Molecular palaeontology illuminates the evolution of ecdysozoan vision
Colour vision is known to have arisen only twice—once in Vertebrata and once within the Ecdysozoa, in Arthropoda. However, the evolutionary history of ecdysozoan vision is unclear. At the molecular level, visual pigments, composed of a chromophore and a protein belonging to the opsin family, have different spectral sensitivities and these mediate colour vision. At the morphological level, ecdysozoan vision is conveyed by eyes of variable levels of complexity; from the simple ocelli observed in the velvet worms (phylum Onychophora) to the marvellously complex eyes of insects, spiders, and crustaceans. Here, we explore...
Source: Proceedings of the Royal Society B: Biological Sciences - December 5, 2018 Category: Biology Authors: Fleming, J. F., Kristensen, R. M., Sorensen, M. V., Park, T.-Y. S., Arakawa, K., Blaxter, M., Rebecchi, L., Guidetti, R., Williams, T. A., Roberts, N. W., Vinther, J., Pisani, D. Tags: palaeontology, bioinformatics, evolution Palaeobiology Source Type: research

Actuarial senescence in a dimorphic bird: different rates of ageing in morphs with discrete reproductive strategies
It is often hypothesized that intra-sexual competition accelerates actuarial senescence, or the increase in mortality rates with age. However, an alternative hypothesis is that parental investment is more important to determining senescence rates. We used a unique model system, the white-throated sparrow (Zonotrichia albicollis), to study variation in actuarial senescence. In this species, genetically determined morphs display discrete mating strategies and disassortative pairing, providing an excellent opportunity to test the predictions of the above hypotheses. Compared to tan-striped males, white-striped males are more ...
Source: Proceedings of the Royal Society B: Biological Sciences - December 5, 2018 Category: Biology Authors: Grunst, M. L., Grunst, A. S., Formica, V. A., Korody, M. L., Betuel, A. M., Barcelo-Serra, M., Gonser, R. A., Tuttle, E. M. Tags: behaviour, ecology, evolution Source Type: research

Mining and biodiversity: key issues and research needs in conservation science
Mining poses serious and highly specific threats to biodiversity. However, mining can also be a means for financing alternative livelihood paths that, over the long-term, may prevent biodiversity loss. Complex and controversial issues associated with mining and biodiversity conservation are often simplified within a narrow frame oriented towards the negative impacts of mining at the site of extraction, rather than posed as a series of challenges for the conservation science community to embrace. Here, we synthesize core issues that, if better understood, may ensure coexistence between mining and conservation agendas. We il...
Source: Proceedings of the Royal Society B: Biological Sciences - December 5, 2018 Category: Biology Authors: Sonter, L. J., Ali, S. H., Watson, J. E. M. Tags: environmental science Global change and conservation Source Type: research

Age-related response to an acute innate immune challenge in mice: proteomics reveals a telomere maintenance-related cost
Ageing is characterized by the impairment of the acute innate immune response and the upregulation of low-grade inflammation, i.e. inflammaging. At the cellular level, telomeres are considered as a marker of biological ageing as their length is progressively eroded in the absence of repair mechanisms. However, the link between telomeres and inflammaging remains underexplored. We aimed to identify proteins that are differentially expressed between age classes in response to an acute inflammatory challenge. We challenged young (two months) and old (12 months) C57BL/6 mice using bacterial lipopolysaccharide (LPS) and measured...
Source: Proceedings of the Royal Society B: Biological Sciences - December 5, 2018 Category: Biology Authors: Criscuolo, F., Sorci, G., Behaim-Delarbre, M., Zahn, S., Faivre, B., Bertile, F. Tags: molecular biology, immunology, evolution Source Type: research

The achaete-scute complex contains a single gene that controls bristle development in the semi-aquatic bugs
The semi-aquatic bugs (Heteroptera, Gerromorpha) conquered water surfaces worldwide and diversified to occupy puddles, ponds, streams, lakes, mangroves and even oceans. Critical to this lifestyle is the evolution of sets of hairs that allow these insects to maintain their body weight on the water surface and protect the animals against wetting and drowning. In addition, the legs of these insects are equipped with various grooming combs that are important for cleaning and tidying the hair layers for optimal functional efficiency. Here we show that the hairs covering the legs of water striders represent innervated bristles. ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Finet, C., Decaras, A., Armisen, D., Khila, A. Tags: molecular biology, developmental biology, evolution Source Type: research

