Biology

CHURCH NEWS: NEW UNITY MOVEMENT STEPS PROPOSED

by Daniel Keeran MSW

by Daniel Keeran, MSW (distrbute freely without charge)

Against the unity prayer of Jesus in the gospel of John chapter 17, divisions within Christianity have been common... more Against the unity prayer of Jesus in the gospel of John chapter 17, divisions within Christianity have been common from the beginning. New steps for unity are outlined that provide grass-roots opportunities in local churches and communities.

Fundamental to the new unity movement are principles and a change in paradigm that give a fresh approach to the ancient problem of divisions among people who identify themselves as followers of Jesus.

The Successful Fathers Argument for Sex

by Jon Schull

The View from the Adaptive Landscape

by Jon Schull

Engineering love

by Brian Earp

Savulescu, J. and Sandberg, A. (2012). Love machine: Engineering lifelong romance. New Scientist, 2864, 28-29.

Essay partially adapted from Earp, B. D., Sandberg, A., and Savulescu, J. (2012). Natural selection, childrearing, and the ethics of marriage (and divorce): Building a case for the neuroenhancement of human relationships. Philosophy & Technology, forthcoming [see "profile" box in article].

Available at the New Scientist website: http://www.newscientist.com/article/mg21428646.200-love-machine-engineering-lifelong-romance.html

New Scientist BIG IDEA section, May 2012.

With break-up and divorce a major part of modern life, it looks... more New Scientist BIG IDEA section, May 2012.

With break-up and divorce a major part of modern life, it looks like we may be outliving our inborn capacity to love. But there could be a way to outwit evolution and make love last.

Also available at New Scientist: http://www.newscientist.com/article/mg21428646.200-love-machine-engineering-lifelong-romance.html.

Warming alters the metabolic balance of ecosystems

by Gabriel Yvon-Durocher

The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most... more The carbon cycle modulates climate change, via the regulation of atmospheric CO2, and it represents one of the most important services provided by ecosystems. However, considerable uncertainties remain concerning potential feedback between the biota and the climate. In particular, it is unclear how global warming will affect the metabolic balance between the photosynthetic fixation and respiratory release of CO2 at the ecosystem scale. Here, we present a combination of experimental field data from freshwater mesocosms, and theoretical predictions derived from the metabolic theory of ecology to investigate whether warming will alter the capacity of ecosystems to absorb CO2. Our manipulative experiment simulated the temperature increases predicted for the end of the century and revealed that ecosystem respiration increased at a faster rate than primary production, reducing carbon sequestration by 13 per cent. These results confirmed our theoretical predictions based on the differential activation energies of these two processes. Using only the activation energies for whole ecosystem photosynthesis and respiration we provide a theoretical prediction that accurately quantified the precise magnitude of the reduction in carbon sequestration observed experimentally. We suggest the combination of whole-ecosystem manipulative experiments and ecological theory is one of the most promising and fruitful research areas to predict the impacts of climate change on key ecosystem services.

Ecological Networks in a Changing Climate

by Gabriel Yvon-Durocher

Attempts to gauge the biological impacts of climate change have typically
focussed on the lower levels of... more Attempts to gauge the biological impacts of climate change have typically
focussed on the lower levels of organization (individuals to populations), rather than considering more complex multi-species systems, such as entire ecological networks (food webs, mutualistic and host–parasitoid networks).We evaluate the possibility that a few principal drivers underpin network-level responses to climate change, and that these drivers can be studied to develop a more coherent theoretical framework than is currently provided by phenomenological approaches. For instance, warming will elevate individual ectotherm metabolic rates, and direct and indirect effects of changes in atmospheric conditions are expected to alter the stoichiometry of interactions between primary consumers and basal resources; these effects are general and pervasive, and will permeate through the entire networks that they affect. In addition, changes in the density and viscosity of aqueous media could alter interactions among very small organisms and disrupt the pycnoclines that currently compartmentalize many aquatic networks in time and space. We identify a range of approaches and potential model systems that are particularly well suited to network-level studies within the context of climate change. We also highlight potentially fruitful areas of research with a view to improving our predictive power regarding climate change impacts on networks. We focus throughout on mechanistic approaches rooted in first principles that demonstrate potential for application across a wide range of taxa and systems.

