Social Knowledge and Signals in Primates

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98165/1/ajp22103.pd

Simulated evolution of mating signal diversification in a primate radiation

Divergence in allopatry and subsequent diversification of mating signals on secondary contact (reinforcement) is a major driver of phenotypic diversity. Observing this evolutionary process directly is often impossible, but simulated evolution can pinpoint key drivers of phenotypic variation. We developed evolutionary simulations in which mating signals, modelled as points in phenotype space, evolve across time under varying evolutionary scenarios. We model mate recognition signals in guenons, a primate radiation exhibiting colourful and diverse face patterns hypothesized to maintain reproductive isolation via mate choice. We simulate face pattern evolution across periods of allopatry and sympatry, identifying the role of key parameters in driving evolutionary endpoints. Results show that diversification in allopatry and assortative mate choice on secondary contact can induce rapid phenotypic diversification, resulting in distinctive (between species) and stereotyped (within species) face patterns, similar to extant guenons. Strong selection against hybrids is key to diversification, with even low levels of hybrid fitness often resulting in merged populations on secondary contact. Our results support a key role for reinforcement by assortative mating in the maintenance of species diversity and support the long-proposed prehistorical scenario for how such striking diversity was produced and maintained in perhaps the most colourful of all mammalian clades

Late Holocene uplift of Rhodes, Greece: evidence for a large tsunamigenic earthquake and the implications for the tectonics of the eastern Hellenic Trench System

Several large earthquakes in the Hellenic subduction zone have been documented in historical records from around the eastern Mediterranean, but the relative seismic quiescence of the region over the period of instrumental observation means that the exact locations of these earthquakes and their tectonic significance are not known. We present AMS radiocarbon dates from uplifted late Holocene palaeoshorelines from the island of Rhodes, showing that uplift is most consistent with a single large (MW ≥ 7:7) reverse-faulting earthquake between about 2000 BC and 200 BC. Analysis of the uplift treating the earthquake as a dislocation in an elastic half space shows a predominantly a reverse-faulting event with a slip vector oblique to the direction of convergence between Rhodes and Nubia. We suggest that the fault responsible for the uplift dips at an angle of 30-60° above the more gently-dipping oblique subduction interface. The highly oblique convergence across the eastern Hellenic plate boundary zone appears to be partitioned into reverse slip on faults that strike parallel to the boundary and strike-parallel or oblique slip on the subduction interface. Hydrodynamical simulation of tsunami propagation from a range of tectonically plausible sources suggests that earthquakes on the fault uplifting Rhodes represent a significant tsunami hazard for Rhodes and SW Turkey, and also possibly for Cyprus and the Nile Delta.AH is supported by a Shell Studentship. This study forms part of the NERC- and ESRC-funded project "Earthquakes Without Frontiers".This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/gji/ggv30

Does carbon pricing reduce air travel? Evidence from the Australian 'Clean Energy Future' policy, July 2012 to June 2014

Aviation emissions are an important contributor to global climatic change. As growth in travel demand continues to outstrip improvements in the fuel efficiency of air travel, the aviation contribution to climate change is likely to grow substantially. Consequently, measures that effectively reduce travel demand are required if atmospheric carbon concentrations are to be limited. The efficacy of the Australian Clean Energy Future policy which placed a $23.00AUD (FY 2012) to$24.15 AUD (FY 2013) per tonne levy on carbon-dioxide equivalent emissions from July 2012 to June 2014 is tested. Specifically, time-series regression is used to estimate the effect of this carbon price policy on the level of domestic passenger kilometres flown in Australia, while adjusting for costs of production (i.e. fuel and labour costs), economic activity (i.e. gross domestic product), competitive effects (i.e. airline capacity), and exogenous shocks. There was no evidence that the carbon price reduced the level of domestic aviation in Australia. Carbon pricing measures may have to be levied at a greater rate to affect behavioural change, particularly given the limited potential for future aviation efficiency gains.The authors are grateful to Paul Peeters, NHTV Breda University of Applied Sciences, for his suggestion of several relevant papers

Late Holocene uplift of Rhodes, Greece: evidence for a large tsunamigenic earthquake and the implications for the tectonics of the eastern Hellenic Trench System

Several large earthquakes in the Hellenic subduction zone have been documented in historical records from around the eastern Mediterranean, but the relative seismic quiescence of the region over the period of instrumental observation means that the exact locations of these earthquakes and their tectonic significance are not known. We present AMS radiocarbon dates from uplifted late Holocene palæoshorelines from the island of Rhodes, showing that uplift is most consistent with a single large (MW ≥ 7.7) reverse-faulting earthquake between about 2000 BC and 200 BC. Analysis of the uplift treating the earthquake as a dislocation in an elastic half-space shows a predominantly reverse-faulting event with a slip vector oblique to the direction of convergence between Rhodes and Nubia. We suggest that the fault responsible for the uplift dips at an angle of 30–60° above the more gently dipping oblique subduction interface. The highly oblique convergence across the eastern Hellenic plate boundary zone appears to be partitioned into reverse slip on faults that strike parallel to the boundary and strike-parallel or oblique slip on the subduction interface. Hydrodynamical simulation of tsunami propagation from a range of tectonically plausible sources suggests that earthquakes on the fault uplifting Rhodes represent a significant tsunami hazard for Rhodes and SW Turkey, and also possibly for Cyprus and the Nile Delta