Partner switching and metabolic flux in a model cnidarian-dinoflagellate symbiosis
Metabolite exchange is fundamental to the viability of the cnidarian–Symbiodiniaceae symbiosis and survival of coral reefs. Coral holobiont tolerance to environmental change might be achieved through changes in Symbiodiniaceae species composition, but differences in the metabolites supplied by different Symbiodiniaceae species could influence holobiont fitness. Using 13C stable-isotope labelling coupled to gas chromatography–mass spectrometry, we characterized newly fixed carbon fate in the model cnidarian Exaiptasia pallida (Aiptasia) when experimentally colonized with either native Breviolum minutum or non-na...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Matthews, J. L., Oakley, C. A., Lutz, A., Hillyer, K. E., Roessner, U., Grossman, A. R., Weis, V. M., Davy, S. K. Tags: biochemistry, physiology, cellular biology Ecology Source Type: research

The rise and fall of dialects in northern elephant seals
Vocal dialects are fundamental to our understanding of the transmission of social behaviours between individuals and populations, however few accounts trace this phenomenon among mammals over time. Northern elephant seals (Mirounga angustirostris) provide a rare opportunity to examine the trajectory of dialects in a long-lived mammalian species. Dialects were first documented in the temporal patterns of the stereotyped vocal displays produced by breeding males at four sites in the North Pacific in 1968 and 1969, as the population recovered from extreme exploitation. We evaluated the longevity of these geographical differen...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Casey, C., Reichmuth, C., Costa, D. P., Le Boeuf, B. Tags: behaviour, evolution Source Type: research

Social living simultaneously increases infection risk and decreases the cost of infection
In this study, we used an anthelmintic treatment experiment in wild Grant's gazelles (Nanger granti), who are commonly infected with gastrointestinal nematodes (GIN), to show that social living confers both costs and benefits related to GIN parasitism. We show that although larger group size increases GIN infection risk, a key cost of GIN infection—the suppression of food intake—is simultaneously moderated by living in larger groups. Our findings help illuminate the complex role parasites play in the evolution of host social behaviour. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Ezenwa, V. O., Worsley-Tonks, K. E. L. Tags: behaviour, health and disease and epidemiology Source Type: research

Enzymatic antioxidants but not baseline glucocorticoids mediate the reproduction-survival trade-off in a wild bird
The trade-off between reproductive investment and survival is central to life-history theory, but the relative importance and the complex interactions among the physiological mechanisms mediating it are still debated. Here we experimentally tested whether baseline glucocorticoid hormones, the redox system or their interaction mediate reproductive investment–survival trade-offs in wild great tits (Parus major). We increased the workload of parental males by clipping three feathers on each wing, and 5 days later determined effects on baseline corticosterone concentrations (Cort), redox state (reactive oxygen metabolite...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Casagrande, S., Hau, M. Tags: behaviour, physiology, evolution Source Type: research

Ageing via perception costs of reproduction magnifies sexual selection
Understanding what factors modulate sexual selection intensity is crucial to a wide variety of evolutionary processes. Recent studies show that perception of sex pheromones can severely impact male mortality when it is not followed by mating (perception costs of reproduction). Here, we examine the idea that this may magnify sexual selection by further decreasing the fitness of males with inherently low mating success, hence increasing the opportunity for sexual selection. We use mathematical modelling to show that even modest mortality perception costs can significantly increase variability in male reproductive success und...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Garcia-Roa, R., Serra, M., Carazo, P. Tags: behaviour, evolution Source Type: research

Fundamental and realized feeding niche breadths of sexual and asexual stick insects
The factors contributing to the maintenance of sex over asexuality in natural populations remain unclear. Ecological divergences between sexual and asexual lineages could help to maintain reproductive polymorphisms, at least transiently, but the consequences of asexuality for the evolution of ecological niches are unknown. Here, we investigated how niche breadths change in transitions from sexual reproduction to asexuality. We used host plant ranges as a proxy to compare the realized feeding niche breadths of five independently derived asexual Timema stick insect species and their sexual relatives at both the species and p...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Larose, C., Parker, D. J., Schwander, T. Tags: ecology, evolution Source Type: research

A new family of dissimilarity metrics for discrete character matrices that include inapplicable characters and its importance for disparity studies
The use of discrete character data for disparity analyses has become more popular, partially due to the recognition that character data describe variation at large taxonomic scales, as well as the increasing availability of both character matrices co-opted from phylogenetic analysis and software tools. As taxonomic scope increases, the need to describe variation leads to some characters that may describe traits not found across all the taxa. In such situations, it is common practice to treat inapplicable characters as missing data when calculating dissimilarity matrices for disparity studies. For commonly used dissimilarit...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Hopkins, M. J., St John, K. Tags: palaeontology, taxonomy and systematics, evolution Source Type: research