Global change and food webs in running waters

by Gabriel Yvon-Durocher

Riverine habitats are vulnerable to a host of environmental stressors, many of which are increasing in frequency and... more Riverine habitats are vulnerable to a host of environmental stressors, many of which are increasing in frequency and intensity across the globe. Climate change is arguably the greatest threat on the horizon, with serious implications for freshwater food webs via alterations in thermal regimes, resource quality and availability, and hydrology. This will induce radical restructuring of many food webs, by altering the identity of nodes, the strength and patterning of interactions and consequently the dynamics and architecture of the trophic network as a whole. Although such effects are likely to be apparent globally, they are predicted to be especially rapid and dramatic in high altitude and latitude ecosystems, which represent ‘sentinel systems’. The complex and subtle connections between members of a food web and potential synergistic interactions with other environmental stressors can lead to seemingly counterintuitive responses to perturbations that cannot be predicted from the traditional focus of studying individual species in isolation. In this review, we highlight the need for developing new network-based approaches to understand and predict the consequences of global change in running waters.

Macroecological patterns and niche structure in a new marine food web

by Gabriel Yvon-Durocher

The integration of detailed information on feeding interactions with measures of abundance and body mass of... more The integration of detailed information on feeding interactions with measures of abundance and body mass of individuals provides a powerful platform for understanding ecosystem organisation. Metabolism and, by proxy, body mass constrain the flux, turnover and storage of energy and biomass in food webs. Here, we present the first food web data for Lough Hyne, a species rich Irish Sea Lough. Through the application of individual- and size-based analysis of the abundance-body mass relationship, we tested predictions derived from the metabolic theory of ecology. We found that individual body mass constrained the flux of biomass and determined its distribution within the food web. Body mass was also an important determinant of diet width and niche overlap, and predator diets were nested hierarchically, such that diet width increased with body mass. We applied a novel measure of predator-prey biomass flux, which revealed that most interactions in Lough Hyne were weak, whereas only a few were strong. Further, the patterning of interaction strength between prey sharing a common predator revealed that strong interactions were nearly always coupled with weak interactions. Our findings illustrate that important insights into the organisation, structure and stability of ecosystems can be achieved through the theoretical exploration of detailed empirical data.

The Temperature Dependence of the Carbon Cycle in Aquatic Ecosystems

by Gabriel Yvon-Durocher

The carbon cycle modulates climate change via the regulation of atmospheric CO2, and represents one of the most... more The carbon cycle modulates climate change via the regulation of atmospheric CO2, and represents one of the most important ecosystem services of value to humans. However, considerable uncertainties remain concerning potential feedbacks between the biota and the climate. We developed theoretical models
derived from the metabolic theory of ecology (MTE), and tested them in an ecosystem-level manipulative experiment in freshwater mesocosms. The yearlong experiment simulated a warming scenario (A1B; [IPCC, 2007]) expected by the end of the century. The key components of the carbon cycle – that is gross primary production (GPP), ecosystem respiration (ER) and CH4 efflux (ME) – measured in our experiment were all strongly related to temperature. Their temperature dependence was typically constrained by the average activation energy of their particular metabolic pathway, and as predicted by our models, this increased progressively for GPP, ER and ME. Warming of 4°C decreased the sequestration of CO2 by 13%, increased the fraction of primary production effluxing as methane by 20% and the fraction of ER as methane by 9%, in line with the offset in their respective activation energies. Because methane has 21 times the greenhouse gas radiative potential of CO2, these results suggest aquatic ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle.

We then used a series of global data compilations of measurements of rates of primary production and respiration to better understand the temperature dependence of the carbon cycle in other aquatic ecosystems and to compare them with data from terrestrial systems. Our experimental results were mirrored by our global data compilations, with the effective activation energy for marine and freshwater primary production identical to GPP measured in our experiment. Similarly, the temperature dependences of respiration in estuaries, lakes and the ocean were indistinguishable from that of ER in our experiment. Finally, our study suggests that the temperature dependence of primary production and respiration in aquatic ecosystems might differ from those in terrestrial ecosystems, and this could be crucial in predicting the future response of the carbon cycle in these different systems to global warming.

Ecological Networks: Information Theory Meets Darwin's Entangled Bank

by Gabriel Yvon-Durocher

Is it possible to untangle the ‘entangled bank’ — Darwin’s metaphor for the complexity and connectedness of species in... more Is it possible to untangle the ‘entangled bank’ — Darwin’s metaphor for the complexity and connectedness of species in the natural world? Studies on webs of species interactions suggest so, but a major question remains unanswered: how specialized are different ecological networks? By considering how strongly species interact with each other, information theory may give the answer.

