Judith Field

Human Adaptation and Plant Use in Highland New Guinea 49,000 to 44,000 Years Ago

New Guineas Ancient Colonies Isolated by water, Australia and New Guinea were some of the last major parts of the world colonized by modern humans. Summerhayes et al. (p. 78; see the Perspective by Gosden) describe an archaeological site in the highlands of New Guinea that sheds light on this migration. The record extends back to nearly 50,000 years ago and thus represents one of the earliest known records. Nuts and yams were widely consumed, and the variety of stone tools discovered implies that the early humans may have cleared forest patches to promote the growth of useful plants. Archaeological sites in the New Guinea Highlands trace the arrival of modern humans to nearly 50,000 years ago. After their emergence by 200,000 years before the present in Africa, modern humans colonized the globe, reaching Australia and New Guinea by 40,000 to 50,000 years ago. Understanding how humans lived and adapted to the range of environments in these areas has been difficult because well-preserved settlements are scarce. Data from the New Guinea Highlands (at an elevation of ~2000 meters) demonstrate the exploitation of the endemic nut Pandanus and yams in archaeological sites dated to 49,000 to 36,000 years ago, which are among the oldest human sites in this region. The sites also contain stone tools thought to be used to remove trees, which suggests that the early inhabitants cleared forest patches to promote the growth of useful plants.

Megafaunal extinction in the late Quaternary and the global overkill hypothesis

The global blitzkrieg hypothesis explains differential rates of megafaunal extinction between the worlds landmasses in the late Quaternary based on a proposed leap in predation efficiency enjoyed by colonising societies. It is characterised by appealing simplicity. Selective over hunting, facilitated by naiveté to human predation, produced rapid mass extinctions of large animals wherever subsistence societies colonised new landmasses. Taken at face value the circumstantial case for blitzkrieg is compelling and despite a paucity of direct evidence it has gained considerable support. Our review of the model suggests that it overlooks much contradictory data and rests on simplistic interpretations of complex biogeographicat and anthropological phenomena. These interpretations and assumptions do not account for major differences between the biotas, ecologies and human cultures of the landmasses involved. The assertion that responses of remote island species to human predation provide realistic models for those of continental taxa is poorly founded, exaggerating the likely predation efficiency of humans colonising continents. An absence of terrestrial predators over evolutionarily significant periods, together with restricted ranges and small populations, renders island faunas uniquely vulnerable to invaders. The argument, that climate cannot explain these phenomena because previous Glacial Maxima did not cause comparable extinctions, presupposes that their local effects were at least as severe as those of the Last Glacial Maximum. This has yet to be demonstrated and at most it would indirectly support a role for anthropogenic influence, not overkill per se. Overlooked or underplayed are the influences of translocated and other invading species. Similarly, differences in the origins, technologies and traditions of colonising human societies are rarely considered. These factors strongly impact on the predation efficiency, density and range of human populations, critically affecting the outcomes of predator-prey modeling. When a fuller constellation of influences and constraints is considered it is reasonable to posit that rapid mass extinction through selective human predation may largely describe megafaunal extinctions on remote islands, but the argument is not convincing for continents. This is especially so regarding Australia. Because even the largest Australian species were prey to endemic carnivores, their responses to human predation would not have been comparable to those of oceanic island species. No kill-sites or specialized big-game hunting/butchering tools are known and, on the basis of ethnographic and archaeological data, it is probable that predation efficiency, population density and range of the first Australians were insufficient to effect rapid mass extinction. Chronologies of human arrival and the disappearance of megafauna remain poor, but the most recent estimates for human-megafaunal coexistence in Australia range from 10,000 to 43,000 years. Although human predation may have been a contributing factor in megafaunal extinctions, rapid overkill is unlikely to describe the actual mechanism in most instances. The role of human predation and its significance relative to competing factors, human and otherwise, varied considerably between landmasses, as did the speeds with which extinctions occurred. Blitzkrieg and other mono-factorial models are heuristically valuable devices, but a growing body of evidence suggests that extinction can rarely, if ever, be attributed to a single cause.

Replication of KIAA0350, IL2RA, RPL5 and CD58 as multiple sclerosis susceptibility genes in Australians

A recent genome-wide association study (GWAS) conducted by the International Multiple Sclerosis Genetics Consortium (IMSGC) identified a number of putative MS susceptibility genes. Here we have performed a replication study in 1134 Australian MS cases and 1265 controls for 17 risk-associated single nucleotide polymorphisms (SNPs) reported by the IMSGC. Of 16 SNPs that passed quality control filters, four, each corresponding to a different non-human leukocyte antigen (HLA) gene, were associated with disease susceptibility: KIAA0350 (rs6498169) P=0.001, IL2RA (rs2104286) P=0.033, RPL5 (rs6604026) P=0.041 and CD58 (rs12044852) P=0.042. There was no association (P=0.58) between rs6897932 in the IL7R gene and the risk of MS. No interactions were detected between the replicated IMSGC SNPs and HLA-DRB1*15, gender, disease course, disease progression or age-at-onset. We used a novel Bayesian approach to estimate the extent to which our data increased or decreased evidence for association with the six most-associated IMSGC loci. These analyses indicated that even modest P-values, such as those reported here, can contribute markedly to the posterior probability of ‘true’ association in replication studies. In conclusion, these data provide support for the involvement of four non-HLA genes in the pathogenesis of MS, and combined with previous data, increase to genome-wide significance (P=3 × 10−8) evidence of an association between KIAA0350 and risk of disease.