Top carnivore decline has cascading effects on scavengers and carrion persistence
Top carnivores have suffered widespread global declines, with well-documented effects on mesopredators and herbivores. We know less about how carnivores affect ecosystems through scavenging. Tasmania's top carnivore, the Tasmanian devil (Sarcophilus harrisii), has suffered severe disease-induced population declines, providing a natural experiment on the role of scavenging in structuring communities. Using remote cameras and experimentally placed carcasses, we show that mesopredators consume more carrion in areas where devils have declined. Carcass consumption by the two native mesopredators was best predicted by competitio...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Cunningham, C. X., Johnson, C. N., Barmuta, L. A., Hollings, T., Woehler, E. J., Jones, M. E. Tags: ecology Source Type: research

Interactions between the sexual identity of the nervous system and the social environment mediate lifespan in Drosophila melanogaster
Sex differences in lifespan are ubiquitous, but the underlying causal factors remain poorly understood. Inter- and intrasexual social interactions are well known to influence lifespan in many taxa, but it has proved challenging to separate the role of sex-specific behaviours from wider physiological differences between the sexes. To address this problem, we genetically manipulated the sexual identity of the nervous system—and hence sexual behaviour—in Drosophila melanogaster, and measured lifespan under varying social conditions. Consistent with previous studies, masculinization of the nervous system in females...
Source: Proceedings of the Royal Society B: Biological Sciences - November 28, 2018 Category: Biology Authors: Flintham, E. O., Yoshida, T., Smith, S., Pavlou, H. J., Goodwin, S. F., Carazo, P., Wigby, S. Tags: behaviour, genetics, evolution Source Type: research

Correction to 'Variation in individual temperature preferences, not behavioural fever, affects susceptibility to chytridiomycosis in amphibians
(Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Sauer, E. L., Fuller, R. C., Richards-Zawacki, C. L., Sonn, J., Sperry, J. H., Rohr, J. R. Tags: ecology Corrections Source Type: research

The influence of cactus spine surface structure on puncture performance and anchoring ability is tuned for ecology
Spines are common morphological features found in almost all major biological groups offering an opportunity to explore large-scale evolutionary convergence across disparate clades. As an example, opuntioid cacti have spines with barbed ornamentation that is remarkably similar in form and scale to that found on porcupine quills, suggesting specific biomechanical convergence across the animal and plant kingdoms. While the mechanics of porcupine quills as defensive mechanisms has been previously tested, the mechanics of cactus spines (which have evolved to fill a number of functions including defence, climbing and dispersal)...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Crofts, S. B., Anderson, P. S. L. Tags: plant science, biomechanics, ecology Morphology and biomechanics Source Type: research

Sex bias in ability to cope with cancer: Tasmanian devils and facial tumour disease
Knowledge of the ecological dynamics between hosts and pathogens during the initial stages of disease emergence is crucial to understanding the potential for evolution of new interspecific interactions. Tasmanian devil (Sarcophilus harrisii) populations have declined precipitously owing to infection by a transmissible cancer (devil facial tumour disease, DFTD) that emerged approximately 20 years ago. Since the emergence of DFTD, and as the disease spreads across Tasmania, the number of devils has dropped up to 90% across 80% of the species's distributional range. As a result, the disease is expected to act as a strong sele...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Ruiz-Aravena, M., Jones, M. E., Carver, S., Estay, S., Espejo, C., Storfer, A., Hamede, R. K. Tags: physiology, ecology, evolution Source Type: research

Frogs adapt to physiologically costly anthropogenic noise
Human activities impose novel pressures on amphibians, which are experiencing unprecedented global declines, yet population-level responses are poorly understood. A growing body of literature has revealed that noise is an anthropogenic stressor that impacts ecological processes spanning subcellular to ecosystem levels. These consequences can impose novel selective pressures on populations, yet whether populations can adapt to noise is unknown. We tested for adaptation to traffic noise, a widespread sensory ‘pollutant’. We collected eggs of wood frogs (Rana sylvatica) from populations from different traffic nois...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Tennessen, J. B., Parks, S. E., Swierk, L., Reinert, L. K., Holden, W. M., Rollins-Smith, L. A., Walsh, K. A., Langkilde, T. Tags: physiology, ecology Global change and conservation Source Type: research