Warming increases the proportion of primary production emitted as methane from freshwater mesocosms

by Gabriel Yvon-Durocher

Methane (CH4) and carbon dioxide (CO2) are the dominant gaseous end products of the remineralization of organic carbon... more Methane (CH4) and carbon dioxide (CO2) are the dominant gaseous end products of the remineralization of organic carbon and also the two largest contributors to the anthropogenic greenhouse effect. We investigated whether warming altered the balance of CH4 efflux relative to gross primary production (GPP) and ecosystem respiration (ER) in a freshwater mesocosm experiment. Whole ecosystem CH4 efflux was strongly related to temperature with an apparent activation energy of 0.85 eV. Furthermore, CH4 efflux increased faster than ER or GPP with temperature, with all three processes having sequentially lower activation energies. Warming of 4C increased the fraction of GPP effluxing as CH4 by 20% and the fraction of ER as CH4 by 9%, in line with the offset in their respective activation energies. Because CH4 is 21 times more potent as a greenhouse gas, relative to CO2, these results suggest freshwater ecosystems could drive a previously unknown positive feedback between warming and the carbon cycle.

Warming alters the size spectrum and shifts the distribution of biomass in freshwater ecosystems

by Gabriel Yvon-Durocher

Organism size is one of the key determinants of community structure, and its relationship with abundance can describe... more Organism size is one of the key determinants of community structure, and its relationship with abundance can describe how biomass is partitioned among the biota within an ecosystem. An outdoor freshwater mesocosm experiment was used to determine how warming of 4°C would affect the size, biomass and taxonomic structure of planktonic communities. Warming increased the steepness of the community size spectrum by increasing the prevalence of small organisms, primarily within the phytoplankton assemblage and it also reduced the mean and maximum size of phytoplankton by approximately one order of magnitude. The observed shifts in phytoplankton size structure were reflected in changes in phytoplankton community composition, though zooplankton taxonomic composition was unaffected by warming. Furthermore, warming reduced community biomass and total phytoplankton biomass, although zooplankton biomass was unaffected. This resulted in an increase in the zooplankton to phytoplankton biomass ratio in the warmed mesocosms, which could be explained by faster turnover within the phytoplankton assemblages. Overall, warming shifted the distribution of phytoplankton size towards smaller individuals with rapid turnover and low standing biomass, resulting in a reorganization of the biomass structure of the food webs. These results indicate future environmental warming may have profound effects on the structure and functioning of aquatic communities and ecosystems.

Warming alters community size structure and ecosystem functioning

by Gabriel Yvon-Durocher

Global warming can affect all levels of biological complexity, though we currently understand least about its... more Global warming can affect all levels of biological complexity, though we currently understand least about its potential impact on communities and ecosystems. At the ecosystem level, warming has the capacity to alter the structure of communities and the rates of key ecosystem processes they mediate. Here we assessed the effects of a 4C rise in temperature on the size structure and taxonomic composition of benthic communities in aquatic mesocosms, and the rates of detrital decomposition they mediated. Warming had no effect on biodiversity, but altered community size structure in two ways. In spring, warmer systems exhibited steeper size spectra driven by declines in total community biomass and the proportion of large organisms. By contrast, in autumn, warmer systems had shallower size spectra driven by elevated total community biomass and a greater proportion of large organisms. Community-level shifts were mirrored by changes in decomposition rates. Temperature-corrected microbial and macrofaunal decomposition rates reflected the shifts in community structure and were strongly correlated with biomass across mesocosms. Our study demonstrates that the 4C rise in temperature expected by the end of the century has the potential to alter the structure and functioning of aquatic ecosystems profoundly, as well as the intimate linkages between these levels of ecological organization.

Across ecosystem comparisons of size structure: methods, approaches and prospects

by Gabriel Yvon-Durocher

Understanding how ecological communities are structured and how this may vary between different types of ecosystems is... more Understanding how ecological communities are structured and how this may vary between different types of ecosystems is a fundamental question in ecology. We develop a general framework for quantifying size-structure within and among different ecosystem types (e.g. terrestrial, freshwater or marine), via the use of a suite of bivariate relationships between organismal size and properties of individuals, populations, assemblages, pair-wise interactions, and network topology. Each of these relationships can be considered a dimension of size-structure, along which real communities lie on a continuous scale. For example, the strength, slope, or elevation of the body mass-versus-abundance or predator size-versus-prey size relationships may vary systematically among ecosystem types. We draw on examples from the literature and suggest new ways to use allometries for comparing among ecosystem types, which we illustrate by applying them to published data. Finally, we discuss how dimensions of size-structure are interconnected and how we could approach this complex hierarchy systematically. We conclude: (1) there are multiple dimensions of size-structure; (2) communities may be size-structured in some of these dimensions, but not necessarily in others; (3) across-system comparisons via rigorous quantitative statistical methods are possible, and (4) insufficient data are currently available to illuminate thoroughly the full extent and nature of differences in size-structure among ecosystem types.