Pleistocene seed-grinding implements from the Australian arid zone

Grinding-stones as a technology are seen as a key element in the artefactual transformations of the latest Pleistocene – both for themselves and the foods which were ground on them. In Australia, as in other regions, their age and status is also material to what (if any) kind of a broad-spectrum revolution in foraging accompanied them.

Climate change frames debate over the extinction of megafauna in Sahul (Pleistocene Australia-New Guinea)

Around 88 large vertebrate taxa disappeared from Sahul sometime during the Pleistocene, with the majority of losses (54 taxa) clearly taking place within the last 400,000 years. The largest was the 2.8-ton browsing Diprotodon optatum, whereas the ∼100- to 130-kg marsupial lion, Thylacoleo carnifex, the world’s most specialized mammalian carnivore, and Varanus priscus, the largest lizard known, were formidable predators. Explanations for these extinctions have centered on climatic change or human activities. Here, we review the evidence and arguments for both. Human involvement in the disappearance of some species remains possible but unproven. Mounting evidence points to the loss of most species before the peopling of Sahul (circa 50–45 ka) and a significant role for climate change in the disappearance of the continent’s megafauna.

Late Pleistocene Megafauna and Archaeology from Cuddie Springs, South-eastern Australia.

The Cuddie Springs site in south-eastern Australia provides the first evidence of an unequivocal association of megafauna with humans for this continent. Cuddie Springs has been known as a fossil megafauna locality for over a century, but its archaeological record has only recently been identified. Cuddie Springs is an open site, with the fossil deposits preserved in a claypan on the floor of an ancient ephemeral lake. Investigations revealed a stratified deposit of human occupation and fossil megafauna, suggesting a temporal overlap and an active association of megafauna with people in the lead up to the Last Glacial Maximum, when conditions were more arid than the present day. Two distinct occupation phases have been identified and are correlated to the hydrology of the Cuddie Springs lake. When people first arrived at Cuddie Springs, sometime before 30,000 BP, the claypan on the lake floor was similar to a waterhole, with five species of megafauna identified. Flaked stone artefacts were found scattered through this level. After the lake dried, there was human occupation of the claypan. The resource base broadened to include a range of plant foods. Megafauna appear to be just one of a range of food resources exploited during this period. A return to ephemeral conditions resulted in only periodic occupation of the site with megafauna disappearing from the record around 28,000 BP. The timing of overlap and association of megafauna with human occupation is coincident with the earliest occupation sites in this region. The archaeological evidence from Cuddie Springs suggests an opportunistic exploitation of resources and no specialised strategies for hunting megafauna. Disappearance of megafauna is likely to be a consequence of climatic change during the lead up to the Last Glacial Maximum and human activities may have compounded an extinction process well under way.

What did grinding stones grind? New light on Early Neolithic subsistence economy in the Middle Yellow River Valley, China

Grinding stones have provided a convenient proxy for the arrival of agriculture in Neolithic China. Not any more. Thanks to high-precision analyses of use-wear and starch residue, the authors show that early Neolithic people were mainly using these stones to process acorns. This defines a new stage in the long transition of food production from hunter-gatherer to farmer.

Resource pulses, switching trophic control, and the dynamics of small mammal assemblages in arid Australia

Abstract Small mammal assemblages in the aridlands of the Southern Hemisphere often have wildly fluctuating dynamics. Previous studies have attributed these fluctuations to climate-driven pulses in food resources resulting in the switching of trophic control from bottom-up (food-limited) to top-down (predation-limited) population regulation, and vice versa. In this study we use a meta-analytic approach to evaluate the evidence for the phenomenon of switching trophic control. If shifting trophic control is a unifying phenomenon that shapes small mammal assemblages in arid Australia, we would expect the abundance and species richness of small mammals to increase with increasing primary productivity and the abundance of small mammals to decrease with increasing predator abundances, which lag behind those of small mammals. We tested these predictions using data compiled from 6 unpublished and 2 published data sets containing time series (3–11 years) of small mammal and predator community dynamics. Our analyses provide moderate support for the notion that switching trophic control is a unifying phenomenon shaping small mammal assemblages. Also, our results provide evidence that top-down and bottom-up control are not mutually exclusive phenomena driving desert small mammal assemblages but rather alternative ecosystem states that exist along a rainfall-driven continuum of ecosystem energy flux through time.

Multiple Sclerosis Susceptibility-Associated SNPs Do Not Influence Disease Severity Measures in a Cohort of Australian MS Patients

Recent association studies in multiple sclerosis (MS) have identified and replicated several single nucleotide polymorphism (SNP) susceptibility loci including CLEC16A, IL2RA, IL7R, RPL5, CD58, CD40 and chromosome 12q13–14 in addition to the well established allele HLA-DR15. There is potential that these genetic susceptibility factors could also modulate MS disease severity, as demonstrated previously for the MS risk allele HLA-DR15. We investigated this hypothesis in a cohort of 1006 well characterised MS patients from South-Eastern Australia. We tested the MS-associated SNPs for association with five measures of disease severity incorporating disability, age of onset, cognition and brain atrophy. We observed trends towards association between the RPL5 risk SNP and time between first demyelinating event and relapse, and between the CD40 risk SNP and symbol digit test score. No associations were significant after correction for multiple testing. We found no evidence for the hypothesis that these new MS disease risk-associated SNPs influence disease severity.

The first archaeological evidence for death by spearing in Australia

An Aboriginal man done to death on the dunes 4000 years ago was recently discovered during excavations beneath a bus shelter in Narrabeen on Sydneys northern beaches. The presence of backed microliths and the evidence for trauma in the bones showed that he had been killed with stone-tipped spears. Now we know how these backed points were used. A punishment ritual is implied by analogies with contact-period observations made in the eighteenth century AD.