Cultural revolutions reduce complexity in the songs of humpback whales
We examined two measures of song structure, complexity and entropy, in the eastern Australian population over 13 consecutive years. These measures aimed to identify the role of complexity and information content in the vocal learning processes of humpback whales. Complexity was quantified at two hierarchical levels: the entire sequence of individual sound ‘units’ and the stereotyped arrangements of units which comprise a ‘theme’. Complexity increased as songs evolved over time but decreased when revolutions occurred. No correlation between complexity and entropy estimates suggests that changes to co...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Allen, J. A., Garland, E. C., Dunlop, R. A., Noad, M. J. Tags: behaviour, cognition, ecology Source Type: research

The role of citizen science in addressing grand challenges in food and agriculture research
The power of citizen science to contribute to both science and society is gaining increased recognition, particularly in physics and biology. Although there is a long history of public engagement in agriculture and food science, the term ‘citizen science’ has rarely been applied to these efforts. Similarly, in the emerging field of citizen science, most new citizen science projects do not focus on food or agriculture. Here, we convened thought leaders from a broad range of fields related to citizen science, agriculture, and food science to highlight key opportunities for bridging these overlapping yet disconnec...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Ryan, S. F., Adamson, N. L., Aktipis, A., Andersen, L. K., Austin, R., Barnes, L., Beasley, M. R., Bedell, K. D., Briggs, S., Chapman, B., Cooper, C. B., Corn, J. O., Creamer, N. G., Delborne, J. A., Domenico, P., Driscoll, E., Goodwin, J., Hjarding, A., Tags: plant science, ecology, environmental science Review articles Source Type: research

Discovery and exploitation of a natural ecological trap for a mosquito disease vector
Ecological traps occur due to a mismatch between a habitat's attractiveness and quality, wherein organisms show preference for low-quality habitats over other available high-quality habitats. Our previous research identified leaf litter from common blackberry (Rubus allegheniensis) as a natural ecological trap for an important vector for West Nile virus (Culex pipiens), attracting mosquitoes to oviposit in habitats deleterious to the survival of their larvae. Here we demonstrate that manipulation of leaf litter in stormwater catch basins, an important source of disease vector mosquitoes in urban environments, can increase ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Gardner, A. M., Muturi, E. J., Allan, B. F. Tags: ecology Source Type: research

Rethinking dopamine as generalized prediction error
Midbrain dopamine neurons are commonly thought to report a reward prediction error (RPE), as hypothesized by reinforcement learning (RL) theory. While this theory has been highly successful, several lines of evidence suggest that dopamine activity also encodes sensory prediction errors unrelated to reward. Here, we develop a new theory of dopamine function that embraces a broader conceptualization of prediction errors. By signalling errors in both sensory and reward predictions, dopamine supports a form of RL that lies between model-based and model-free algorithms. This account remains consistent with current canon regardi...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Gardner, M. P. H., Schoenbaum, G., Gershman, S. J. Tags: neuroscience, computational biology Neuroscience and cognition Source Type: research

Reproductive control via the threat of eviction in the clown anemonefish
In social groups, high reproductive skew is predicted to arise when the reproductive output of a group is limited, and dominant individuals can suppress subordinate reproductive efforts. Reproductive suppression is often assumed to occur via overt aggression or the threat of eviction. It is unclear, however, whether the threat of eviction alone is sufficient to induce reproductive restraint by subordinates. Here, we test two assumptions of the restraint model of reproductive skew by investigating whether resource limitation generates reproductive competition and whether the threat of eviction leads to reproductive restrain...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Rueger, T., Barbasch, T. A., Wong, M. Y. L., Srinivasan, M., Jones, G. P., Buston, P. M. Tags: behaviour, evolution Source Type: research

Is biasing offspring sex ratio adaptive? A test of Fisher's principle across multiple generations of a wild mammal in a fluctuating environment
Fisher's principle explains that population sex ratio in sexually reproducing organisms is maintained at 1 : 1 owing to negative frequency-dependent selection, such that individuals of the rare sex realize greater reproductive opportunity than individuals of the more common sex until equilibrium is reached. If biasing offspring sex ratio towards the rare sex is adaptive, individuals that do so should have more grandoffspring. In a wild population of North American red squirrels (Tamiasciurus hudsonicus) that experiences fluctuations in resource abundance and population density, we show that overall across 26 years, the sec...
Source: Proceedings of the Royal Society B: Biological Sciences - November 21, 2018 Category: Biology Authors: Wishart, A. E., Williams, C. T., McAdam, A. G., Boutin, S., Dantzer, B., Humphries, M. M., Coltman, D. W., Lane, J. E. Tags: ecology, evolution Source Type: research

