures are responsible for the evolution of duets.     

Okasha’s evolution and the levels of selection: toward a broader conception of theoretical biology

The debate about the levels of selection has been one of the most controversial both in evolutionary biology and in philosophy of science. Okasha’s book makes the sort of contribution that simply will not be able to be ignored by anyone interested in this field for many years to come. However, my interest here is in highlighting some examples of how Okasha goes about discussing his material to suggest that his book is part of an increasingly interesting trend that sees scientists and philosophers coming together to build a broadened concept of “theory” through a combination of standard mathematical treatments and conceptual analyses. Given the often contentious history of the relationship between philosophy and science, such trend cannot but be welcome.