Consistent temperature dependence of respiration across ecosystems contrasting in thermal history

by Gabriel Yvon-Durocher

Ecosystem respiration is a primary component of the carbon cycle and understanding the mechanisms that determine its... more Ecosystem respiration is a primary component of the carbon cycle and understanding the mechanisms that determine its temperature dependence will be important for predicting how rates of carbon efflux might respond to global warming. We used a rare model system, comprising a network of geothermally heated streams ranging in temperature from 5 °C to 25 °C, to explore the nature of the relationship between respiration and temperature. Using this ‘natural experiment’, we tested whether the natal thermal regime of stream communities influenced the temperature dependence of respiration in the absence of other potentially confounding variables. An empirical survey of 13 streams across the thermal gradient revealed that the temperature dependence of whole-stream respiration was equivalent to the average activation energy of the respiratory complex (0.6–0.7 eV). This observation was also consistent for in-situ benthic respiration. Laboratory experiments, incubating biofilms from four streams across the thermal gradient at a range of temperatures, revealed that the activation energy and Q10 of respiration were remarkably consistent across streams, despite marked differences in their thermal history and significant turnover in species composition. Furthermore, absolute rates of respiration at standardised temperature were also unrelated to ambient stream temperature, but strongly reflected differences in biofilm biomass. Together, our results suggest that the core biochemistry,which drives the kinetics of oxidative respiratory metabolism, may be well conserved among diverse taxa and environments, and that the intrinsic sensitivity of respiration to temperature is not influenced by ambient environmental temperature.

Comparative distribution & diversity of bats in Sarawak, Borneo. 2011

by M.T. Abdullah, PhD

Read other papers by Vijaya et al in this page

Surveys on the chiropteran diversity were conducted at eight different localities in Sarawak to document the bat... more Surveys on the chiropteran diversity were conducted at eight different localities in Sarawak to document the bat diversity as well as to estimate the composition of bats in these areas. The major finding of bat surveys shows that montane areas have distinct chiropteran composition compared with those in lowland and logged areas. Disturbed habitats do pose a threat to the overall diversity of bats, with the generalist bats been more successful in colonising altered area than those with specialised habitat requirements. Sampling of bats targeted at different site and vegetation type from several protected areas in Sarawak have revealed the current record of bats in Sarawak and its diversity can be monitored for better management of biodiversity in this important region.

Keywords: Diversity, chiroptera, forest types, montane, habitat disturbance, Borneo

A morphometric analysis of Rhinolophus species complex. 2008.

by M.T. Abdullah, PhD

DFA and CVA analyses were used to differentiate Malaysian Rhinolophus species complex. DFA and CVA analyses were used to differentiate Malaysian Rhinolophus species complex.

Distribution and status of the Sumatran rhinoceros in Endau Rompin, Malaysia. 1983. Malayan Nature Journal

by M.T. Abdullah, PhD

Diversity of bats at two contrasting elevations in a protected dipterocarp forest Kubah NP. 2008

by M.T. Abdullah, PhD

We present an assessment of the diversity of Bornean bats at two contrasting elevations (119 m and 787 m) in Kubah... more We present an assessment of the diversity of Bornean bats at two contrasting elevations (119 m and 787 m) in Kubah National Park surveyed between August and December 2006. Three hundred and eighty-two individuals of bats from 26 species representing six families were recorded using 20 mist nets and three harp traps. The most commonly caught bat was Hipposideros cervinus (Gould, 1863) (n = 168) followed by Penthetor lucasi (Dobson, 1880) (n = 55), and they were also the most commonly detected species at low and high elevation sites, respectively. This survey yielded the first recorded specimen of Pipistrellus cuprosus Hill and Francis, 1984 for Sarawak. Analysis of daily cumulative capture rates indicated that further effort at these sites may not yield additional species if sampling techniques and locations are maintained. Species diversity index of Megachiroptera was higher at high elevations (H’ = 0.567 versus H’ = 0.466) whereas the species diversity index of Microchiroptera was greatest at low elevations (H’= 0.905 vs H’ = 1.225).

MOHD-AZLAN, J., SITI HASMAH TAHA, CHARLIE J.M. LAMAN & M.T. ABDULLAH.

Phylogenetics of Pteropodinae. 2006

by M.T. Abdullah, PhD