Metrics matter: the effect of parasite richness, intensity and prevalence on the evolution of host migration
Parasites have long been thought to influence the evolution of migration, but precisely determining the conditions under which this occurs by quantifying costs of infection remains a challenge. Here we developed a model that demonstrates how the metric used to describe infection (richness/diversity, prevalence or intensity) shapes the prediction of whether migration will evolve. The model shows that predictions based on minimizing richness yield opposite results compared to those based on minimizing prevalence, with migration only selected for when minimizing prevalence. Consistent with these findings, empirical studies th...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Shaw, A. K., Sherman, J., Barker, F. K., Zuk, M. Tags: behaviour, evolution, health and disease and epidemiology Source Type: research

Insights into the roles of CMK-1 and OGT-1 in interstimulus interval-dependent habituation in Caenorhabditis elegans
Habituation is a ubiquitous form of non-associative learning observed as a decrement in responding to repeated stimulation that cannot be explained by sensory adaptation or motor fatigue. One of the defining characteristics of habituation is its sensitivity to the rate at which training stimuli are presented—animals habituate faster in response to more rapid stimulation. The molecular mechanisms underlying this interstimulus interval (ISI)-dependent characteristic of habituation remain unknown. In this article, we use behavioural neurogenetic and bioinformatic analyses in the nematode Caenorhabiditis elegans to ident...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Ardiel, E. L., McDiarmid, T. A., Timbers, T. A., Lee, K. C. Y., Safaei, J., Pelech, S. L., Rankin, C. H. Tags: neuroscience, behaviour, genetics Source Type: research

Adaptation, speciation and extinction in the Anthropocene
Humans have dramatically altered the planet over the course of a century, from the acidity of our oceans to the fragmentation of our landscapes and the temperature of our climate. Species find themselves in novel environments, within communities assembled from never before encountered mixtures of invasives and natives. The speed with which the biotic and abiotic environment of species has changed has already altered the evolutionary trajectory of species, a trend that promises to escalate. In this article, I reflect upon this altered course of evolution. Human activities have reshaped selection pressures, favouring individ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Otto, S. P. Tags: evolution Review articles Source Type: research

Multiple paternity and number of offspring in mammals
Many cooperative social attributes are being linked to characteristics of mating systems, particularly to the rate of multiple paternity that typifies a population. Under the logic that greater offspring production by females should engender greater competition among males to mate with females, it is predicted that multiple paternity should increase with litter sizes. We tested the predicted positive association of multiple paternity and litter size with a meta-analysis of 59 species of mammals. The probability of multiple paternity and mean litter size were positively correlated, but not significantly (Zr = 0.202). Also, ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Dobson, F. S., Abebe, A., Correia, H. E., Kasumo, C., Zinner, B. Tags: behaviour, ecology, evolution Source Type: research

Comparative biogeography: innovations and the rise to dominance of the North Pacific biota
The North Pacific is the largest cold-water source of lineages spreading to other modern marine temperate biotas. How this status was achieved remains unclear. One hypothesis is that functional innovations of large effect, defined as departures from the norm in temperate clades and which confer competitive or defensive benefits, increase resource availability, and raise performance standards in the biota as a whole, evolved earlier and more frequently in the North Pacific than elsewhere in the temperate zone. In support of this hypothesis, phylogenetic and fossil evidence reveals 47 temperate marine innovations beginning i...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Vermeij, G. J. Tags: palaeontology, evolution Palaeobiology Source Type: research

Microbial-tubeworm associations in a 440 million year old hydrothermal vent community
Microorganisms are the chief primary producers within present-day deep-sea hydrothermal vent ecosystems, and play a fundamental role in shaping the ecology of these environments. However, very little is known about the microbes that occurred within, and structured, ancient vent communities. The evolutionary history, diversity and the nature of interactions between ancient vent microorganisms and hydrothermal vent animals are largely undetermined. The oldest known hydrothermal vent community that includes metazoans is preserved within the Ordovician to early Silurian Yaman Kasy massive sulfide deposit, Ural Mountains, Russi...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Georgieva, M. N., Little, C. T. S., Bailey, R. J., Ball, A. D., Glover, A. G. Tags: palaeontology, evolution Palaeobiology Source Type: research

Of molecules, memories and migration: M1 acetylcholine receptors facilitate spatial memory formation and recall during migratory navigation
Many animals use complex cognitive processes, including the formation and recall of memories, for successful navigation. However, the developmental and neurological processes underlying these cognitive aspects of navigation are poorly understood. To address the importance of the formation and recollection of memories during navigation, we pharmacologically manipulated turtles (Chrysemys picta) that navigate long distances using precise, complex paths learned during a juvenile critical period. We treated freely navigating turtles both within and outside of their critical learning period with a specific M1 acetylcholine rece...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Roth, T. C., Krochmal, A. R. Tags: behaviour, cognition Source Type: research

