Investigating the palaeoenvironmental context of Late Pleistocene human dispersals into Southeast Asia: a review of stable isotope applications

We review palaeoenvironmental applications of stable isotope analysis to Late Pleistocene archaeological sites across Southeast Asia (SEA), a region critical to understanding the evolution of Homo sapiens and other co-existing Late Pleistocene (124–11.7 ka) hominins. Stable isotope techniques applied to archaeological deposits offer the potential to develop robust palaeoenvironmental reconstructions, to contextualise the occupational and non-occupational history of a site. By evaluating the published research in this field, we show that sediments, guano, tooth enamel, speleothem and biomolecular material such as leaf waxes have great potential to provide site-specific palaeoenvironmental records and local and catchment-scale landscape context to hominin dispersal in the region. However, stable isotope techniques used in these contexts are in their infancy in SEA, and the diagenetic controls associated with hot and humid environments that typify the region are not yet fully understood. Additionally, availability of sources of stable isotopes varies between sites. Nonetheless, even the limited research currently available shows that stable isotope analyses can aid in developing a better understanding of the role of the environment on the nature and timing of dispersals of our species eastwards into SEA and beyond.Meghan S. McAllister, Mike W. Morley, Jonathan J. Tyler, Francesca A. McInerney, Alison J. Blyt

Eukaryote-conserved methylarginine is absent in diplomonads and functionally compensated in Giardia

Methylation is a common posttranslational modification of arginine and lysine in eukaryotic proteins. Methylproteomes are best characterized for higher eukaryotes, where they are functionally expanded and evolved complex regulation. However, this is not the case for protist species evolved from the earliest eukaryotic lineages. Here, we integrated bioinformatic, proteomic, and drug-screening data sets to comprehensively explore the methylproteome of Giardia duodenalis—a deeply branching parasitic protist. We demonstrate that Giardia and related diplomonads lack arginine-methyltransferases and have remodeled conserved RGG/RG motifs targeted by these enzymes. We also provide experimental evidence for methylarginine absence in proteomes of Giardia but readily detect methyllysine. We bioinformatically infer 11 lysine-methyltransferases in Giardia, including highly diverged Su(var)3-9, Enhancer-of-zeste and Trithorax proteins with reduced domain architectures, and novel annotations demonstrating conserved methyllysine regulation of eukaryotic elongation factor 1 alpha. Using massspectrometry, we identify more than 200 methyllysine sites in Giardia, including in species-specific gene families involved in cytoskeletal regulation, enriched in coiled-coil features. Finally, we use known methylation inhibitors to show that methylation plays key roles in replication and cyst formation in this parasite. This study highlights reduced methylation enzymes, sites, and functions early in eukaryote evolution, including absent methylarginine networks in the Diplomonadida. These results challenge the view that arginine methylation is eukaryote conserved and demonstrate that functional compensation of methylarginine was possible preceding expansion and diversification of these key networks in higher eukaryotes.Samantha J. Emery-Corbin, Joshua J. Hamey, Brendan R.E. Ansell, Balu Balan, Swapnil Tichkule, Andreas J. Stroehlein, Crystal Cooper, Bernie V. McInerney, Soroor Hediyeh-Zadeh, Daniel Vuong, Andrew Crombie, Ernest Lacey, Melissa J. Davis, Marc R. Wilkins, Melanie Bahlo, Staffan G. Svärd, Robin B. Gasser, and Aaron R. Je

Reconstructing the environmental conditions experienced by early modern humans at Tam Pà Ling (northeast Laos) using higher plant wax biomarkers

International audienc

A Constructivist Approach to Climate Change Teaching and Learning

Copyright © 1999-2009 John Wiley & Sons, Inc. Journal compilation © 2009 Institute of Australian GeographersIt is now broadly acknowledged that climate change due to an enhanced Greenhouse Effect is underway and such change will have major implications for our societies and environments. This paper outlines a pedagogical approach devised to encourage learning and critical thinking about climate change. A constructivist approach to teaching and learning is applied to stimulate analysis of potential impacts of climate change on systems familiar to secondary school students in South Australia. The problem-based method guides students through a conceptualisation of the implications of environmental change. Students at Woodcroft College, when given the opportunity to examine the potential climate change impacts on a local coastal ecosystem, found the method to be both challenging and engaging. The exercise concluded with students discussing possible personal behavioural and broader societal responses to reduce the impacts of future climate change. The paper contends that such teaching to support students to become resilient young adults will be vital in a future world of environmental riskDouglas K. Bardsley and Annette M. Bardsle

Intragenomic internal transcribed spacer 2 variation in a genus of parasitoid wasps (Hymenoptera: Braconidae): implications for accurate species delimitation and phylogenetic analysis

A recent DNA barcoding study of Australian microgastrines (Hymenoptera: Braconidae) sought to use next-generation sequencing of the cytochrome c oxidase subunit 1 (COI) barcoding gene region, the wingless (WG) gene and the internal transcribed spacer 2 (ITS2) to delimit molecular species in a highly diverse group of parasitic wasps. Large intragenomic distances between ITS2 variants, often larger than the average interspecific variation, caused difficulties in using ITS2 for species delimitation in both threshold and tree-based approaches, and the gene was not included in the reported results of the previous DNA barcoding study. We here report on the intragenomic, and the intra- and interspecies, variation in ITS2in the microgastrine genus Diolcogasterto further investigate the value of ITS2as a marker for species delimitation and phylogenetics of the Microgastrinae. Distinctive intragenomic variant patterns were found in different species of Diolcogaster, with some species possessing a single major variant, and others possessing many divergent variants. Characterizing intragenomic variation of ITS2is critical as it is a widely used marker in hymenopteran phylogenetics and species delimitation, and large intragenomic distances such as those found in this study may obscure phylogenetic signal.E.P. Fagan-Jeffries, S.J.B. Cooper, T.M. Bradford and A.D. Austi