Exploring mechanisms and origins of reduced dispersal in island Komodo dragons
Loss of dispersal typifies island biotas, but the selective processes driving this phenomenon remain contentious. This is because selection via, both indirect (e.g. relaxed selection or island syndromes) and direct (e.g. natural selection or spatial sorting) processes may be involved, and no study has yet convincingly distinguished between these alternatives. Here, we combined observational and experimental analyses of an island lizard, the Komodo dragon (Varanus komodoensis, the world's largest lizard), to provide evidence for the actions of multiple processes that could contribute to island dispersal loss. In the Komodo ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Jessop, T. S., Ariefiandy, A., Purwandana, D., Ciofi, C., Imansyah, J., Benu, Y. J., Fordham, D. A., Forsyth, D. M., Mulder, R. A., Phillips, B. L. Tags: ecology Source Type: research

The hidden cost of sexually selected traits: the metabolic expense of maintaining a sexually selected weapon
Sexually selected weapons are among the most exaggerated traits in nature. Sexual selection theory frequently assumes a high cost of this exaggeration; yet, those costs are rarely measured. We know very little about the energetic resources required to maintain these traits at rest and the difference in energetic costs for the largest individuals relative to the smallest individuals. Knowledge in this area is crucial; resting metabolic rate can account for 30–40% of daily energy expenditure in wild animals. Here, we capitalized on the phenomenon of autotomy to take a unique look at weapon maintenance costs. Using Lept...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Somjee, U., Woods, H. A., Duell, M., Miller, C. W. Tags: behaviour, ecology, evolution Source Type: research

Calcium transfer across the outer mantle epithelium in the Pacific oyster, Crassostrea gigas
The objective of the present study was to characterize the Ca2+ transfer performed by the OME of the Pacific oyster, Crassostrea gigas, as well as to develop an Ussing chamber technique for the functional assessment of transport activities in epithelia of marine bivalves. Kinetic studies revealed that the Ca2+ transfer across the OME consists of one saturable and one linear component, of which the saturable component fits best to Michaelis–Menten kinetics and is characterized by a Km of 6.2 mM and a Vmax of 3.3 nM min–1. The transcellular transfer of Ca2+ accounts for approximately 60% of the total Ca2+ transfe...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Sillanpää, J. K., Sundh, H., Sundell, K. S. Tags: physiology, cellular biology Development and physiology Source Type: research

Real or fake? Natural and artificial social stimuli elicit divergent behavioural and neural responses in mangrove rivulus, Kryptolebias marmoratus
We examined behaviour and neural activity patterns in socially relevant brain nuclei of hermaphroditic mangrove rivulus fish (Kryptolebias marmoratus) provided with different types of social stimuli: stationary model opponent, regular mirror, non-reversing mirror and live opponent. We found that: (i) individuals faced with a regular mirror were less willing to interact with, delivered fewer attacks towards and switched their orientation relative to the opponent more frequently than fish exposed to a non-reversing mirror image or live opponent; (ii) fighting with a regular mirror image caused higher expression of immediate-...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Li, C.-Y., Hofmann, H. A., Harris, M. L., Earley, R. L. Tags: neuroscience, behaviour, cognition Neuroscience and cognition Source Type: research

Early bursts of disparity and the reorganization of character integration
‘Early bursts' of morphological disparity (i.e. diversity of anatomical types) are common in the fossil record. We typically model such bursts as elevated early rates of independent character change. Developmental theory predicts that modules of linked characters can change together, which would mimic the effects of elevated independent rates on disparity. However, correlated change introducing suboptimal states should encourage breakup (parcellation) of character suites allowing new (or primitive) states to evolve until new suites arise (relinkage). Thus, correlated change–breakup–relinkage presents mech...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Wagner, P. J. Tags: palaeontology, developmental biology, evolution Palaeobiology Source Type: research

Experimental disturbances reveal group-level costs of social instability
In group-living species, social stability is an important trait associated with the evolution of complex behaviours such as cooperation. While the drivers of stability in small groups are relatively well studied, little is known about the potential impacts of unstable states on animal societies. Temporary changes in group composition, such as a social group splitting and recombining (i.e. a disturbance event), can result in individuals having to re-establish their social relationships, thus taking time away from other tasks such as foraging or vigilance. Here, we experimentally split socially stable groups of captive zebra...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Maldonado-Chaparro, A. A., Alarcon-Nieto, G., Klarevas-Irby, J. A., Farine, D. R. Tags: behaviour Source Type: research

Carbon limitation of lake productivity
Phytoplankton productivity in lakes controls the rate of synthesis of organic matter that drives energy flow through the food webs and regulates the transparency and oxygen conditions in the water. Limitation of phytoplankton productivity and biomass by nutrients and light availability is an established paradigm for lake ecosystems, whereas invasion of atmospheric CO2 has been assumed to cover the high demands of dissolved inorganic carbon (DIC) during intense organic productivity. We challenge this paradigm, and show up to a 5-fold stimulation of phytoplankton productivity and biomass in outdoor mesocosms enriched with DI...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Kragh, T., Sand-Jensen, K. Tags: ecology, environmental science Source Type: research

Neonatal mice exposed to a high-fat diet in utero influence the behaviour of their nursing dam
In this study, we used a mouse model of high-fat (HF) diet feeding, which has been shown to influence maternal behaviours, combined with cross-fostering to discriminate between these effects. We tested whether the diet of the F0 dam or the exposure experienced by the F1 pups in utero is the most significant predictor of maternal behaviour. Neither factor significantly influenced pup retrieval behaviours. However, strikingly, F1 in utero exposure was a significant predictor of maternal behaviour in the 15 min immediately following pup retrieval while F0 diet had no discernable effect. Our findings suggest that in utero expo...
Source: Proceedings of the Royal Society B: Biological Sciences - November 14, 2018 Category: Biology Authors: Baptissart, M., Lamb, H. E., To, K., Bradish, C., Tehrani, J., Reif, D., Cowley, M. Tags: behaviour, physiology, developmental biology Source Type: research

Prey abundance and urbanization influence the establishment of avian predators in a metropolitan landscape
Urbanization causes the simplification of natural habitats, resulting in animal communities dominated by exotic species with few top predators. In recent years, however, many predators such as hawks, and in the US coyotes and cougars, have become increasingly common in urban environments. Hawks in the Accipiter genus, especially, are recovering from widespread population declines and are increasingly common in urbanizing landscapes. Our goal was to identify factors that determine the occupancy, colonization and persistence of Accipiter hawks in a major metropolitan area. Through a novel combination of citizen science and a...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: McCabe, J. D., Yin, H., Cruz, J., Radeloff, V., Pidgeon, A., Bonter, D. N., Zuckerberg, B. Tags: ecology Source Type: research

A host immune hormone modifies parasite species interactions and epidemics: insights from a field manipulation
This study therefore experimentally links host immune hormones to within-host priority effects and parasite epidemics, advancing a more mechanistic understanding of how interactions among parasites alter their epidemics. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Halliday, F. W., Umbanhowar, J., Mitchell, C. E. Tags: ecology Source Type: research

Acute drivers influence recent inshore Great Barrier Reef dynamics
Understanding the dynamics of habitat-forming organisms is fundamental to managing natural ecosystems. Most studies of coral reef dynamics have focused on clear-water systems though corals inhabit many turbid regions. Here, we illustrate the key drivers of an inshore coral reef ecosystem using 10 years of biological, environmental, and disturbance data. Tropical cyclones, crown-of-thorns starfish, and coral bleaching are recognized as the major drivers of coral loss at mid- and offshore reefs along the Great Barrier Reef (GBR). In comparison, little is known about what drives temporal trends at inshore reefs closer to majo...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Lam, V. Y. Y., Chaloupka, M., Thompson, A., Doropoulos, C., Mumby, P. J. Tags: computational biology, ecology Source Type: research

Intraspecific brain size variation between coexisting sunfish ecotypes
Variation in spatial complexity and foraging requirements between habitats can impose different cognitive demands on animals that may influence brain size. However, the relationship between ecologically related cognitive performance and brain size is not well established. We test whether variation in relative brain size and brain region size is associated with habitat use within a population of pumpkinseed sunfish composed of different ecotypes that inhabit either the structurally complex shoreline littoral habitat or simpler open-water pelagic habitat. Sunfish using the littoral habitat have on average 8.3% larger brains ...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Axelrod, C. J., Laberge, F., Robinson, B. W. Tags: neuroscience, ecology, evolution Neuroscience and cognition Source Type: research

Isogamy in large and complex volvocine algae is consistent with the gamete competition theory of the evolution of anisogamy
Although the gamete competition theory remains the dominant explanation for the evolution of anisogamy, well-known exceptions to its predictions have raised doubts about the completeness of the theory. One of these exceptions is isogamy in large or complex species of green algae. Here, we show that this exception may be explained in a manner consistent with a game-theoretic extension of the original theory: a constraint on the minimum size of a gamete may prevent the evolution of continuously stable anisogamy. We show that in the volvocine algae, both gametes of isogamous species retain an intact chloroplast, whereas the c...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: da Silva, J., Drysdale, V. L. Tags: evolution Source Type: research

An experimental test of the mutation-selection balance model for the maintenance of genetic variance in fitness components
We describe the underlying theory and use it to test the MSB model for three traits in Drosophila melanogaster. We find evidence for differences among traits, with MSB being sufficient to explain genetic variance in larval viability but not male mating success or female fecundity. Our results are consistent with balancing selection on sexual fitness components, and demonstrate the feasibility of rigorous statistical tests of the MSB model. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Sharp, N. P., Agrawal, A. F. Tags: genetics, evolution Source Type: research

Non-stationary climate-salmon relationships in the Gulf of Alaska
Studies of climate effects on ecology often account for non-stationarity in individual physical and biological variables, but rarely allow for non-stationary relationships among variables. Here, we show that non-stationary relationships among physical and biological variables are central to understanding climate effects on salmon (Onchorynchus spp.) in the Gulf of Alaska during 1965–2012. The relative importance of two leading patterns in North Pacific climate, the Pacific Decadal Oscillation (PDO) and North Pacific Gyre Oscillation (NPGO), changed around 1988/1989 as reflected by changing correlations with leading a...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Litzow, M. A., Ciannelli, L., Puerta, P., Wettstein, J. J., Rykaczewski, R. R., Opiekun, M. Tags: ecology, environmental science Source Type: research

Tropical tree diversity mediates foraging and predatory effects of insectivorous birds
Biodiversity affects the structure of ecological communities, but little is known about the interactive effects of diversity across multiple trophic levels. We used a large-scale forest diversity experiment to investigate the effects of tropical tree species richness on insectivorous birds, and the subsequent indirect effect on predation rates by birds. Diverse plots (four tree species) had higher bird abundance (61%), phylogenetic diversity (61%), and functional diversity (55%) than predicted based on single-species monocultures, which corresponded to higher attack rates on artificial caterpillars (65%). Tree diversity ef...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Nell, C. S., Abdala-Roberts, L., Parra-Tabla, V., Mooney, K. A. Tags: ecology Source Type: research

Dental ontogeny in extinct synapsids reveals a complex evolutionary history of the mammalian tooth attachment system
This study shows for the first time that the ligamentous tooth attachment system is not unique to crown mammals within Synapsida, having arisen in several non-mammalian therapsid clades as a result of neoteny and progenesis in dental ontogeny. Mammalian tooth attachment is here re-interpreted as a paedomorphic condition relative to the ancestral synapsid form of tooth attachment. (Source: Proceedings of the Royal Society B: Biological Sciences)
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: LeBlanc, A. R. H., Brink, K. S., Whitney, M. R., Abdala, F., Reisz, R. R. Tags: palaeontology, evolution Palaeobiology Source Type: research

Local meteorological conditions reroute a migration
For migrating animals, realized migration routes and timing emerge from hundreds or thousands of movement decisions made along migration routes. Local weather conditions along migration routes continually influence these decisions, and even relatively small changes in en route weather may cumulatively result in major shifts in migration patterns. Here, we analysed satellite tracking data to score a discrete navigation decision by a large migratory bird as it navigated a high-latitude, 5000 m elevation mountain range to understand how those navigational decisions changed under different weather conditions. We showed that wi...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Eisaguirre, J. M., Booms, T. L., Barger, C. P., McIntyre, C. L., Lewis, S. B., Breed, G. A. Tags: behaviour, ecology, environmental science Source Type: research

Elements of time and place: manganese and barium in shark vertebrae reflect age and upwelling histories
As upper-level predators, sharks are important for maintaining marine food web structure, but populations are threatened by fishery exploitation. Sustainable management of shark populations requires improved understanding of migration patterns and population demographics, which has traditionally been sought through physical and/or electronic tagging studies. The application of natural tags such as elemental variations in mineralized band pairs of elasmobranch vertebrae cartilage could also reveal endogenous and exogenous processes experienced by sharks throughout their life histories. Here, elemental profiles were characte...
Source: Proceedings of the Royal Society B: Biological Sciences - November 7, 2018 Category: Biology Authors: Mohan, J. A., Miller, N. R., Herzka, S. Z., Sosa-Nishizaki, O., Kohin, S., Dewar, H., Kinney, M., Snodgrass, O., Wells, R. J. D. Tags: biochemistry, ecology Source Type: research